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Histology & Embryology Self Test Book Chief editor Liang yu (Lisa) Department of Histology & Embryology Tianjin Medical University 2013 -1- Preface Histology & Embryology is one of the very important basic medicine curricula. It also is the foundation on which Anatomy and Pathology, as well as Pathophysiology are built. To let students fully understand the basic knowledge and theories of the related specialties to be learned, to develop their capability to analyze and solve problems, and to build a good foundation for their further studying, we, based on our many years teaching experience, compile the book, Histology& Embryology Self Test Book. The book is for both International and Long-term-program's students, but is also as a reference for teachers to prepare their exam papers. The book includes self-tests and answers. The compiled book is mainly based on Basic Histology (12th ed. by the McGraw-Hill Companies, Inc. Luiz Carlos Junqueira, José Carneiro, 2007) , Netter’s Essential Histology ( by Elsevier Inc.William K.Ovalle, Partrick C. Nahirney, 2008), The Developing Human-Clinically Oriented Embryology ( 8 th ed. by Elsevier Inc . Keitb L. Moore, T.V. N. Persaud , 2008 ), and Langman’s Medical Embryology (8th ed. by Lippincott Williams &Wilkins, T.W. Sadler, 2006 ), and also refers to Basic Concepts in Cell Biology and Histology (by the McGraw-Hill Companies, Inc. James C. Mckenzie, Robert M.Klein ), Basic Concepts in Embryology (by the McGraw-Hill Companies, Inc. Lauren J.Sweeney), Netter’s Essential Histology ( by Elsevier Inc. William K. Ovalle, Patrick C. Nahirney, 2008) and The Developing Human –Clinically Oriented Embryology ( 8th ed. by Elsevier Inc.Keitb L. Moore, T.V. N. Persaud, 2008 ). The questions and problems in the book are raised from different styles and angles in order for each chapter core contents to be strengthened again and again. Participating editors: Ren yi-min, Liang yu, Hong wei, Li jin-ru, Wang jun-yan, Gao wei, Hu zhi-mei, Cui hong-mei, Lu zhi-hong, and Yao qing-bin. Due to the limitation of the editors' knowledge and experience, there should be some inappropriate or wrong content (s) in the edition.As the editors, from the bottom of our hearts, any suggestions and corrections are welcome and appreciated very much, and will be considered in the next edition. Chief editor Liang Yu (Lisa) February, 2013 -2- Contents Chapter 1 Epithelium …………………………………3 Lu zhi-hong Chapter 2 Connective tissue………………………….11 Hu zhi-mei Chapter 3 Cartilage and Bone ……………………….20 Lu zhi-hong Chapter 4 Muscular tissue……………………………28 Cui hong-mei Chapter 5 Nervous tissue…………………………….35 Cui hong-mei Chapter 6 Circulatory system………………………. .41 Wang jun-yan Chapter 7 Blood and Haemopoiesis………………. ...49 Hu zhi-mei Chapter 8 Lymphatic organs…………………………60 Wang jun-yan Chapter 9 Digestive tract……………………………..68 Gao wei Chapter 10 Digestive gland . . . . . . . . . . . . …... ….. Gao wei Chapter 11 Respiratory system …... …... …... …... . . 84 Hong wei Chapter 12 Urinary system……………………… …... 88 Ren Chapter 13 Endocrine system…………………… ….. .94 Liang Chapter 14 Eyes and Ears…………………………. . .106 Yao qing-bin Chapter 15 Skin …………………………………… 113 Ren yi-min Chapter 16 Male Reproductive System……………. 119 Li jin-ru Chapter 17 Female Reproductive System…………. 126 Li jin-ru Chapter 18 General human embryology ………… .134 -3- .76 Liang yi-min yu yu EPITHELIUM Ⅰ. Definitions 1. endothelium 2. mesothelium 3. microvillus(micovilli) 4. cilium(cilia) 5. junctional complex 6. basement membrane Ⅱ. Fill in the blanks 1. The human body is composed of only four basic types of tissue: , , , and . 2. Epithelia can be divided into two main groups according to their structure and function: and . 3. Covering epithelia are classified according to the number of cell layers and the morphologic features of the cells in the surface layer. contain only one layer of cells and contain more than one layer. 4. Epithelial cells generally show polarity, the surface of the cell that faces the connective tissue is called , whereas the opposite surface, usually facing a space, is and the surface apposed in neighboring cells are . 5. Basement membrane is formed by and . 6. The lateral membranes of epithelial cells exhibit four specialized intercellular junctions, they are and , , . 7. Exocrine glands have a , which contains the cells specialized for secretion, and , which transport the secretion out of the gland. Ⅲ. Questions -4- 1. List the general features of the epithelium. 2. List the classification and distributions of the covering epithelium. Ⅳ. Choose the correct answers for each question. 1. All of the following are features of epithelium EXCEPT( ) A. more cells and less intercellular substance B. cells are tightly joined with an very narrow intercellular space C. have free surface and basal surface D. rich in capillaries and nerve endings E. cover the external and internal surface of the body 2. Simple squamous epithelium relates to all of the following EXCEPT the( ) A. surface of heart B. endothelium C. mesothelium D. parietal layer of renal capsule E. luminar surface of small intestine 3. Simple cuboidal epithelium covers the surface of the( A. thyroid follicles B. intestine C. uterus D. pulmonary alveoli E. cornea 4. Simple columnar epithelium is lining of the( A. respiratory passages B. seminiferous tubules C. ureters D. uterus E. proximal tubules in kidney -5- ) ) 5. Which is NOT a characteristic of the pseudostratified ciliated columnar epithelium?( ) A. It consists mainly of 4 types of cells B. Only the columnar cells rest on the besement membrane C. Columnar cells have cilia D. Goblet cells secrete mucus E. It lines respiratory passages 6. Keratinized stratified squamous epithelium is present in the( ) A. esophagus B. thyroid C. intestine D. skin E. urinary bladder 7. Which of the following descriptions relates to the cilium?( A. 9+2 microtubules B. microfilaments C. brush-like border D. cell coat on the surface E. connected to the terminal web 8. In the core of microvilli there are some( A. microfilaments B. microtubules C. intermediate filaments D. tonofilaments E. myofilaments 9. The function of the microvilli is to ( ) A. remove small particles on the surface B. increase adhesion between adjacent cells C. increase absorptive area -6- ) ) D. communicate adjacent cells E. increase permeability 10. Desmosome( ) A. is a specialization at the basal surface of epithelium B. is belt-shaped C. is particularly well-developed in the epidermis D. is composed of the basal lamina and the reticular lamina E. serves as a semi-permeable membrane 11. The connexon of gap junction refers to all the following descriptions EXCEPT( ) A. A bridging structure spans the adjacent cellular membranes B. consists of six sub-units of protein C. The sub-units arrange around a central channel D. Adjacent cells communicate through the central channels E. increases the absorptive area 12. Which of the following descriptions is NOT true of the basement membrane?( ) A. a member of the junctional complex B. located between epithelium and underlying connective tissue C. consists of the basal lamina and the reticular lamina D. positive staining with PAS E. observed with silver stain 13. Secretions of endocrine gland are usually( A. released into nearby vascular supply B. released into simple ducts C. stored within cells D. released into branched ducts E. released into alveolus -7- ) 14. Which is NOT a function of epithelium?( ) A. absorption and secretion B. transport and excretion C. protection D. sensory reception E. nutrition 15. The transitional epithelium exists in the( ) A. urethra B. urinary bladder C. esophagus D. stomach E. transitional portion between uterus and vagina Ⅴ. Choose the true or false by “T” & “F” 1. Covering epithelia cover the external and internal surfaces of the body, including the linings of vessels and other small cavities.( ) 2. Epithelium usually has a free surface and a basal surface, both of which possess the same structure but different function.( ) 3. The core of the microvilli contains fine actin filaments, which interconnected with the terminal web.( ) 4. Between opposing cell membrane, where the gap junction occurs, numerous connexons span. Ions and small molecules can pass freely between opposed epithelial cells via the gap junction.( ) 5. Between the epithelium and the underlining connective tissue is the basement membrane.( ) 6. The basement membrane provides for a strong connection, increases the basal surface area and serves as a semi-permeable membrane.( ) 7. Blood vessels and nerves never pass through the basement membrane and penetrate into epithelial tissues.( ) -8- 8. Plasma membrane infoldings promote transportation of water and ions without energy consume.( ) 9. Specializations of the basal surface of epithelium are basement membrane, desmosome, hemidesmosome, and plasma membrane infolding.( ) 10. The secretions of exocrine gland are discharged through a duct system and the secretions of endocrine glands are directly released into the bloodstream.( ) ANSWERS Ⅰ. Definitions 1. endothelium The simple squamous epithelium lining the inner surfaces of the heart, blood vessels and lymphatic vessels is termed endothelium. 2. mesothelium The simple squamous epithelium covering the outer surfaces of the pleura, peritoneum and pericardium is termed mesothelium. 3. microvilius( micovilli) Microvilli are microscopic cellular membrane protrusions that increase the surface area of cells, and they are covered in plasma membrane, which encloses cytoplasm and microfilaments. 4. cilium(cilia) Minute hair-like processes that extend from a cell surface, composed of nine pairs of microtubules around a core of two microtubules. They beat rhythmically to move the cell or to move fluid or mucus over the surface. 5. junctional complex An attachment point between epithelial cells composed of a number of complex structures, including desmosomes, tight junctions, adherent junction and gap junctions. 6. basement membrane -9- A sheet of amorphous extracellular material upon which the basal surfaces of epithelial cells rest.; it is formed by the combination of a basal lamina and a reticular lamina. Ⅱ. Fill in the blanks 1. epithelial tissue, connective tissue, muscle tissue, nervous tissue 2. covering epithelia, glandular epithelia 3. simple epithelia, stratified epithelia 4. basal surface, free surface, lateral surface 5. basal lamina, reticular lamina 6. desmosomes, tight junctions, adherent junction, gap junctions 7. secretory portion, ducts Ⅲ. Questions 1. List the general features of the epithelium. (1) Epithelial tissues composed of closely aggregated cells with very little extracellular substance, form cellular sheets ; (2) Epithelial cells generally show the polarity, have free surface, basal surface and lateral surface; (3) Avascular ; (4) Rich in nerve endings. 2. List the classification and distributions of the covering epithelium. Classification Distribution simple squamous epithelium endothelium, inner surfaces of the heart, blood vessels and lymphatic vessels mesothelium, the outer surfaces of the pleura, peritoneum and pericardium parietal layer of renal capsule, pulmonary alveoli - 10 - simple cuboidal epithelium thyroid follicles, renal tubules simple columnar epithelium stomach, intestine, uterus pseudostratified ciliated columnar trachea epithelium stratified squamous epithelium keratinized : epidermis of skin, nonkeratinized : mouth, esophagus, and vagina stratified columnar epithelium conjunctiva lining the eyelids transitional epithelium urinary bladder, ureter, and the upper part of urethra Ⅳ. Choose the correct answer exists for each question. 1. D 10. C 2. E 11. E 3. A 12. A 4. D 5. B 13. A 6. D 14. E 7. A 8. A 9. C 15. B Ⅴ. Choose the true or false by “T” & “F” 1. T 2. F 3. T 4. T 5. T 6. F 7. T 8. F 9. F 10. T Lu zhi-hong - 11 - CONNECTIVE TISSUE Ⅰ. Definitions 1. fibroblast 2. macrophage 3. mast cell 4. plasma cell II. Fill in the blanks 1. The connective tissue originates from the . 2. Connective tissue proper is classified into four types: , and , . 3. Seven types of cells are present in loose connective tissue: , , , , , , and . 4. The extracellular matrix is composed of fibers, ________and ________ in connective tissue. 5. There are three types of fibers in loose connective tissue: and , . 6. Macrophages are derived from in blood, and when seen under the electron microscope, macrophages are rich in and in their cytoplasm. 7. Fibroblasts are and , in shape. Their nuclei are in size with fine chromatin; the cytoplasm is weakly electron microscope shows the cytoplasm to be rich in and . 8. Plasma cells are formed from produce and their function is to , which play the key role in the body’s humoral immune reaction. 9. Plasma cells are characterized by distribution of heterochromatin. - 12 - -staining nuclei with a . The 10. The cytoplasm of mast cells is filled with numerous coarse basophilic , which stain contain , with toluidine blue and , , and other bioactive chemicals. III. Questions 1. Describe the structural features of connective tissue. 2. List the components of loose connective tissue. IV. Choose the correct answer for each question. 1. The characteristics of connective tissue are all of the following EXCEPT( ) A. a small number of cells and a large amount of intercellular substance B. the cells possess free surface and basal surface C. It contains blood and lymphatic vessels, nerves D. functions of support, connection, nutrition and defense E. none of the above 2. Which of the following does NOT belong to connective tissue?( A. reticular tissue B. osseous tissue C. cartilage tissue D. lymphoid tissue E. blood 3. All of followings are components of loose connective tissue EXCEPT( ) A. collagenous fibers B. elastic fibers C. goblet cells D. fibroblasts E. macrophages - 13 - ) 4. All of following characteristics belong to the reticular fiber EXCEPT( ) A. with a surface coat of carbohydrates B. composition of elastin and microfibrils C. positive staining of PAS D. argyrophilic E. periodic cross-bandings in EM 5. The elastic fibers ( ) A. consist of elastin and microfibrils B. consist of fibrils C. are PAS positive D. are argyrophilic E. show periodic cross-bandings in EM 6. Which is NOT true of ground substance in loose connective tissue? ( A. Jelly-like and amorphous B. collagenous fibers are main component C. consists of proteoglycans & glycoproteins D. forms a molecular sieve E. Acts as a barrier to spread of microorganisms 7. The commonest cells in loose connective tissue is the ( A. mast cells B. undifferentiated cells C. macrophages D. fibroblasts E. plasma cells 8. Which is NOT a characteristic of fibroblasts? ( ) A. large, stellate shape with processes B. located close to collagenous fibers C. have a large, pale nucleus with obvious nucleoli - 14 - ) ) D. rich in rough endoplasmic reticulum and well-developed Golgi complex E. take part in the immune reaction 9. The collagen necessary to form scar tissue is produced by( ) A. fibroblasts B. undifferentiated cells C. macrophages D. mast cells E. plasma cells 10. Which is NOT a characteristic of the plasma cells? ( ) A. ovoid cell with eccentric nucleus B. has a strong basophilic cytoplasm C. full of dense granules in cytoplasm D. derived from B lymphocytes E. rich in RER and well-developed Golgi apparatus 11.Which of the following has ultrastructural features of protein-secreting cells? ( ) A. mast cells B. fibrocytes C. macrophages D. plasma cells E. fat cells 12.Which is NOT true of macrophages? ( ) A. have acidophilic cytoplasm B. have nucleus like clock-face C. are derived from the monocytes D. have numerous lysosomes and phagosomes E. are highly motile - 15 - 13. Heparin is produced by which of the following cells? ( ) A. hepatocytes or hepatic cells B. undifferentiated cells C. macrophages D. eosinophils E. mast cells 14.Intercellular substance in connective tissue is produced by( A. fat cells B. fibrocytes C. plasma cells D. mast cells E. fibroblasts 15. Histamine is released by ( ) A. fibroblasts B. fibrocytes C. mast cells D. plasma cells E. macrophages 16. The chief component of dense connective tissue is( A. collagenous fibers B. reticular fibers C. fibroblasts D. fibrocytes E. ground substance 17. Reticular tissue is mostly distributed in( A. lymphoid organ B. circulatory organ C. urinary organ - 16 - ) ) ) D. reproductive organ E. digestive organ Ⅴ. Choose the true or false by “T” & “F” 1. The cells in connective tissue usually have polarity. ( ) 2. The only significant function of connective tissue is to provide structural support for other tissues. ( ) 3. Adipose tissue is also termed the areolar tissue. ( ) 4. Hyaluronic acid is the principal constituent of ground substance in loose connective tissues. ( ) 5. The ultrastructure of the fibroblast is typical of a cell involved in secreting steroid hormones. ( ) 6. Mesenchyme is the embryological precursor of all connective tissues, including cartilage and bone tissuses. ( ) 7. Mast cells exhibit the property of metachromasia when stained with certain blue basic dyes. ( ) 8. Elastic fibers are also called yellow fibers because they are yellow in fresh state. ( ) 9. Lipid is contained in a large membrane bound vesicle in fat cells. ( ) 10. Reticular tissue is mainly composed of fibroblasts and reticular fibers. ( ) ANSWERS Ⅰ. Definitions 1. Fibroblast Fibroblast is the commonest cell in loose C.T.. L.M.: large, flat or stellate in shape, with branching processes Nucleus: large, oval, pale with 1~2 distinct nucleoli Cytoplasm: E.M.: weakly basophilic rich in RER, free ribosomes, well developed Golgi apparatus - 17 - Function: the synthesis of fibers and ground substance 2. Macrophage Macrophages is the second major cell in loose C.T.. L.M.: irregular in shape, with short and blunt processes Nucleus: small, round, dark with indistinct nucleoli Cytoplasm: E.M.: a few small vacuoles and particles, acidophilic irregular surface, numerous projections rich in lysosomes, pinosomes, phagosomes Function: Macrophages are important cells of defense (a) mobility and chemotaxis (b) phagocytic ability (c) contributed to the immune reactions of the body (d) synthesis and secrete many bio-active products Macrophages are derived from the monocytes in biood 3. Mast cell Mast cell lies along the course of small blood vessels L.M.: large, round or ovoid in shape Nucleus: small, pale Cytoplasm: E.M.: is filled with numerous coarse basophilic granules granules are bounded by a unit membrane containing: heparin, histamine, slow-reacting substance, eosinophil chemotactic factors Function: is involved in allergic reaction 4. Plasma cell L.M.: is numerous in C.T. of digestive and respiratory tracts ovoid or round in shape Nucleus: round, located eccentrically, deeply-stained chromatin is arranged like numbers on a clock-face Cytoplasm: abundant, intensely basophilic, lightly-stained area near nucleus - 18 - E.M.: extensive RER, ribosomes, well-developed Golgi apparatus Function: produce antibodies---immunoglobulins, take part in humoral immune reaction. Plasma cells are derived from the B-lymphocytes in biood. II. Fill in the blanks 1. mesenchyme. 2. loose connective tissue, dense connective tissue, adipose tissue, reticular tissue. 3. fibroblasts, macrophages, plasma cells, mast cells, fat cells, undifferentiated mesenchymal cells, leukocytes. 4. ground substance, tissue fluid. 5. collagenous fibers, elastic fibers, reticular fibers. 6. monocytes, lysosomes, pinosomes, phagosomes. 7. spindle(fusiform), large, pale, basophilic, RER(rough endoplasmic reticulum), free ribosomes. 8. B-lymphocytes, antibodies(immunoglobulins). 9. dence, clock-face. 10. granules, metachromatically, heparin, histamine, slow-reacting substance, eosinophil chemotactic factors. III. Questions 1. Describe the structural features of connective tissue. The connective tissue has following features: (a) A relatively small number of cells is distributed throughout a large amount of extracellular matrix. The extracellular matrix is composed of fibers, ground substance and tissue fluid. (b) The connective tissue is divided into different types according to physical properties of ground substance. (c) The connective tissue is widely distributed in the body. - 19 - (d) The connective tissue cells don’t have polarization and basement membrane, but connective tissue is rich in blood and lymphatic vessels. (e) The connective tissue connects, holds and supports other tissues. It also plays a role in nutrition, defense and repair. (f) All connective tissues originate from the mesenchyme which is embryonic connective tissue . 2. List the components of loose connective tissue. Loose connective tissue is composed of cells and extracellular matrix. fibroblasts macrophages plasma cells Cells mast cells fat cells undifferentiated mesenchymal cells leukocytes collagenous fibers fibers elastic fibers Extracellular matrix reticular fibers ground substance tissue fluid IV. Choose the correct answer for each question. 1. B 11. D 2. D 12. B 3. C 13. E 4. B 5. A 14. E 6. B 15. C 7. D 16. A 8. E 9. A 10. C 17. A Ⅴ. Choose the true or false by “T” & “F” 1. F 2. F 3. F 4. T 5. F 6. T 7. T 8. T 9. F 10. F Hu zhi-mei - 20 - CARTILAGE AND BONE Ⅰ. Definitions 1. isogenous group 2. bone lamella 3. osteoid 4. osteon Ⅱ. Fill in the blanks 1. Cartilage consists of cells called cavities called located in matrix , and extracellular matrix composed of fibers and ground substance. 2. There are three types of cartilage, they are and , . 3. Further growth of cartilage is attributable to two processes: , resulting from the mitotic division of preexisting chondrocytes; and , resulting from the differentiation of perichondrial cells. 4. Bone is a specialized connective tissue composed of calcified intercellular material, called , , and four cell types: and . , are responsible for the synthesis of the organic components of bone matrix. 5. All bones are lined on both internal and external surfaces by layers of connective tissue containing mesenchymal stem cells called on the internal surface and , on the external surface. 6. Osteocyte is enclosed within spaces called processes occupy the contact via , and its cytoplasmic . Processes of adjacent cells make , and molecules are passed via these structures from cell to cell. - 21 - 7. In compact bone, the calcified bone matrix are organized as lamellae, there are four types of lamellae, and , , . 8. Each osteon consists of a , containing blood vessels, nerves, and loose connective tissue, surrounded by 4–10 concentric . Ⅲ. Questions 1. List the classification, distribution and general features of the cartilage. 2. Describe the organization patterns of the compact bone. Ⅳ. Choose the correct answers for each question. 1. The principle of classification for the cartilage tissue is the ( ) A. number of containing cells B. shape of containing cells C. quantity and type of containing fibers D. type of ground substance E. function of cartilage 2. Cartilage capsule is ( ) A. loose connective tissue at the surface of cartilage B. dense connective tissue at the surface of cartilage C. space around cartilage cells D. cartilage matrix around cartilage cells E. collagenous fibers around cartilage cells 3. Which of the following is found as the coating for the articular ends of bones at joints ? ( ) A. hyaline cartilage B. elastic cartilage C. fibrocartilage D. bone E. dense connective tissue - 22 - 4. The major skeletal component of the external ear is ( ) A. dense irregular connective tissue B. dense regular connective tissue C. hyaline cartilage D. bone E. elastic cartilage 5. Hyaline cartilage tissue does NOT contain ( ) A. cells that can divide B. ground substance C. fibers D. blood vessels E. hyaluronic acid 6. Which of the following about hyaline cartilage is FALSE? ( ) A. Chondrocytes have basophilic cytoplasm B. Chondrocytes at periphery are immature and single located C. Chondrocytes in the center of a mass of cartilage are present in groups D. Matrix surrounding the chondrocytes is acidophilic E. Collagen fibrils are present 7. Isogenous group is ( ) A. seen at periphery of cartilage B. seen at periphery of bone C. a group of chondrocytes derived from one single parent cell D. a group of chondrocytes derived from different cells E. a group of immature flattened chondrocytes 8. Bone tissue contains ( ) A. collagenous fibers B. elastic fibers C. reticular fibers - 23 - D. chondrocytes E. none of the above 9. Osteoid tissue is produced by ( ) A. osteocytes B. osteoblasts C. osteoclasts D. osteoprogenitor cells E. mesenchymal cells 10. Which of the following is related to the osteocytes? ( ) A. The cell body occupies a lacuna B. The ground substance surrounding cells is strong basophilic C. Cells are round with no processes D. Cells are distributed in groups E. Cells metabolize independently 11. Osteocytes possess all of the following characteristics EXCEPT ( A. They are present in lacunae B. Many fine processes extend into canaliculi C. Adjacent processes contact with desmosomes D. They have acidophilic or weakly basophilic cytoplasm E. They obtain nutrients from tissue fluid 12. Beside osteocytes, bone lacunae also contain ( A. blood B. tissue fluid C. lymphatic vessels D. blood vessels E. nerves 13. Perichondrium and periosteum contain ( A. osteocytes B. osteoblasts - 24 - ) ) ) C. osteoclasts D. osteoprogenitor cells E. chondrocytes 14. Osteoprogenitor cells can differentiate into ( ) A. osteocytes B. osteoblasts C. osteoclasts D. fibroblasts E. none of the above 15. Which of the following is NOT true of bone matrix? ( ) A. stains acidophilic in H & E sections B. contains inorganic salts C. contains collagen fibers D. has a higher sulfates than that of cartilage E. arranges regularly in lamellae 16. An important feature in nutrition of cartilage is its( ) A. system of lacunae and canaliculi B. sinusoids C. lymphatics D. nutrient arteries E. high water (tissue fluid) content of the matrix Ⅴ. Choose the true or false by “T” & “F” 1. Cartilage and bone tissues belong to connective tissue proper. ( ) 2. Three types of cartilage can be distinguished by reference to the differences in quantity and type of cells. ( ) 3. Chondrocytes in fibrocartilage are completely enclosed by cartilage matrix and occupy small laculae. ( ) 4. The inner layer of perichodrium is rich in osteoprogenitor cells, which are - 25 - responsible for appositional growth of cartilage. ( ) 5. Osteoblasts secrete fibers and organic ground substance and embed themselves into the bone matrix, thus the osteoid tissue is formed. ( ) 6. Osteocytes and their processes are suspended in tissue fluid within lacunae and analiculi, thus the nutrients and metabolites can be exchangeed between the blood and the osteocytes. ( ) 7. Osteoclasts secrete lysosomal enzymes, which break down the collagen and organic ground substance, thus the bone matrix is absorbed. ( ) 8. The structural form of bone matrix is bone lamellae, which are present in the compact bone but not in the spongy bone. ( ) 9. In the bone tissue, the collagenous and elastic fibers are embedded in the amorphous ground substance, and characteristically arranged in lamellae. ( ) 10. Osteons consist of Haversian lamellae and a central Volkmann’s canal in which blood vessels and nerves pass through. ( ) ANSWERS Ⅰ. Definitions 1. isogenous group In the center of hyaline cartilage, chondrocytes are round and may appear in groups of up to eight cells originating from mitotic divisions of a single chondrocyte. These groups are called the isogenous group. 2. bone lamella The calcified bone matrix organized as multiple layers is termed bone lamella, it is a basic structural unit of mature bone. 3. osteoid The organic matrix of bone is termed osteoid; it has not undergone calcification. 4. osteon - 26 - The basic unit of structure of compact bone, comprising a haversian canal and its concentrically arranged haversian lamellae. Ⅱ. Fill in the blanks 1. chondrocytes, lacunae 2. hyaline cartilage, elastic cartilage, fibrocartilage 3. interstitial growth, appositional growth 4. bone matrix, osteocytes, osteoblasts, osteoclasts, osteoprogenitor cells. Osteoblasts 5. osteoprogenitor cells, endosteum, periosteum 6. lacunae, canaliculi, gap junctions 7. osteon, external circumferential lamellae, inner circumferential lamellae, interstitial lamellae 8. central canal, haversian lamellae Ⅲ. Questions 1. List the classification, distribution and general features of the cartilage. Classification hyaline cartilage elastic cartilage Chondrocyte located in lacunae located in lacunae Extracellular containing containing elastic matrix collagen fibrils fibers articular surfaces the auricle of the ear, of the movable Distribution the walls of the joints, the walls of external auditory larger respiratory canals, the auditory passages (nose, (eustachian) tubes, larynx, trachea, the epiglottis, and the bronchi), the cuneiform cartilage ventral ends of ribs - 27 - in the larynx fibrocartilage located in lacunae containing coarse collagen fibers intervertebral disks, attachments of certain ligaments, and the pubic symphysis 2. Describe the organization patterns of the lamellae in the compact bone. In compact bone, the lamellae are quite organized, either parallel to each other or concentrically around a vascular canal. There are four types of lamellaes, (1) Osteon(Haversian system) is a long, often bifurcated cylinder generally parallel to the long axis of the diaphysis, and is the basic unit of structure of compact bone. It consists of a central canal surrounded by 4–10 concentric lamellae. Each canal contains blood vessels, nerves, and loose connective tissue. (2) Inner circumferential lamellae are located around the marrow cavity. (3) External circumferential lamellae are located immediately beneath the periosteum. (4) Interstitial lamellae are located between the Haversian systems, they are numerous irregularly shaped groups of parallel lamellae. These structures are lamellae remaining from osteons partially destroyed by osteoclasts during growth and remodeling of bone. Ⅳ. Choose the correct answer exists for each question. 1. C 11. C 2. D 12. B 3. A 4. E 13. D 5. D 6. D 14. B 7. C 15. D 8. A 9. B 10. A 16. E Ⅴ. Choose the true or false by “T” & “F” 1.F 2. F 3. T 4. T 5. T 6. T 7. T 8. F 9. F 10. F Lu zhi-hong - 28 - MUSCULAR TISSUE Ⅰ. Definitions 1. sarcomere 2. intercalated disk 3. triad II. Fill in the blanks 1. Combining the functional and structural features, three types of muscle tissue can be recognized: 2. Numerous nuclei , and . located is helpful in distinguishing ske- letal muscle from cardiac and smooth muscle, both of which have located nuclei. 3. Muscle fibers show cross-striation of alternating dark and light bans. The dark bands are termed , and the light bands are termed . The light band is intersected by a thin dark line, termed . There is a pale band, termed , in the middle of which band, presented a very fine dark strip, termed . 4. Sarcomere is a segment myofibril between two adjacent composed of band, lines, band, and 5. A triad is composed of the two band. _and a . 6. A dense connective tissue sheath, termed , envelops the entire muscle. Within the muscle each bundle of muscle fibers is surrounded by a thin layer of connective tissue, termed . Within a bundle, each muscle fiber is covered by delicate , termed . 7. The prominent dark striations at regular intervals across the cardiac fiber, exhibiting a step-like or zigzag pattern, are termed . III. Questions Compare the structural features of three types of muscle tissue under light microscope. IV. Choose the correct answers for each question. - 29 - 1. A cross section through the H band of a sarcomere displays( ) A. both thick and thin filaments B. only thick filaments C. only thin filaments D. a zig-zag network filaments E. no filaments 2. Where is the Z line situated in a sarcomere?( ) A. In the middle of the A band B. In the middle of the I band C. In the middle of the H band D. In between A and I bands E. In between A and H bands 3. The T tubules of skeletal muscle is continuous with( ) A. A band B. Z line C. nuclear membrane D. cell membrane E. sarcoplasmic reticulum 4. The wave of contraction is spread from cell to cell in cardiac muscle by ( ) A. motor endplates B. intercalated discs C. muscle spindles D. dense bodies E. none of above 5. With respect to cardiac muscle fibers, all of the following are true EXCEPT( ) A. the nuclei are centrally located B. they are multinucleated fibers - 30 - C. they are branched fibers D. they contain abundant mitochondria E. cross striations are found 6. Smooth muscle cells do NOT generally display( ) A. sarcoplasm B. sarcolemmas C. sarcomere D. prominent nuclei E. both actin and myosin 7. A sarcomere consists of ( ) A. 1/2 I band + A band + 1/2 I band B. 1/2 A band + I band + 1/2 A band C. 1/2 I band + 1/2 A band D. 1/2 I band + A band E. I band + A band 8. The component of the thick filaments is( ) A. actin B. myosin C. tropomyosin D. troponin E. myoglobin 9. The terminal cisternae of skeletal muscle are formed by( ) A. cell membrane B. RER C. Golgi complex D. T tubules E. L tubules 10. Which of the following statements about the nucleus of skeletal muscle cells is true? ( ) - 31 - A. one nucleus located in the center of the cells B. several nuclei in the center of the cells C. one nucleus beneath the sarcolemma D. many nuclei beneath the sarcolemma E. many nuclei scattered in the sarcoplasm 11. All of the following are morphological features of skeletal muscle fibers EXCEPT( ) A. long cylindrical cells B. many elongated nuclei in the center of the cell C. distinct cross striations D. rich SER E. abundant mitochondria 12. Which of the following statements about the myofibril is FALSE? ( A. the basic structure related to contraction of three types of muscle tissue B. made up of thick and thin filaments C. showing A and I bands, H band, Z and M lines D. surrounded by T and L tubules E. the shortest unit in it is called sarcomere 13. Which of the following statements about the sarcoplasmic reticulum of the striated muscle is FALSE? ( ) A. It is specialized SER B. Main branches run transversely and anastomose into network C. The ends of it form the terminal cisternae D. The calcium pumps can be found on its membrane E. Its function is to store Ca2+ 14. When contracting the myosin heads bind to ( A. Ca2+ B. ATP C. troponin - 32 - ) ) D. actin E. tropomyosin 15. The change in the sarcomere during contraction is( ) A. A and H bands shorten B. A band shortens C. I and H bands shorten D. I and A bands shorten E. A, I and H bands shorten V. Choose the true or false by “T” & “F” 1. Muscle cells are often termed muscle fibers because they contain numerous myofibrils in sarcoplasm. ( ) 2. The skeletal T-tubules are invaginations of sarcolemma at the level of the Z-line. ( ) 3. The sarcoplasmic reticulum of the striated muscle is specialized SER. ( ) 4. Electron microscopy of skeletal fibers reveals that the myofibrils consist of thick filaments and thin filaments. ( ) 5. There are thick filaments and thin filaments located in Smooth fibers, but no myofibrils. ( ) 6. The thin filaments are composed of myosin . ( ) 7. The triads of skeletal fibers and cardiac fibers are located at the A-I junction level. ( ) 8. A-band only contains think filaments. ( ) 9. Thin filaments are only located at I-bands. ( 10. H-band are only contains think filaments. ( ANSWERS Ⅰ. Definitions 1. sarcomere - 33 - ) ) Sarcomere is a segment myofibril between two adjacent Z-lines, composed of 1/2 I band, A band, and 1/2 I band. It is a unit of the structure and function of the myofibril. 2. intercalated disk The prominent dark striations at regular intervals across the cardiac fiber, exhibiting a step-like or zigzag pattern, are termed intercalated disk, actually junctions between cardiac muscle cells. 3. triad The two terminal cisternae together with a central T-tubule, at the A-I junction level of skeletal muscle fiber are termed triad. II. Fill in the blanks 1. skeletal muscle, cardiac muscle, smooth muscle 2. peripheral, central 3. A band, I band, Z line, H band, M line 4. Z, 1/2 I, A, 1/2 I 5. terminal cisternea, transverse tubule 6. epimysium, perimysium, connective tissue, endomysium 7. intercalated disk III. Questions Compare the structural features of three types of muscle tissue under light microscope. Skeletal muscle Shape long cylindrical Cardiac muscle short column Smooth fusiform branch Nucleus multinucleated Location Peripheral location Cross striation Intercalated disk one or two central location distinct less distinct no yes - 34 - one central no no IV. Choose the correct answers for each question. 1. B 2. B 3. D 4. B 5. B 6. C 7. A 8. B 9. E 10. D 11. B 12. A 13. B 14. D 15. C V. Choose the true or false by “T” & “F” 1. F 2. F 3. T 4. T 5.T 6. F 7. F 8. F 9. F 10.T Cui hong-mei - 35 - NERVOUS TISSUE I. Definitions 1. Nissl body 2. neurofibril 3. synapse 4. nerve fiber 5. blood-brain barrier II. Fill in the blanks 1. Nervous tissue consists of two classes of cell: 2. A neuron consists of two parts: and and . . 3. Neurons have two types of plasmatic processes: and . 4. Nissl bodies are present in the cytoplasm of but absent from and and . 5. A chemical synapse consists of , , and . 6. In central nervous system, four types of neuroglial cells are identified: , , and . 7. Myelinated nerve fibers of peripheral nervous system are composed of , and . 8. The myelin-forming cells in the peripheral nervous system are , but in the central nervous system are 9. The tactile corpuscles are found in the . . 10. The postsynaptic membrane of motor end plate is _______. III. Questions 1. Describe the structure of the neuron soma 2. Describe the structure of myelinated nerve fiber in peripheral nervous system. IV. Choose the correct answers for each question. - 36 - 1. Neurotransmitters are stored in and released from( ) A. synaptic vesicles B. mitochondria C. lysosomes D. RER E. SER 2. The myelin sheath of the peripheral nerve consists of( ) A. Schwann cell membrane and cytoplasm B. only Schwann cell cytoplasm C. multiple layers of the Schwann cell membrane and a little Schwann cell cytoplasm D. only the lipid of Schwann cell membrane E. Schwann cell membrane and basal lamina 3. The axons of neurons( ) A. are all very long B. are never branches C. contain no neurofibrils D. can not synthesize proteins E. usually one or two axons per neuron 4. Perineurium ( ) A. is connective tissue encasing single nerve fiber B. is connective tissue surrounding bundles of nerve fibers C. is the cell membrane of Schwann cells D. is the basal membrane of Schwann cells E. is muscle tissue with a little connective tissue 5. Nodes of Ranvier are( ) A. seen in all types of nerve fibers B. only seen in the myelinated nerve fibers of the PNS C. only seen in the unmyelinated nerve fibers of the CNS - 37 - D. sites where myelin sheath and neurolemma are interrupted E. the reason for slower conduction of impulses 6. The most numerous type of neurons in the human body are ( ) A. sensory, pseudounipolar neurons B. sensory, bipolar neurons C. motor, multipolar neurons D. bipolar, interneurons E. multipolar, interneurons 7. Which of the following is a feature of axons or dendrites, but not of both( ) A. Synapse formation B. Mitochondria C. Neurofilaments D. Nissl bodies E. Microtubules 8. Electrical synapse is ( ) A. tight junction B. intermediate junction C. gap junction D. desmosome E. hemidesmosome 9. The reason for rapid conduction of impulses along myelinated nerve fibers is that they have( ) A. long axons B. thick axons C. many synaptic vesicles in the axons D. clefts of Schmidt and Lantermann E. nodes of Ranvier - 38 - 10. According to a popular hypothesis microglial cells are derived from( ) A. fibroblasts B. ependymal cells C. monocytes D. astrocytes E. neuroectodermal cells V. Choose the true or false by “T” & “F” 1. Most of sensory neurons are multipolar neurons. ( ) 2. Neurofibrils collect together to form nerve fibers. ( ) 3. The longer the axon, the bigger the cell body of the parent neuron. ( ) 4. Microtubules and microfilaments are present in the perikarya, but do not extend into the axon and axon hillock. ( ) 5. The dendritic spines are the sites to form synaptic contacts and receive information.( ) 6. Synaptic transmission involves that neurotransmitters are released into synaptic cleft and then bind to the receptors on the postsynaptic membrane producing action potential.( ) 7. In general, the shorter the internodes, the more the nodes of Ranvier and therefore, the greater the conduction velocity. ( ) 8. Neuroglial cells can only be found in the gray matter but not in the white matter of the CNS. ( ) ANSWERS I. Definitions 1. Nissl bodies Location: in soma and dendrite L.M. basophilic granular areas E.M. are RER and free ribosome, Golgi complex Function: synthesize proteins - 39 - 2. neurofibrils Location: in soma, axon and dendrite L.M. dark brown filaments E.M. neurofilaments Function: cell skeleton and tansportion 3. synapses Synapses are the sites where contact occurs between neurons or between neurons and other effect cell(eg. muscles or gland cells). A chemical synapse consists of a presynaptic element, a synaptic cleft and a postsynaptic element. 4. nerve fiber Nerve fibers are composed of axons enveloped by neuroglia cells (sheath cell), including myelinated and unmyelinated nerve fibers. 5. blood –brain barrier(BBB) It is a physiologic barrier that restricts indiscriminate access of certain substances in the blood stream to the brain. It consists of continous capillary, basement membrane, and astrocyte end-feet(foot processes). II. Fill in the blanks 1. neurons, neuroglial cells 2. cell body/soma, processes 3. axon, dendrite 4. soma, dendrite, axon, axon hillock 5. a presynaptic element, a synaptic cleft, a postsynaptic element 6. astrocytes, oligodendrocytes, microglia, ependymal cells 7. axon, myelin sheath, neurolemma 8. Schwann cells, oligodendrocytes 9. dermis 10. sarcolemma III. Questions - 40 - 1. Describe the structure of the neuron soma ①membrane receiving stimuli and conducting nerve impulses. ②nucleus: large and spherical with a prominent nucleolus. ③perikaryon (cytoplasm) Nissl’s body Location: in soma and dendrite L.M. basophilic granular areas E.M. are RER and free ribosome, Golgi complex Function: synthesize proteins neurofibrils Location: in soma, axon and dendrite L.M. dark brown filaments E.M. neurofilaments Function:cell skeleton and tansportion 2. Describe the structure of myelinated nerve fiber in peripheral nervous system. Axon: center Schwann cells: myelin sheath neurolemma Ranvier’s node Internode IV. Choose the correct answers for each question. 1.A 2.C 3.D 4.B 5.D 6.E 7.D 8.C 9.E 10.C V. Choose the true or false by “T” & “F” 1. F 2. F 3. T 4. F 5. T 6. T 7. F 8. F Cui hong-mei - 41 - CIRCULATORY SYSTEM I. Definitions 1. continuous capillary 2. fenestrated capillary 3. sinusoidal capillary 4. Purkinje cell Ⅱ. Fill in the blanks 1. According to the circulating fluid in the tubes, blood or lymph, the circulatory system is divided into and two major components. 2. All organs of the cardiovascular system except for the capillaries share common structural features. Their walls are generally composed of three concentric tunics: , and . 3. Under the electron microscope, capillaries can be classified as , and . 4. The tunica media of the medium-sized arteries is prominent in , hence they are termed . 5. The tunica media of large arteries, which is the thickest layer, consists mainly of , hence they are termed . 6. The wall of the heart consists of three main layers: and . 7. The endocardium of the heart consists of three layers: and of the pericardium, . 9. Continuous capillaries are present in many tissues, including and , . 8. The epicardium is the which is covered by , . 10. Fenestrated capillaries are present in __________, ______________ and _________________ . - 42 - , 11. Sinusoidal capillaries can be found in and , , . Ⅲ. Questions 1. Describe the classifications and structures of the capillaries under the electron microscope. 2. Describe the structures of medium-sized arteries. 3. Describe the structure of the heart wall. Ⅳ. Choose the correct answers for each question. 1. Which one is termed muscular artery ( ) A. large artery B. medium-sized artery C. aorta D. common carotid artery E. pulmonary artery 2. Which one is termed elastic artery ( ) A. small artery B. medium-sized artery C. femoral artery D. large artery E. renal artery 3. The fenestrae or pores of the fenestrated capillaries lie in ( ) A. the gaps between epithelial cells B. the endothelial cytoplasm without nucleus C. basal lamina D. endothelial nucleus E. the free surface of endothelium 4. Which one of the following descriptions about continuous capillaries is true? ( ) - 43 - A. A small number of plasmalemmal vesicles can be found in the endothelial cytoplasm, tight junctions occur to seal the vessel wall, and the basal lamina is continuous. B. A large number of plasmalemmal vesicles can be found in the endothelial cytoplasm, tight junctions occur to seal the vessel wall, and the basal lamina is continuous. C. A large number of plasmalemmal vesicles can be found in the endothelial cytoplasm, intercellular gap is wide, and the basal lamina is continuous. D. A large number of plasmalemmal vesicles can be found in the endothelial cytoplasm, tight junctions occur to seal the vessel wall, and the basal lamina is discontinuous. E. A small number of plasmalemmal vesicles can be found in the endothelial cytoplasm, intercellular gap is wide, and the basal lamina is continuous. 5. Which one of the following descriptions about fenestrated capillaries is true? A. A small number of plasmalemmal vesicles can be found in the endothelial cytoplasm, endothelia have connections, and the basal lamina is continuous. B. A large number of plasmalemmal vesicles can be found in the endothelial cytoplasm, endothelia have connections, and the basal lamina is continuous. C. A small number of plasmalemmal vesicles can be found in the endothelial cytoplasm, intercellular gap is wide, and the basal lamina is continuous. D. A small number of plasmalemmal vesicles can be found in the endothelial cytoplasm, endothelia have connections, and the basal lamina is discontinuous. - 44 - E. A large number of plasmalemmal vesicles can be found in the endothelial cytoplasm, no space among endothlial cell 6. The tunica media of medium-sized arteries is predominantly composed of ( ) A. collagen fiber B. smooth muscle fiber C. elastic fiber D. reticular fiber E. elastic membrane 7. Most of the continuous capillaries are present in( ) A. central nervous system B. gastric mucosa C. endocrine glands D. liver, spleen E. glomerulus 8. Most of the fenestrated capillaries are present in( ) A. connective tissue B. gastric mucosa C. muscle tissue D. lung E. cerebrum 9. Most of the sinusoidal capillaries are present in( ) A. lung B. gastric mucosa C. muscle tissue D. liver, spleen E. glomerulus 10. In which one, the tunica adventitia is as thick as the tunica media?( A. large arteries - 45 - ) B. large veins C. medium-sized arteries D. medium-size veins E. heart Ⅴ. Choose the true or false by “T” & “F” 1. All organs of the cardiovascular system have three layers.( ) 2. The lymph vascular system drains the tissue fluid from the organs and tissues and unidirectionally carries it to the blood.( ) 3. There are clearly-defined limits existing between different groups of arteries.( ) 4. The large arteries belong to the elastic arteries because they contain a large number of elastic membranes in their walls.( ) 5. The tunica media of large artery consists mainly of 40-70 concentrically-arranged elastic membranes.( ) 6. In the continuous capillaries, a large number of plasmalemmal vesicles can be found in the endothelial cytoplasm, tight junctions occur to seal the vessel wall, and the basal lamina is continuous.( ) 7. In general, the sinusoidal capillaries are more irregular in shape and much wider in diameter than those of ordinary capillaries. Wide gaps are present between endothelial cells. The basal lamina is incomplete. ( ) 8. The boundaries between the three tunics of a vein’s wall are clear.( ANSWERS Ⅰ. Definitions 1. continuous capillary Continuous capillaries are present in many tissues including the skin, connective tissues, striated and smooth muscles, lungs and brain. Their - 46 - ) wall consists of a continuous layer of endothelium. A large number of plasmalemmal vesicles can be found in the cytoplasm along both The luminal and basal surfaces. A continuous basal lamina surrounds the endothelium of the capillaries. 2. fenestrated capillary Fenestrated capillaries are present in the gastric mucosa, some endocrine glands and glomerulus. Fenestrated capillaries have fenestrae or pores within the attenuated endothelial cytoplasm, the pores are usually closed by a diaphragm, and on the basal side of endothelium the basal lamina is continuous across the pores. 3. sinusoidal capillary Sinusoidal capillaries can be found in the liver, spleen, bone marrow and in certain endocrine glands. Their lumina are more irregular in shape and much wider in diameter than those of ordinary capillaries. Wild gaps are present between endothelial cells. The basal lamina is incomplete. 4. Purkinje cell Purkinje cells are mainly present in the subendocardial layer. Purkinje cells are both broader and shorter than ordinary cardiac muscle fibers. They are rich in sarcoplasm but only a small number of myofibrils are distributed in the peripheral part of the cells, large amounts of glycogen are to be found in their cytoplasm and a spherical nucleus is situated in the cell centers, sometimes two nuclei can be found in a Purkinje cell. In light microscopic examinations of H&E preparations, they stain pale. Impulses are conducted through the Purkinje cells to the working myocardial cells. The Purkinjie cells conduct impulses much faster than ordinary cardiac muscle fibres. Ⅱ. Fill the blanks 1. blood circulatory (or cardiovascular system), lymph vascular system 2. tunica intima, tunica media, tunica adventitia - 47 - 3. continuous capillaries, fenestrated capillaries, sinusoidal capillaries 4. smooth muscle, muscular arteries 5. 40-70 concentrically-arranged elastic membranes, elastic arteries 6. endocardium, myocardium, epicardium 7. endothelium, subendothelial layer, subendocardial layer 8. visceral layer, mesothelium 9. skin, connective tissues, striated and smooth muscles( or lungs, or brain) 10. gastric mucosa, some endocrine glands, glomerulus 11. liver, spleen, bone marrow, some certain endocrine glands Ⅲ. Questions 1. Describe the classifications and structures of the capillaries under the electron microscope. Under the electron microscope, capillaries can be classified as three types: 1) Continuous capillaries are present in many tissues including the skin, connective tissues,striated and smooth muscles,lungs and brain. Their wall consists of a continuous layer of endothelium. A large number of plasmalemmal vesicles can be found in the cytoplasm along both the luminal and basal surfaces. A continuous basal lamina surrounds the endothelium of the capillaries. 2) Fenestrated capillaries are present in the gastric mucosa, some endocrine glands and glomerulus. Fenestrated capillaries have fenestrae or pores within the attenuated endothelial cytoplasm, the pores are usually closed by a diaphragm, and on the basal side of endothelium the basal lamina is continuous across the pores. 3) Sinusoidal capillaries can be found in the liver, spleen, bone marrow and in certain endocrine glands. Their lumina are more irregular in shape and much wider in diameter than those of ordinary capillaries. Wild gaps are present between endothelial cells. The basal lamina is incomplete. - 48 - 2. Describe the structures of medium-sized arteries. The wall of the medium-sized arteries is composed of three layers: 1) Tunica intima, the tunica intima also consists of three layers: an endothelium, a subendothelial layer and an internal elastic membrane. 2) Tunica media, the tunica media is predominantly composed of 10-40 layers of concentrically-arranged smooth muscle cells. Between the layers of smooth muscle, small amounts of collagenous fibers and elastic fibers can be found. 3). Tunica adventitia, it is composed of connective tissue. A definite external elastic membrane is situated between the tunica media and the tunica adventitia. 3. Describe the structure of the heart wall. The heart wall’s tunica intima, tunica media, tunica adventitia are termed endocardium, myocardium and epicardium, respectively. 1). Endocardium: the endocardium consists of three layers: the endothelium, the subendothelial layer and the subendocardial layer. The subendocardial layer contains Purkinje fibers. 2). Myocardium: it is mainly composed of cardiac muscle. Between the muscle fibers there are small amount of loose connective tissue and capillaries. 3). Epicardium: the epicardium is the visceral layer of the pericardium which covers the exterior of the heart. It is a serous membrane formed by simple squamous epithelium on its surface and a thin layer of loose connective tissue beneath. Ⅳ. Choose the correct answers for each question. 1.B 2.D 3.B 4.B 5.A 6.B 7.A 8.B 9.D 10.C Ⅴ. Choose the true or false by “T”&”F” 1.F 2.T 3.F 4.T 5.T 6.T 7.T 8. F Wang jun-yan - 49 - BLOOD AND HAEMOPOIESIS Ⅰ. Definitions 1. erythrocyte 2. neutrophil 3. platelet 4. reticulocyte II. Fill in the blanks 1. Blood is a specialized form of and , consisting of . 2. The blood cells include , , and 3. Mature erythrocytes in mammalian have no . , no In human, they are shaped like . . 4. The cytoplasm of erythrocytes mainly contains a large amount of ________, the normal value of which is about in male and in female. 5. Reticulocytes are the erythrocytes which are recently released by bone marrow into the bloodstream containing small amounts of . 6. On the basis of specific granules in the cytoplasm, the leukocytes may be classified into two categories: and . 7. Based on the different specific granules in their cytoplasm, granulocytes consist of , , and agranulocytes include , and 8. Blood platelets are the fragments of no ; while . in bone marrow , and have . Each platelet has two regions: a central deeply basophilic and a peripheral pale homogeneous . 9. The maturation process of blood cells can be divided into three stages: , , and 10. During the process of haemopoiesis, change into any type of blood cell. - 50 - . has the ability to III. Questions 1. Describe the categories and normal value of blood cells. 2. Describe the structural features of five types of leukocytes under light and electron microscope. 3. Summarize the major changes in the maturation course of the erythrocytic series cells. IV. Choose the correct answer for each question. 1. Serum is different from plasma in that it is devoid of ( ) A. fibrinogen B. erythrocytes C. all proteins D. hormones E. leukocytes 2. Normal concentration of leukocytes in humans is( ) A. (4.2~5.5)×1012/L B. (4~10)×109/L C. (3.5~5)×1012/L D. (105~135)×1012/L E. (100~400)×109/L 3. Which of the following statements is NOT true of mature erythrocytes? ( ) A. biconcave discs in shape B. 7.5~8.5 m in diameter C. a nucleus with two lobes D. rich in hemoglobin E. have no organelles 4. Reticulum in reticulocytes is remnants of the ( A. nucleus - 51 - ) B. lysosomes C. mitochondria D. endoplasmic reticulum E. ribosomes 5. The basis of classification of leukocytes is the ( ) A. cell size B. morphology of nucleus C. specific granules D. non-specific granules E. phagocytizing capacity 6. Which of the following statements is NOT true of neutrophils? ( ) A. Account for 50%-70% of the total circulating leukocytes B. They are agranulocytes C. They have a polymorphous nucleus with 2~5 lobes D. They contain specific granules and azurophilic granules E. Neutrophilic granules contain bactericidal phagocytins 7. Which of the following blood cells is increased in number after active invasion of bacteria? ( ) A. neutrophils B. monocytes C. lymphocytes D. erythrocytes E. eosinophils 8. The cells phagocytosing antigen-antibody complex are ( A. monocytes B. neutrophils C. platelets - 52 - ) D. erythrocytes E. eosinophils 9. Which type of cells is associated with the allergic reaction and serves as an anticoagulant? ( ) A. platelets B. monocytes C. neutrophils D. basophils E. eosinophils 10. Peroxidase is NOT present in ( ) A. neutrophils B. monocytes C. lymphocytes D. basophilis E. eosinophils 11. Which of following statements is NOT true of basophils? ( ) A. Constitute about 3%-8% of the leukocyte population B. Contain large, dark blue-staining granules with Wright stain C. Specific granules contain heparin and histamine D. Nucleus may be not clear because of overlap with granules E. May be associated with allergic reaction 12. Which of following statements does NOT refer to monocytes? ( ) A. account for about 3%-8% of the leukocyte population B. They are the largest cells in blood C. Azurophilic granules contain heparin and histamine D. have a horseshoe or kidney-shaped nucleus E. differentiate into macrophages when leaving out of blood vessels 13. Which of following statements is NOT true of platelets? ( A. normal counts range (150-300)×109/L - 53 - ) B. They are fragments of megakaryocytes C. have a hyalomere and a granulomere D. The function is to stop bleeding E. associated with allergic reaction 14. Histamine in blood is mainly released by the ( ) A. macrophages B. eosinophils C. mast cells D. basophils E. neutrophils 15. During parasite infection, the cells that are increased in number are ( A. monocytes B. lymphocytes C. neutrophils D. eosinophils E. basophils 16. The earliest hematopoietic cells are derived from the ( A. yolk sac B. amniotic cavity C. liver D. spleen E. bone marrow 17. The azurophilic granules actually are the ( A. chromosomes B. lysosomes C. ribosomes D. phagosomes E. pinosomes - 54 - ) ) ) 18. Platelets would LEAST likely adhere to which of the following structures? ( ) A. collagen B. other platelets C. microfibrils associated with elastin D. normal endothelium E. damaged endothelium V. Choose the true or false by “T”&“F” 1. Blood is a specialized form of connective tissue proper, consisting of blood cells and plasma. ( ) 2. For examining the morphology of blood cells, blood smear is usually used and stained with Wright or Giemsa stain. ( ) 3. The special shape of erythrocytes facilitates gaseous exchange. ( ) 4. The biconcave shape of red blood cells is maintained by microtubules and microfilaments. ( ) 5. The young erythrocytes in the bloodstream often containing ribosomes are termed reticulocytes.( ) 6. According to having granules in their cytoplasm or not, leukocytes are classified into two groups: granulocytes and agranulocytes. ( ) 7. The cytoplasm of basophils has specific granules containing heparin and histaminase.( ) 8. Monocytes are capable of crossing capillary walls, and differentiate into lymphocytes. ( ) 9. All cells in blood are end cells, which no longer divide. ( ) 10. Erythrocytes functions within blood vessels, while leukocytes function mainly outside the vessels. ( ) 11. Mature erythrocyte has no nucleus, but has some organelles. ( - 55 - ) ANSWERS Ⅰ. Definitions 1. erythrocyte The erythrocytes of mammals have no nucleus and in humans they are biconcave discs 7-8 m in diameter. The cytoplasm mainly contains a large amount of haemoglobin (Hb). In a smear, RBC stains red. The periphery of RBC is redder than the center of it. The normal concentration of erythrocytes in blood is approximately 4.5-5 million per cubic millimetre in women and 5 million per cubic millimetre in men. The chief function of RBC is to transport O2 from the lungs to the tissue and transport CO2 from the tissue to the lungs. 2. neutrophil Neutrophils are the most numerous of the leukocytes in human blood and constitute 60-70% of the leukocyte population. They are about 12m in diameter, with a highly polymorphous nucleus, consisting of 2-5 sausage-shaped lobes, interlinked by a fine thread of chromatin. The cytoplasm is filled with fine granules, the majority of which are neutrophilic. Under the electron microscope, the granules present in neutrophils are seen to be surrounded by a membrane and can be separated into two types: azurophilic and specific. Azurophilic granules contain lysosomal enzymes and peroxidase, while specific granules contain alkalin phosphatase and bactericidal phagocytins. Neutrophils are actively mobile and phagocytic. They are one of the most important lines of defence against the bacterial infection. 3. platelet Platelets are 150~300 thousand per cubic millimetre of blood. They are derived from megakaryocytes of bone marrow, and are enucleated, disc-like cell fragments 2-5m in diameter. In stained blood smears, they often appear in clumps, irregular in shape. Each platelet has two regions: a - 56 - deeply basophilic granular zone (the granulomere),usually centrally-located, and a pale homogeneous peripheral zone (the hyalomere). Platelets are related to the functions of hemostasis and coagulation. 4. reticulocyte The young erythrocytes which are recently released by bone marrow into the bloodstream often contain small amounts of residual ribosomal RNA. Such erythrocytes are termed reticulocytes. They are larger than erythrocytes and their cytoplasm contains basophilic dots or delicate network.These structures indicate they are able to synthesis Hb. The normal value of them is less than 1% of the total RBC. The percentage of reticulocytes may indicate the functional states of the bone marrow. II. Fill in the blanks 1. connective tissue, blood cells(formed elements), blood plasma. 2. erythrocytes(RBCs), leukocytes(WBCs), platelets. 3. nuclei, organelles, biconcave discs. 4. haemoglobin (Hb), 12~15 g/100ml,10.5~14g/ 100ml. 5. young, residual ribosome. 6. granulocytes, agranulocytes. 7. neutrophils, eosinophils, basophils, lymphocytes, monocytes. 8. megakaryocytes, nuclei, granulomere, hyalomere. 9. the problast stage, the blast stage, the mature stage. 10. haemocytoblast. III. Questions - 57 - 1. Describe the categories and normal value of blood cells. Erythrocyte male: 4-5 million/ mm3 female: 4.5-5 million / mm3 s granulocytes Leukocytes 5-10 thousand/mm3 agranulocyte Platelets neutrophils 60-70% eosinophils 1-3% basophils 0-1% lymphocytes 20-30% monocytes 3-8% s 150-300 thousand/mm3 2. Describe the structural features of five types of leukocytes under light and electron microscope. (a) Neutrophils Neutrophils are the most numerous of the leukocytes in human blood and constitute 60-70% of the leukocyte population. They are about 12m in diameter, with a highly polymorphous nucleus, consisting of 2-5 sausage-shaped lobes, interlinked by a fine thread of chromatin. The cytoplasm is filled with fine granules, the majority of which are neutrophilic. Under the electron microscope, the granules present in neutronphils are seen to be surrounded by a membrane and can be separated into two types: azurophilic and specific. Azurophilic granules contain lysosomal enzymes and peroxidase, while specific granules contain alkalin phosphatase and bactericidal phagocytins. (b) Eosinophils Eosinophils constitute about 1-3% of the leukocyte population and measure 10~12m in diameter. The nucleus usually has two lobes, and the cytoplasm is packed with coarse acidophilic granules. These gran- ules are surrounded by a unit membrane and contain acid phosphatase and histaminase. - 58 - (c) Basophils Basophils number only 0-1% of the blood leukocytes. They measure about 12m in diameter and have an irregular large nucleus which is generally S-shaped. The cytoplasm contains large, dark blue-staining granules containing heparin and histamine. Often the granules obscure the nucleus and stain metachromatically. Examination with an electron microscope shows that the granules are very electron-dense and bounded by a membrane. (d) Lymphocytes Lymphocytes constitute about 20~30% of the total leukocyte population. They range in diameter from 7~12m, but the smaller lymphocytes with a diameter ranging between 6-8m are in the majority in circulating blood, while there is only a small percentage of medium-sized and large lymphocytes. The smaller lymphocyte has a spherical nucleus, sometimes with an indentation. Its chromatin is condensed and appears as coarse clumps, so that the nucleus is intensely stained in the usual preparations. The cytoplasm of the small lymphocyte is scanty and appears as a thin rim in blood smears. It is slightly basophilic, assuming a light-blue colour in stained smears. Azurophilic granules are present in lymphocytes. The cytoplasm is lacking in organelles but contains many free ribosomes and polyribosomes. (e) Monocytes Monocytes with a diameter varying from 14~20m constitute only 3-8% of the leukocytes of normal blood. Their nuclei are oval, horseshoe, or kidney- shaped and is generally eccentrically placed. The nuclei do not stain as deeply as that of the lymphocytes. The cytoplasm is basophilic and shows bluish-gray colour in stained smears. Azurophilic granules are also present in this cell-type, which are in fact lysosomes under electron microscope. The cytoplasm also contains some rough endo- 59 - plasmic reticulum but fewer free ribosomes than are found in lymphocytes. 3. Summarize the major changes in the maturation course of the erythrocytic series cells. (a) the cell volume decreases; (b) nucleoli diminish in size until they become invisible under the light microscope; (c) the diameter of the nucleus decreases, and the chromatin becomes increasingly more dense until the nucleus presents a pyknotic appearance and is finally extruded from the cell; (d) the number of basophilic polyribosomes decreases and the amount of acidophilic haemoglobin increases within the cytoplasm; (e) the quantity of mitochondria and other organelles diminishes. IV. Choose the correct answer for each question. 1. A 10. C 2. B 3. C 11. A 4. E 12. C 5. C 13. E 6. B 14. D 7. A 15. D 8. E 9. D 16. A 17. B 18. D V. Choose the true or false by “T”&“F” 1. F 2. T 3. T 4. F 5. T 6. F 7. F 8. F 9. F 10. T 11. F Hu zhi-mei - 60 - LYMPHATIC ORGANS Ⅰ. Definitions 1. lymphoid nodule 2. blood-thymus barrier 3. splenic corpuscle 4. recirculation of lymphocyte Ⅱ. Fill in the blanks 1. Lymphocytes are widely distributed, according to their different developments, structures and immune functions; they can be classified as , and . 2. In the lymphatic tissue, comprises a framework, the meshes of which are filled with and other immune cells. 3. According to the constitutions and functions, lymphatic organs can be classified as , including thymus and bone marrow, and , including lymph nodes, spleen and tonsils. 4. The lymphocytes in the thymus are also termed distribute in , mainly , occuping 85%~90% of the thymus cells in the cortex. 5. Blood-thymus barrier is composed of _____________, ____________, ____________, ___________and . 6. Diffuse lymphatic tissue lies in the deep portion of the cortex in lymph nodes, most lymphocytes in this zone are termed thymus dependent area or , so this area is . 7. Medulla lies in the deep portion of the lymph nodes, it is composed of and 8. . is the largest peripheral lymphatic organs, which is on the pathway of circulation system. 9. The parenchyma of the spleen is divided into three parts: ______________ and . - 61 - , 10. Red pulp occupies most space of the parenchyma of the spleen, it is composed of and 11. The functions of the spleen are . , and . Ⅲ. Questions 1. Describe the structures of the lymph nodes. 2. Describe the structures of the spleen. Ⅳ. Choose the correct answers for each question 1. Which description about the lymphoid nodules is WRONG? ( ) A. They are also termed lymphoid follicles B. They are mainly composed of dense B-lymphocytes C.Tthey are spheroid or ovoid D. Sometimes have a germinal centre and a cap E. They have prominent interdigitating cells 2. The cortex of the lymph nodes does NOT have ( ) A. lymphoid nodule B. paracortical zone C. postcapillary venules D. cortical lymphatic sinuses E. capsule 3. T-lymphocytes of the lymph nodes are mainly distribute in ( A. surperfacial cortex B. paracortical zone C. medullary cords D. lymph sinus E. germinal centre 4. The thymus-dependent region of the spleen is ( A. splenic corpuscle B. splenic cord - 62 - ) ) C. white pulp D. peri-arterial lymphatic sheath E. marginal zone 5. The red pulp of the spleen is composed of ( ) A. splenic sinuses and splenic corpuscles B. splenic cords and peri-arterial lymphatic sheath C. splenic cords and splenic sinuses D. splenic corpuscles and marginal zone E. splenic sinuses and marginal zone 6. Which discription of the marginal zone of spleen is WRONG? ( ) A. lies between the white pulp and the red pulp B. consists of T-lymphocytes, B-lymphocytes, macrophages and erythrocytes C. It is an important pathway which transports lymphocytes from blood to the spleen D. plays a major role in capturing antigen and initiates an immune response E. belongs to the white pulp of the spleen 7. When stimulated by an antigen, which part of the lymph nodes forms the lymphoid nodule ( ) A. superfacial cortex B. paracortical zone C. superfacial cortex and paracortical zone D. medullary cords E. lymphatic sinuses 8. The major cell which the lymph nodes filter lymph and detach antigens are ( ) A. the endothelial cells B. reticular cells - 63 - C. B-lymphocytes D. plasma cells E. macrophages 9. The characteristic structure of the thymus is ( ) A. splenic corpuscle B. thymic corpuscle C. white pulp D. peri-arterial lymphatic sheath E. trabecula 10. Which one does NOT compose the blood-thymus barrier ( ) A. a continuous capillary endothelial layer and the basement membrane of the endothelial layer B. the tight junction between the thymocytes C. a peri-vessel space containing some macrophages D. a continuous epithelial reticular cells layer E. the basement membrane of the epithelial reticular cells Ⅴ. Choose the true or false by “T”&”F” 1. The major lymphatic organs are the thymus, lymph nodes, spleen and tonsils.( ) 2. The spleen is treated as the central (or primary) lymphatic organ.( ) 3. Peripheral (or secondary) lymphatic organs develop earlier than the central lymphatic organ.( ) 4. In the cortex of thymus, small lymphocytes, sometimes termed thymocytes, mainly predominate.( ) 5. In the lymph nodes, the T-lymphocytes mainly distribute in the superficial cortex.( ) 6. The germinal centre of the lymphoid nodule is the proliferation site for B-lymphocytes.( ) - 64 - 7. The primary function of the lymph nodes is the production of lymphocytes which give rise to the immune response.( ) 8. The white pulp of the spleen contains numerous postcapillary venules.( ) 9. In well-developed splenic corpuscles, a cap, dark zone and light zone can be seen.( ) 10. In the spleen, the marginal zone belongs to the white pulp.( ) ANSWERS Ⅰ. Definitions 1. lymphoid nodule Lymphoid nodules are composed of large number of densely aggregated lymphocytes, which is mainly composed of B lymphocytes. When stimulated by an antigen, a lymphatic nodule responds by forming a germinal centre, which is composed of a dark zone, a light zone and a cap. 2. blood-thymus barrier The blood-thymus barrier is formed by a continuous capillary endothelial layer, the basement membrane of the endothelial layer, a peri-vessel space containing some macrophages, the basal lamina of the epithelial reticular cells and a continuous epithelial reticular cell-layer. 3. splenic corpuscle splenic corpuscles are typical lymphatic nodules, composed mainly of B-lymphocytes. In well-developed splenic corpuscles, a cap, dark zone and light zone can also be seen. 4. recirculation of lymphocyte Lymphocytes in the bloodstream, produced originally in the lymphoid tissue or organs and carried by the circulation of blood through the - 65 - lymphatic vessels, re-enter the lymphoid tissue or organs by crossing the walls of postcapillary venules. Ⅱ. Fill in the blanks 1. T-lymphocytes, B-lymphocytes, NK cells 2. reticular tissue, lymphocytes 3. central lymphatic organ, peripheral lymphatic organ 4. thymocytes, thymic cortex 5. a continuous capillary endothelial layer, the basement membrane of the endothelial layer, a peri-vessel space containing some macrophages, the basement membrane of the epithelial reticular cells , a continuous epithelial reticular cell-layer 6. T-lymphocytes, paracortical zone 7. medullary cords, medullary sinuses 8. spleen 9. white pulp, marginal zone, red pulp 10. splenic cords, splenic sinuses 11. blood filter, immunological defence, production of blood cells, blood storage Ⅲ. Questions 1. Describe the structures of the lymph nodes. Lymph nodes are covered by a definite capsule of connective tissue, which is continuous with a number of septa or trabeculae extending into the parenchyma of the organs. The parenchyma is divided into the cortex and medulla. The cortex is located beneath the capsule, it is composed of superfacial cortex, paracortical zone and cortical lymphatic sinuses. Superfacial cortex is mainly composed of lymphoid nodules, is the proliferation site for B-lymphocytes. The paracortical zone lies in the deep portion of the cortex, filled with diffuse lymphatic tissue, and mainly are - 66 - T-lymphocytes. This zone characteristically contains numerous postcapillary venules, they are critical to lymphocyte recirculation. Cortical lymphatic sinuses are located among the capsule, trabeculae and lymphatic nodules, divided into sub-capsular sinuses and peritrabecular sinuses. The medulla is in the deep part of the lymph nodes, composed of medullarycords and medullary sinuses. 2. Describe the structures of the spleen. Spleen is the largest peripheral lymphatic organs, on the pathway of circulation system. The spleen is surrounded by a connective tissue capsule, which itself is covered by a serous membrane, the peritoneum. The parenchyma of the spleen is divided into three parts: white pulp, marginal zone and red pulp. The white pulp consists of two kinds of structure: peri-arterial lymphatic sheath and splenic corpuscles. A layer of dense lymphatic tissue encircling an artery forms a peri-arterial lymphatic sheath. The small artery, known as the central artery, is located in the centre of the lymphatic sheath. The cells present within the sheath are predominantly T-lymphocytes associated with macrophages and interdigitating cells. This structure is equivalent to the thymus-dependent region. The lymphatic nodules in the white pulp is also termed splenic corpuscles. At the intervals of the white pulp, the lymphatic tissue surrounding the arteriole thicken into ovoid masses, the splenic corpuscles. These locate beside the peri-arterial lymphatic sheath, have a germinal centre in their centre. These are the response when B-lymphocytes are activated. The marginal zone located between the white pulp and the red pulp, the main lymphocytes are B-lymphocytes, and have many macrophages and hemocytes. The marginal zone harbours an abundance of blood - 67 - antigens and thus plays a major role in the spleen’s immunological activity, as they can initiate an immune response. The red pulp occupies most space of the parenchyma of the spleen, it is composed of splenic cords and splenic sinuses. The type of lymphocytes in the splenic cords is B-lymphocytes, in the splenic sinuses is blood sinusoid. Ⅳ. Choose the correct answers for each question 1. E 2. E 3. B 4. D 5. C 6. E 7. A 8. E 9. B 10. B Ⅴ. Choose the true or false by “T”&”F” 1.T 2.F 3.F 4.T 5.F 6.T 7.T 8.F 9.T 10.F Wang jun-yan - 68 - DIGESTIVE TRACT Ⅰ. Definitions 1. plica 2. intestinal villus 3. chief cell 4. parietal cell Ⅱ. Fill in the blanks 1. From the inside to the outside the wall of the digestive tract (esophagus, stomach, small intestine and large intestine) can be divided into four , layers: , and . 2. The mucosa is the most important layer of the digestive tract, it can be subdivided into , and . 3. The adventitia of oesophagus is composed of connective tissue, which is called ; while the outer layer of stomach is formed by , which consists of 4. Plicae are formed by and . and , which both protrude into the lumen of digestive tract. 5. Gastric glands can be divided into and , . 6. Foundic glands consist of five kinds of cells, they are: , 7. , and . can produce hydrochloric acid, while can secrete pepsinogen. 8. Three structures that can expand the surface area of the small intestine, they are: , and . 9. Intestinal villi are finger-like projections, which consist of a core of , and are covered by - 69 - . 10. In the lamina propria of intestinal villi, there are three structures relating to the absorption, they are: and , . 11. There are a lot of glands, which are located in the submucosa of the duodenum. Ⅲ. Questions 1. Describe the structures and functions of intestinal villi . 2. Describe the general structure of digestive tract . 3. Describe the organizational structure of stomach wall . Ⅳ. Choose the correct answers for each question 1. Which of the following statements is true about plicae . ( ) A. Both mucosa and submucosa protrude into the lumen of the digestive tract. B. Submucosa together with muscularis externa protrude into the lumen of the digestive tract. C. Epithelium and lamina propria protrude into the lumen of the digestive tract. D. Only mucosa protrudes into the lumen of the digestive tract. 2. Intestinal villi are composed of ( ) A. absorptive cells and goblet cells B. simple columnar epithelium and lamina propria C. absorptive cells and endocrine cells D. mucosa and submucosa E. submucosa and muscularis externa 3. Which of the following cells is NOT included in the foundic glands ( ) A. chief cells B. parietal cells C. Paneth cells - 70 - D. endocrine cells E. mucous neck cells 4. The large intestinal glands are composed of all of the following cells EXCEPT ( ) A. absorptive cells B. goblet cells C. endocrine cells D. Paneth cells E. undifferentiated cells 5. Which of the following descriptions is NOT true about chief cell ( ) A. The cell is columnar in shape and the cytoplasm is stained basophilic. B. There are many zymogen granules in the cytoplasm. C. There are abundant rough endoplasmic reticulum in the cytoplasm. D. Membranous granules exist in the cytoplasm. E. It can secrete pepsin. 6. Which of the following cells can secrete hydrochloric acid ( ) A. parietal cells B. chief cells C. endocrine cells D. Paneth cells E. mucous neck cells 7. Which of the following statements is NOT true about absorptive cell ( ) A. The cell is columnar in shape. B. Numerous closely-packed cilia at the free surface of the cell form a striated border. C. The nucleus is ovoid and located toward the base. D. A layer of glycoprotein filaments covers the plasma membranes of microvilli. - 71 - E. There are abundant smooth endoplasmic reticulum in the cytoplasm. 8. Which of the following statements is NOT true about esophagus ( ) A. The epithelium is composed of non-keratinised stratified squamous epithelium. B. Mucus-secreting esophageal glands are present in the submucosa. C. The adventitia is a serous membrane. D. The muscularis externa is formed by both skeletal muscle and smooth muscle in the middle third of portion. E. There is only one layer in the muscularis mucosae. 9. Which of the following structures does NOT have goblet cells? A. small intestinal columnar epithelium B. large intestinal columnar epithelium C. small intestinal gland D. large intestinal gland E. gastric epithelium 10. The wall of the digestive tract is composed of ( ) A. mucosa ,submucosa, muscularis externa and adventitia B. mucosa ,submucosa, muscularis externa and serosa C. mucosa ,submucosa, muscularis externa and fibrosa D. mucosa ,submucosa and adventitia E. tunica intima, tunica media and tunica adventitia Ⅴ. Choose the true or false by “T” & “F” 1. Plicae are composed of both epithelium and lamina propria. ( ) 2. Parietal cells are large deeply basophilic cells , which are pyramidal or spherical in shape. ( ) 3. The lamina propria of intestinal villi contains the central lacteals, fenestrated capillaries and scattered skeletal muscle cells. ( 4. The wall of the digestive tract can be divided into four layers, mucosa ,submucosa, muscularis and adventitia. ( - 72 - ) ) 5. The gastric glands are composed of chief cells, parietal cells, Paneth cells, stem cells and mucous neck cells. ( ) 6. Numerous goblet cells exist in the epithelium of stomach. ( 7. Chief cells can secrete pepsinogen. ( ) ) 8. The epithelium of the esophagus is simple columnar epithelium. ( ) 9. The muscularis externa of the oral cavity , pharynx, upper esophagus and the anus is formed by skeletal muscle. ( ) 10. The adventitia of stomach is serous membrane. ( ) ANSWERS Ⅰ. Definitions 1. plica Plicae are composed of both mucosa and submucosa; They can expand the surface area and are good for absorption. 2. intestinal villus Intestinal villi are finger-like projections,which consist of a core of lamina propria covered by simple columnar epithelium. The lamina propria is composed of loose connective tissue. The central lacteal, fenestrated capillary, scattered smooth muscle cells which are found in the cores of the villi are associated with the small intestine’s absorptive function. 3. chief cell Chief cells are columnar in shape. The nuclei lie in the basal half of the cells.Large secretory granules containing pepsinogen, are found in the apical cytoplasm.The basal cytoplasm is strongly basophilic.Under the electron microscope, abundant rough endoplasmic reticulum, Golgi complex and mitochondria are present in the cytoplasm . Chief cells can secrete pepsinogen. - 73 - 4. parietal cell Parietal cells are large deeply eosinophilic cells , which are pyramidal or spherical in shape. The nuclei are centrally-placed. Under the electron microscope, there are abundant intracellular secretory canaliculus and tubulovesicular system in the cytoplasm. Parietal cells can produce hydrochloric acid and intrinsic factor. Ⅱ. Fill the blanks 1. mucosa , submucosa, muscularis and adventitia 2. epithelium , lamina propria , muscularis mucosa 3. fibrosa, serosa, connective tissue, mesothelium 4. mucosa, submucosa 5. cardiac glands, pyloric glands and gastric glands 6. chief cells, parietal cells, mucous neck cells, endocrine cells, undifferentiated cells 7. Parietal cells, chief cells 8. circular Plicae, intestinal villi, microvilli 9. lamina propria, simple columnar epithelium 10. central lacteal, fenestrated capillary, scattered smooth muscle 11. duodenal glands Ⅲ. Questions 1. Describe the structure and function of intestinal villi Intestinal villi are finger-like projections,which consist of a core of lamina propria covered by simple columnar epithelium.The lamina propria is composed of loose connective tissue. The central lacteal, fenestrated capillary, scattered smooth muscle cells which are found in the cores of the villi are associated with the small intestine’s absorptive function. 2. Describe the general structure of digestive tract - 74 - The wall of the digestive tract can be divided into four layers: mucosa , submucosa, muscularis externa and adventitia. (1) The mucosa is composed of epithelium ,lamina propria and muscularis mucosa.The stratified squamous epithelium of the oral cavity, pharynx,esophagus and anus is capable of withstanding abrasion.Tall columnar epithelium lines in the lumen of the stomach, small intestine and large intestine.This type of epithelium has absorptive and secretory functions. The lamina propria is a layer of loose connective tissue containing minor digestive glands, blood vessels and lymphatic tissue. Muscularis mucosa is composed of thin smooth muscle. (2) The submucosa consists of loose connective tissue containing larger blood vessels, lymph vessels and submucous plexus. (3) With the exception of the oral cavity, pharynx, upper esophagus and the anus, where skeletal muscle is to be found, the muscularis externa is made up of smooth muscle which is usually arranged into two layers: an inner circular and an outer longitudinal layer. Between the two layers is a vascular plexus and a nerve plexus. (4) The adventitia can be subdivided into two kinds: fibrosa and serosa. The adventitia of esophagus and the last paragraph of large intestine is composed of fibrosa, while the outer layer covering stomach, small intestine and colon is formed by serosa. 3. Describe the organizational structure of gastric wall Gastric wall can be divided into four layers: mucosa, submucosa, muscularis externa and adventitia. (1) The mucosa is composed of epithelium ,lamina propria and muscularis mucosa. The epithelium is simple columnar epithelium, which is mainly composed of surface mucus cell. No goblet cells are present in the epithelium. Lamina propria contains a large number of - 75 - gastric glands, which are composed of chief cells which can secrete pepsinogen., parietal cells which can produce hydrochloric acid and intrinsic factor, mucous neck cells which can produce mucus and endocrine cells which can produce hormones ,as well as undifferentiated cells which are stem cells. Muscularis mucosa is composed of thin smooth muscles. (2) The submucosa consists of loose connective tissue containing larger blood vessels, lymph vessels and submucous plexus. (3) The muscularis externa is relatively thick, with three layers of smooth muscle. (4) The adventitia is a serous membrane. Ⅳ. Choose the correct answers for each question 1. A 2. B 3. C 4. D 5. E 6. A 7. B 8. C 9. E 10. A Ⅴ. Choose the true or false by “T”&”F” 1. F 2. F 3. F 4. T 5. F 6. F 7. T 8. F 9. T 10. T Gao wei - 76 - DIGESTIVE GLAND Ⅰ. Definitions 1. hepatic lobule 2. portal area 3. pancreas islet 4. bile canaliculus Ⅱ. Fill the blanks 1. The three pairs of large salivary glands are and , . 2. According to the different secretions, the acinus can be divided into two kinds, they are and . 3. According to the diameter of the ducts in large salivary glands, the duct system consists of , and , . 4. The secretory unit of the exocrine pancreas is acinus. , which are the beginnings of intercalated ducts, are usually visible in the lumen of acini. 5. In pancreas islets, secrete glucagon which can raise blood sugar levels; B-cells secrete which can lower blood sugar levels; D-cells produce ; secrete pancreatic polypeptide. 6. is the basic structural unit of the liver, which is a polygonal prism with a at its centre. Anasto- mosing plates of extend radially from the centre. Between the plates and 7. The lining of hepatic sinusoids consists of can be found. and . 8. The perisinusoidal space is an interstitial space between and . Small numbers of - 77 - are present in the perisinusoidal space. They contain and store . 9. Portal areas are found in the angles where adjacent meet. They contain the 'portal triad', which comprises and , . Ⅲ. Questions 1. Describe the structure of pancreas islets 2. Describe the structure of hepatic lobules Ⅳ. Choose the correct answers for each question. 1. Centroacinar cells are ( ) A. the beginnings of intercalated ducts, which are usually visible in the lumen B. the epithelial cells of striated ducts C. acinar epithelial cells D. endothelium E. myoepithelial cells 2. Which of the following descriptions is NOT true about hepatocytes ( ) A. Hepatocytes are large polyhedral cells. B. The cytoplasm is strongly basophilic. C. The smooth endoplasmic reticulum is involved in secreting bile. D. Numerous rough endoplasmic reticulum are found in the cytoplasm. E. Microbodies eliminate the poison of peroxide 3. The characteristics of Kupffer cells are all of the following EXCEPT ( ) A. Kupffer cells are irregular in shape. B. Kupffer cells are found dispersed amongst the endothelial cells. C. They have no abilities to phagocytose. D. Kupffer cells can remove bacteria and foreign bodies. - 78 - E. They can deal with antigens and are involved in immune response. 4. Which of the following statements is NOT true about hepatic sinusoids ( ) A. The epithelial cells appear highly fenestrated. B. No membrane is present on the surface of the fenestrae. C. The basal lamina around sinusoids is incomplete. D. Tight junctions exist between adjacent endothelial cells. E. Sinusoids radiate from the central vein in a lobule. 5. Which is NOT a characteristic of the perisinusoidal space ( ) A. The perisinusoidal space is an interstitial space between the endothelial cells of sinusoids and the hepatocytes. B. Reticular fibers are present in the space. C. Small numbers of fat-storing cells are found in it. D. The fluid inside the space is similar in composition to plasma. E. Villi of hepatocytes reach into the perisinusoidal space. 6. A-cells of pancreas islets can secrete ( ) A. glucagon B. insulin C. pancreatic polypeptide D. somatostatin E. none of the above 7. The wall of the bile canaliculi is composed of ( ) A. simple squamous epithelium B. the plasmalemmas of apposing hepatocytes C. simple cuboidal epithelium D. simple columnar epithelium E. pseudostratified ciliated columnar epithelium 8. Which of the following structures is responsible for a detoxifying function ( ) - 79 - A. rough endoplasmic reticulum B. Golgi complex C. smooth endoplasmic reticulum D. lysosome E. mitochondria 9. The basic structural unit of the liver is ( ) A. hepatocyte B. bile canaliculus C. hepatic plate D. hepatic lobule E. hepatic sinusoid 10. Which of the following may lead to Diabetes ( ) A. lack of glucagon secreted by A-cells B. lack of insulin secreted by A-cells C. lack of somatostatin secreted by B-cells D. lack of pancreatic polypeptide secreted by A-cells E. lack of insulin secreted by B-cells Ⅴ. Choose the true or false by “T”&”F” 1. Each hepatic lobule is a polygonal prism, with a central vein at its centre. ( ) 2. Centroacinar cells are acinar epithelial cells.( ) 3. Pancreas juice is secreted by endocrine portion. ( ) 4. The cytoplasm of hepatocytes is strongly basophilic. ( ) 5. PP-cells secrete somatostatin which inhibits the release of glucagon and insulin. ( ) 6. Only serous acini are present in the sublingual glands. ( ) 7. B-cells secrete glucagon which increases blood sugar levels. ( ) 8. The nuclei of mucous cells are round and pale against the basal portion of the cells. ( ) - 80 - 9. The exocrine pancreas is composed of a large number of mucous acini and ducts. ( ) 10. The fat-storing cells contain fat droplets and store vitamin A. ( ) ANSWERS Ⅰ. Definitions 1. hepatic lobule The hepatic lobule is the basic structural and functional unit of the liver.Each hepatic lobule is a polygonal prism, with a central vein at its centre. Anastomosing plates of hepatic cells (hepatic plates), hepatic sinusoids, perisinusoidal spaces and bile canaliculi extend radially from the central vein. 2. portal area Portal areas are found in the angles where adjacent hepatic lobules meet. They comprise interlobular arteries (branches of the hepatic artery), interlobular veins (branches of the portal vein), and the interlobular bile ducts (branches of hepatic duct ). Small amounts of connective tissue accompanied by small lymphatics and nerves are found in portal areas. 3. pancreas islet The endocrine cells of the pancreas are grouped into small spherical clusters known as islets of Langerhans. The islets are scattered among the exocrine acini, and are extensively vascularised by fenestrated capillaries. Four different cell-types can be distinguished, they are: A-cells,B-cells, D-cells and PP-cells. 4. bile canaliculus The bile canaliculi is the first and smallest biliary passage, extends throughout the entire liver. It is formed by opposing membranes of two - 81 - adjioning hepatocytes. The short, irregular microvilli of adjacent hepatocytes protrude into the canalicular lumen. Hepatocyte lateral borders are reinforced with desmosomes, and tight junctions sequester contents of canalicular lumina and prevent bile leakage. Hepatocytes cells secrete bile into canalicular lumina but no comminication usually exists between bile in the canaliculi and the bloodstream. Ⅱ. Fill the blanks 1. submandibular gland, sublingual gland, parotid gland 2. mucous acinus, serous acinus 3. intercalated ducts, striated ducts, interlobular ducts, lobar and major excretory ducts 4. serous, centroacinar cells 5. A-cells, insulin, somatostatin, PP-cells 6. hepatic lobule, central vein, hepatocytes, hepatic sinusoids, perisinusoidal spaces 7. endothelial cells, Kupffer cells 8. endothelial cells, hepatocytes, fat-storing cells, fat droplets ,vitamin A. 9. hepatic lobules, interlobular arteries, interlobular veins, interlobular bile ducts. Ⅲ. Questions 1. Describe the structure of pancreas islets The endocrine cells of the pancreas are grouped into small spherical clusters known as pancreas islets. The islets are scattered among the exocrine acini, and are extensively vascularised by fenestrated capillaries. Four different cell-types can be distinguished, they are: A-cells, B-cells, D-cells and PP-cells. A-cells are relatively large in size and are usually located at the periphery of an islet. A-cells secrete glucagon, which increases blood sugar levels. B-cells secrete insulin, which lowers blood sugar levels. D-cells produce somatostatin which - 82 - inhibits the release of glucagon and insulin. PP-cells secrete pancreatic polypeptide. 2. Describe the structure of hepatic lobules The hepatic lobule is the basic structural and functional unit of the liver. Each hepatic lobule is a polygonal prism, with a central vein at its centre. Anastomosing plates of hepatic cells (hepatic plates), hepatic sinusoids, perisinusoidal spaces and bile canaliculi extend radially from the central vein. (1) central vein: The central vein is very thin-walled and its endothelial cells are continuous with those of the sinusoids and lie in a meshwork of fine reticular fibres. (2)hepatic plates: Hepatic plates consist of a row of closely-packed hepatocytes. Hepatocytes are polygonal cells. The centrally-located nucleus is spherical, with a prominent nucleolus and scattered chromatin granules. About 25 % of the hepatocyte population are binucleate. The cytoplasm is filled with abundant organelles and inclusions. (3) hepatic sinusoids: Sinusoids form an extensive sponge work between the plates of hepatic cells. They radiate from the central vein in a lobule. They are relatively large and irregular. The lining of sinusoids consists of endothelial cells and Kupffer cells. Plasma has direct access to the hepatocytes, which facilitates metabolic exchange between the liver and the blood. (4) perisinusoidal space: is an interstitial space between the endothelial cells of sinusoids and the liver cells. The microvilli of the hepatocytes extend into the perisinusoidal space, allowing active metabolic exchange between the liver and the plasma. Reticular fibres and small numbers of fat-storing cells are found here. These fat-storing cells contain fat droplets and store vitamin A. - 83 - (5) The bile canaliculi radiate from the central vein. Tight junctions involving the plasmalemmas of apposing hepatocytes form impermeable seals along the length of the canaliculi. In this way, bile is prevented from entering perisinusoidal spaces. Ⅳ. Choose the correct answers for each question. 1. A 2. B 3. C 4. D 5. E 6. A 7. B 8. C 9. D 10. E Ⅴ. Choose the true or false by “T”&”F” 1. T 2. F 3. F 4. F 5.F 6. F 7. F 8. F 9. F 10. T Gao wei - 84 - RESPIRATORY SYSTEM Ⅰ. Definitions 1. blood-air barrier 2. typeⅡpulmonary alveolar cell 3. interalveolar septum (alveolar septum) 4. typeⅠpulmonary alveolar cell Ⅱ. Fill in the blanks 1. The wall of the trachea is composed of three layers and . 2. The bronchial tree system is divided into and 3. Respiratory portion of lungs is composed of and , , . , . Ⅲ. Questions 1. Describe the structure and function of two types of pulmonary alveolar cells. 2. Describe the structure of the trachea. Ⅳ. Choose the correct answers for each question. 1. Which contains numerous alveoli ( ) A. bronchiole B. alveolar duct C. terminal bronchiole D. intrapulmonary bronchus E. interalveolar septum 2. The interalveolar septum does NOT contain( A. alveolar capillary B. elastic fibers C. macrophage D. dust cell E. secretory cell - 85 - ) 3. Which cell is NOT present in epithelium of trachea ( ) A. brush cell B. ciliated columnar cell C. endothelial cell D. basal cell E. goblet cell Ⅴ. Choose the true or false by “T” & “F” 1. Alveolar macrophages belong to the mononuclear phagocyte system. ( )) 2. TypeⅠpulmonary alveolar cells are also termed secretory cells. ( ) 3. The conducting portion of lungs includes the bronchi and respiratory bronchioles.( ) 4. The walls of respiratory bronchioles are populated with alveoli. ( ) ANSWERS Ⅰ. Definitions 1. blood-air barrier Air in the alveoli is separated from capillary blood by a three-layered structure termed the blood-air barrier, which is made up of the continuous endothelium of capillary, the fused basement membranes of the endothelium and typeⅠpulmonary alveolar cells, and typeⅠ pulmonary alveolar cells. 2. typeⅡpulmonary alveolar cell TypeⅡpulmonary alveolar cells are also termed secretory cells, which are round or roughly cuboidal, have large, round nuclei, under an electron microscope have rough endoplasmic reticulum, a welldeveloped Golgi apparatus and rich free ribosomes. - 86 - TypeⅡpulmonary alveolar cells synthesize and srcrete pulmonary surfactant,which contains complexes of phospholipids,protein,and carbohydrate that become part of fluid coating the alveolar surfaces. Surfactant’s detergent-like property prevents collapse of alveoli by reducing surface tension ,thereby facilitating alveolar inflation during inspiration.Type Ⅱcells can become into typeⅠpulmonary alveolar cells. 3. interalveolar septum (alveolar septum) The interalveolar septum contains alveolar capillaries, elastic and reticular fibres, and macrophages. 4. typeⅠpulmonary alveolar cell TypeⅠpulmonary alveolar cells are extremely attenuated cells which line most of the surface area of the alveolus. They are squamous cells, the cytoplasmic portion at the site of nuclei is slightly thickened, which make up an alveolar wall. Under an electron microscope organelles such as Golgi complex, endoplasmic reticulum, and mitochondria are grouped aroud the nucleus,reducing the thickness of the blood-air barrier and leaving large areas of cytoplasm cvirtually free of arganelles. All typeⅠpulmonary alveolar cells have occluding junctions that prevent the leakage of tissue fluid into the aleolar air space. The main role of these cells is to provide a barrier of minimal thickness that is readily permeable to gases. Ⅱ. Fill in the blanks 1. mucosa, submucosa, adventita 2. the conducting portion, the respiratory portion 3. respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli Ⅲ. Questions 1. Describe the structure and function of two types of pulmonary alveolar cells. - 87 - TypeⅠpneumocytes are squamous alveolar epithelial cells, which make up an alveolar wall and blood-air barrier. TypeⅡpneumocytes are also termed secretory cells, which are round or roughly cuboidal cells with large round nuclei, under an electron microscope have rough endoplasmic reticulum, a well - developed Golgi apparatus and osmophilic multilamellar bodies. These bodies contain rich surfactant. The surfactant present may reduce the surface tension, plays a role in stabilizing alveolar expansion. 2. Describe the structure of the trachea. The wall of the trachea is composed of three layers: mucosa, submucosa and adventitia. The mucosa is covered with pseudostratified ciliated columnar epithelium, which may be divided into five types: ciliated columnar cells, brush cells, goblet cells, basal cells, small granular cells. The submucosa is composed of loose connective tissue and blood vessels, lymphatics and numerous mixed glands. The adventitia is constructed of the cartilage rings surrounded by dense connective tissue. Ⅳ. Choose the correct answers for each question. 1. B 2. E 3. C Ⅴ. Choose the true or false by “T” & “F” 1. T 2. F 3. F 4. T Hong wei URINARY SYSTEM - 88 - Ⅰ. Definitions 1. nephron 2. filtration membrane 3. juxtaglomerular cell 4. macula densa 5. renal corpuscle Ⅱ. Fill in the blanks 1. Nephron consists of and . 2. Renal tubule can be divided into three segments and , . 3. Renal corpuscle is composed of and 4. Henle’s Loop is made up of , . and 5. Renal corpuscle has two poles . and . 6. Parietal layer of Bowman' s capsule is epithelium. 7. Visceral layer of Bowman' s capsule is , the secondary processes of it interdigitate, defining elongated spaces is called . 8. Filtration membrane is also called of , It is composed , and 9. The longest segment of renal tubule is and . , its functions are . 10. Under light microscope the cell free surface of proximal convoluted tubule presents , its function is 11. Thin segment is lined by epithelium. 12. The juxtaglomerular complex is composed of and . , . 13. Juxtaglomerular cells are derived from the smooth muscle cells in the wall of the . - 89 - 14. Under electron microscope the structures of increasing surface areas of cell of proximal convoluted tubules have and , . 15. The glomerular capillary is under electron microscope Ⅲ. Questions 1. What is the component of the filtration membrane? If it is damaged seriously, what can be occurred in the urine? . 2. What is the structure and function of renal glomerulus? 3. What is the component and function of the juxtaglomerular complex? 4. What is the component of nephron? 5. Compare the structures of proximal convoluted tubule with distal convoluted tubule under light microscope. Ⅳ. Choose the correct answers for each question 1. Which is right about the component of nephron( ) A. renal corpuscle, urinary tubule and thin segment B. renal corpuscle, distal convoluted tubules and thin segment C. renal corpuscle, proximal tubules, distal tubules and thin segment D. renal corpuscle, proximal tubules, distal convoluted tubules and thin segment E. renal corpuscle, distal tubules and thin segment 2. Which is wrong about the features of renal corpuscle( ) A. It is composed of glomerulus and Bowman' s capsule B. It has vascular pole and urinary pole C. the vascular pole which the afferent arteriole enter the glomerulus D. Its urinary pole connects with distal convoluted tubule E. The glomerulus is surrounded by Bowman' s capsule 3. Which is NOT structures of nephron( A. renal corpuscle - 90 - ) B. collecting tubule C. thin segment D. proximal tubule E. distal tubule 4. Which is WRONG about the features of proximal tubule( ) A. The cytoplasm of epithelial cell is weakly basophilic B. The epithelial cell is large, pyramidal or cuboidal C. The boundary of cell is not clear D. Nucleus is round and basally-located E. Brush borders on the free surface of cells are present 5. Which is wrong about the features of distal tubule( ) A. Epithelial cell is cuboidal in shape B. Nucleus is round and centrally-coated C. Cell boundary is clear D. The microvilli of the free surface of cells are short and loose E. The basal infoldings are not obvious Ⅴ. Choose the true or false by “ T” ﹠“ F” 1. Nephron consists of Bowman's capsule and renal tubules.( 2. The glomerular capillary is continuous capillary. ( ) ) 3. Slit pores between adjacent secondary processes of podocytes are covered by slit membranes.( ) 4. Macula densa locates at the urinary pole of renal corpuscle.( ) 5. Juxtaglomerular cells are derived from the smooth muscle cells in the wall of the efferent arteriole.( ) 6. A renal glomerulus is a cluster of capillaries between afferent and efferent arterioles. ( ) 7. The juxtaglomerular complex consists of three structures: juxtaglomerular cells, macula densa and intraglomerular mesangial cells.( - 91 - ) 8. Macula densa is a special region of the proximal tubule. Its cells become tall, narrow and are closely packed together.( ) ANSWERS Ⅰ. Definitions 1. nephron Nephron is basic structural and functional unite of kidney, it is composed of renal corpuscle and renal tubule. 2. filtration membrane Filtration membrane consists of fenestrated endothelium of capillary, basement membrane and slit membrane of podocytes. 3. juxtaglomerular cells Juxtaglomerular cells are derived from the smooth muscle cells in the wall of the afferent arteriole. They are cuboidal in shape and cytoplasm contains granules. They can secrete rennin. 4. macula densa Macula densa is a special region of the distal tubule, situated near to the afferent arteriole. Its cells become tall, narrow and closely packed together. It is ionic receptor. 5. renal corpuscle Renal corpuscle is spherical and that part of nephron responsible for the filtration of plasma. It includes glomerulus and Bowman's capsule. Ⅱ. Fill in the blanks 1. renal corpuscle, renal tubule 2. proximal tubules, distal tubules, thin segment 3. glomerulus, renal capsule 4. proximal straight tubule, distal straight tubule, thin segment - 92 - 5. vascular pole, urinary pole 6. simple squamous epithelium 7. podocyte, slit pore 8. filtration barrier, endothelium of fenestrated capillary, basement membrane, slit membrane of podocyte 9. proximal convoluted tubule, re-absorption secretion 10. brush border, increasing free surface areas of cell of proximal convoluted tubules and adding re-absorption 11. simple squamous epithelium 12. juxtaglomerular cell, macula densa, extraglomerular mesangial cell 13. afferent arteriole 14. microvilli , lateral processes, basement plasma infolding 15. fenestrated capillary Ⅲ. Questions 1. What is component of the filtration membrane? If it is damaged seriously ,what can be occurred in the urine? (1) fenestrated endothelium of capillary, basement membrane and slit membrane of podocyte. (2) Proteins and blood cells (erythrocyte ) 2. What is the structure and function of renal glomerulus? It is cluster of capillaries between afferent and efferent arterioles, It is fenestrated capillary under electron microscope It is responsible for the filtration of plasma 3. What is the component and function of the juxtaglomerular complex? Juxtaglomerular cell produce renin macula densa ionic receptor. extraglomerular mesangial cell transport information 4. What is the component of nephron? - 93 - Renal corpuscle glomerulus renal capsule proximal tubule proximal convoluted tubule straight part of proximal tubule Renal tubule thin segment Henle’s Loop straight part of distal tubule distal tubule distal convoluted tubule 5. Compare the structures of proximal convoluted tubule (PCT) with distal convoluted tubule (DCT) under light microscope. PCT Shape DCT Lumen is small and Lumen is large and irregular,wall is thick regular,wall is thin large pyramidal or Epithelial cell small, cuboidal cuboidal Nucleus round, basally-located round, centrally-located Cell's boundary no clear clear Cytoplasm strongly acidophilic weakly acidophilic Brush borders present no present Basal striation present present, more obvious Ⅳ. Choose the correct answers for each question 1. C 2. D 3. B 4. A 5. E ⅤChoose the true or false by “ T” ﹠“ F” 1. F 2. F 3. T 4. F 5. F 6. T 7. F 8. F. Ren yi-min - 94 - ENDOCRINE SYSTEM Ⅰ. Definitions 1. paracrine secretion 2. parafollicular cell 3. Herring body 4. hypophyseal portal system 5. diffuse neuroendocrine system(DNES) 6. adrenal chromaffin cell 7. steroid-secreting cell Ⅱ. Fill in the blanks 1. According to the variability in chemical nature of hormones, endocrine cells are classified in two types: and . 2. The thyroid follicles are mainly lined by epithelium. Its function is to synthesize the hormones. 3. The parafollicular cells or C-cells are found as part of the or as isolated clusters between . 4. The chief cells in parathyroid glands secret , which serum Ca2+ levels. 5.The adrenal cortex can be subdivided into three layers from external to internal side in order : , ;secreting and and , , respectively. 6. H-E stain allows the recognition of three cell types in the pars distalis of adenohypophysis: , and . 7. The neurosecretions of hypothalamus are transported along the axons and accumulate at their ending in the pars nervosa. Here they form - 95 - structures known as , which are visible in the light microscopy, containing and 8. Hypophyseal portal system consists of and . , . 9. The diffues neuroendocrine system (DNES) consists of APUD (amine precursor uptake and decarboxylation and . 10. The chromaffin cells are found in the of adrenal gland. The chromaffin cells can produce and . 11.Steroid-secreting cells have the characteristic ultrastructures: , , , ect. 12. Thyroid colloid is composed of a glycoprotein called . 13. The secretions of endocrine cells are called circulate in the blood and act on the . They tissues or organs. 14. The children who are hypothyroid from birth may present characterized by arrested and , development. 15. The hypophysis (pituitary gland) consists of and . The former is subdivided into three portion: and .The latter is , and . 16. Excessive production of the growth hormones may result in in children, conversely, result in . 17. The glucocorticoids are mainly secreted by the affect the metabolism of , , they , and 18. The luteinizing hormones (LH) promote . and in the female; while stimulate testosterone production by cells in males, so they are also called 19. Prolactins are secreted by . cells in the pars distalis of hypophysis. Oxytocins are synthesized by the 20. The activities of cells of the pars distalis are controlled by hormones and hormones of hypothalamus . - 96 - . Ⅲ. Questions 1. The structural characteristics of endocrine glands 2. The main hormones of regulating blood calcium and their origin 3. How does hypothalamus communicate with the hypophysis 4. The structure and function of thyroid gland. 5. The main structure and function of adrenal cortex 6. The structural features and functions of pars distalis Ⅳ.Choose the correct answers for each question. 1.The containing nitrogen-secreting cells ( ) A. have no secretory granules B. are rich in smooth endoplasmic reticulum C. have well-developed rough endoplasmic reticulum D. have mitochondria with tubule and vesicular cristae E. have many lipid droplets 2. Usually, the thyroid epithelium is ( A. cuboidal B. high columnar C. squamous D. goblet-like E. variety of size 3. Cretinism results from ( ) A. more thyroid hormones B. less thyroid hormones C. more growth hormones D. less growth hormones E. less calcitonin 4. Calcitonin-secreting cells are ( ) A. the chief cells in parathyroid glands B. the parafollicular cells in thyroid - 97 - ) C. the follicular epithelium in thyroid D. the cells of zona fasciculata in adrenal glands E. the cells of zona reticularis in adrenal glands 5. In adrenal glands ( ) A. the zona glomerulosa secretes glucocorticoids B. the zona fasciculata secretes mineralocorticoids C. the zona reticularis secretes androgen D. the chromaffin cell secretes oxytocin E. the chromaffin cell secretes vasopressin 6. The pars distalis does not contain ( ) A. acidophils B. chromophobes C. basophils D. pituicytes E. endothelium 7. Herring bodies contain hormones synthesized by ( ) A. pituicytes B. secretory neurons (supraoptic and paraventricular nuclei) of hypothalamus C. acidophils D. basophils E. chromophobes 8. The basophils of adenohypophysis do not secrete ( ) A. thyrotropin B. corticotropin C. follicle-stimulating hormone D. interstitial cell stimulating hormone E. prolactin 9. The excessive secreting the growth hormone results in ( - 98 - ) A. Cretinism B. Pituitary gigantism C. Pituitary midget D. Diabetes insipidus E. Cushing syndrome 10. The neurohypophysis releases ( ) A. prolactin and growth hormone B. gonadotropic hormone and thyrotropin C. corticotrophin and prolactin D. vasopressin and oxytocin E. prolactin and oxytocin Ⅴ. Choose the true or false by “T” & “F” 1. The endocrine system does not act alone in the control of body functions. It interacts closely with the nervous system and the immune system. ( ) 2. The hypophyseal portal system is of utmost importance because it contains hypothalamic hormones that control the function of the cells of neurohypophysis.( ) 3. Besides the endocrine glands, there are many isolated endocrine cells in the body.( ) 4. The endocrine glands include the adrenal glands, the thyroid, and the hypophysis, as well as the sweat glands.( ) 5. Many endocrine cells produce hormones that act at a short distance by diffusing through the extracellular matrix.This is called paracrine secretion. ( ) 6. The endocrine cells are always very close to continuous capillaries duo to no ducts.( ) 7. The neurohypophysis synthesizes the hormones and releases the hormones into the blood.( ) - 99 - 8. Calcitonin from the parathyroid gland lowers blood Ca2+ concentration.( ) 9. As a result of the dissolution of the lipids during tissue preparation, the fasciculata cells in adrenal gland appear vacuolated in common histological preparations.( ) 10. The pars nervosa of neurohypophysis consists of secretory cells, axons from hypothalamic neurons, pituicytes and fenestrated capillaries. ( ) ANSWERS Ⅰ. Definitions 1. paracrine secretion Many endocrine cells produce hormones that act at a short distance by diffusing through the extracellular matrix. This is called paracrine secretion. 2. parafollicular (C- cell ) The parafollicular, or C- cell, is found as the part of the follicular epithelium or as the isolated clusters between thyroid follicles. Parafollicular cells are larger and less stained than thyroid follicular cells with the light microscope. These cells are responsible for the synthesis and secretion of calcitonin, a hormone whose main effect is to lower blood calcium levels by inhibiting bone resorption. Secretion of calcitonin is triggered by an elevation in blood calcium concentration. 3. Herring body The secretory neurons in the supraoptic and paraventricular nuclei make the production of the neurosecretory material. The neurosecretions are transported along the axons and accumulate at their endings in the pars nervosa. Here they form structures known as Herring bodies, which are visible in the light microscope and conain the two hormones: - 100 - argininevasopressin—also called antidiuretic hormone (ADH)—and oxytocin. 4. hypophyseal portal system The superior hypophyseal arteries divide into a primary capillary plexus in the median eminence and the neural stalk. These capillaries then rejoin to form hypophyseal portal veins that develop into a secondary capillary plexus in the adenohypophysis . This hypophyseal portal system is of utmost importance because it carries neurohormones from the median eminence to the adenohypophysis where they control the function of the cells of this part of the hypophysis. 5. diffues neuroendocrine system (DNES) The diffues neuroendocrine system (DNES) consists of APUD (amine precursor uptake and decarboxylation) and secretory neurons. DNES cells are largely derived from the neural crest cells of the embryonic nervous system and can be identified and localized by immunocytochemical methods or other cytochemical techniques for specific amines. These cells are widespread throughout the organism: in the respiratory, the urinary, the gastrointestinal systems, the thyroid and the hypophysis. 6. adrenal chromaffin cell The adrenal chromaffin cells are also called medullary cells. The secretory granules of medullary cells appear brown color with chromatecontaining fixative. These granules contain epinephrine or norepinephrine. 7. steroid-secreting cell Cells that secrete steroids are found in various organs of the body (eg, testes, ovaries, adrenals). They are polyhedral or rounded acidophilic cells with a central nucleus and a cytoplasm that is usually—but not invariably—rich in lipid droplets. The ultrastructure of steroid-secreting cells contain the abundance of the smooth endoplasmic reticulum, - 101 - spherical or elongated mitochondria with tubular cristae, lipid droplets, and Golgi complex. Ⅱ. Fill in the blanks 1. steroid-secreting cells, nitrogen-based-secteting cells 2. A simple cuboidal epithelium, thyroxine and triiodthyronine (thyroid hormones) 3. follicular epithelium, thyroid follicles 4. parathyroid hormone, high (increase) 5. zona glomerulosa, zona fasciculata, zona reticularis, mineralocorticoids, glucocorticoidsand, androgens 6. chromophobes, basophils, acidophols 7. Herring bodies, oxytocin, vasopressin (antidiuretic hormone) 8. primary capillary plexus, hypophyseal portal vein, secondary capillary plexus 9. secretory neurons 10 adrenal medulla, epinephrine, norepinephrine 11. Rich smooth endoplasmic reticulum, mitochondria with tubular cristae, rich lipid, droplets 12. iodinated thyroglobulin 13. hormones, target 14. Cretinism, physical, mental 15. adenohypophysis, neurohypophysis, pars distalis, pars tuberalis, pars intermedia, pars nervosa, infundibulum 16. pituitary gigantism, pituitary midget 17. zona fasciculata, proteins, lipids, carbohydrates 18. ovulation, corpus luteum formation, Leydig, interstitial cell stimulating hormones 19. mammotropic, supraoptic and paraventricular nuclei in hypothalamus - 102 - 20. hypothalamic releasing hormones, hypothalamic release inhibiting hormones Ⅲ. Questions 1. The structure characteristics of endocrine glands Endocrine glands are ductless. The endocrine cells may form anastomosing cords interspersed between dilated blood capillaries (e.g. adrenal gland, parathyroid, anterior lobe of the pituitary); or they may arrange themselves as vesicles or follicles filled with noncellular material (e.g. the thyroid gland). The secretions of endocrine cell are called the hormones, which are picked up and transported to target site of action by the bloodstreams. 2. The main hormones of regulating blood calcium and their origin The parafollicular, or C-cell in the thyroid glands are responsible for the synthesis and secretion of calcitonin, a hormone whose main effect is to lower blood calcium levels by inhibiting bone resorption. . The chief cells of parathyroid glands secrete the parathyroid hormone, which increases the number and activity of osteoclasts and thus promotes the absorption of the calcified bone matrix and the release of Ca2+ into the blood. The results increase the concentration of Ca2+ in the blood. 3. How does hypothalamus communicate with the hypophysis (1)directly The neurohypophysis consists of the pars nervosa and the neural stalk. The pars nervosa is composed of unmyelinated axons of secretory neurons situated in the supraoptic and paraventricular nuclei. The hormones of supraoptic and paraventricular nuclei are transported along the axons of these neurons and accumulate in the ends of these axons, which are situated in the neurohypophysis. These hormones are released by exocytosis, enter capillaries of the neurohypophysis, and are distributed by the blood. - 103 - (2)indirectly The hypophyseal portal system The main mechanism takes place through peptide hormones produced in the hypothalamic aggregates of neurosecretory cells and stored in the median eminence . When liberated, they are transported to the pars distalis through the hypophyseal portal system and act on specific cells of the pars distalis. Most of these hormones are hypothalamic-releasing hormones and hypothalamic-inhibiting hormones.They may affect the function of the hypophysis and consequently the function of many organs and tissues. 4. The structure and function of thyroid gland Thyroid tissue is composed of 20–30 million thyroid follicles. An extensive blood and lymphatic capillary network surround the follicles. The follicles are lined by a simple squamous epithelium and their central cavity contains the colloid containing thyroglobulin. The thyroid epithelium rests on a basal lamina. These cells are rich in rough endoplasmic reticulum, well-developed Golgi complex, abundant lysosomes, and small secretory granules. The thyroid epithelium function is to synthesize the hormones thyroxine (T4) and triiodothyronine (T3), which are important for growth, for cell differentiation, and for the control of oxygen consumption and the basal metabolic rate in the body. Thyroid hormones affect the metabolism of proteins, lipids, and carbohydrates. Another type of cell present in the thyroid, the parafollicular, or C-cell, is found as part of the follicular epithelium or as isolated clusters between thyroid follicles. Parafollicular cells are larger than thyroid follicular cells and with the light microscope appear less stained. They have a small amount of rough endoplasmic reticulum, long mitochondria, a large Golgi complex and numerous small granules. These cells are responsible for the synthesis and secretion of calcitonin, a hormone - 104 - whose main effect is to lower blood calcium levels by inhibiting bone resorption. 5. The structure features and functions of adrenal cortex The cells of the adrenal cortex, which have the typical ultrastructure of steroid-secreting cells, synthesize and secrete steroid hormone. The adrenal cortex can be subdivided into three concentric layers: the zona glomerulosa, the zona fasciculata, and the zona reticularis. These layers occupy 15%, 65%, and 7%, respectively, of the total volume of the adrenal glands. (1)The layer immediately beneath the connective tissue capsule is the zona glomerulosa, in which columnar or pyramidal cells are arranged in closely packed, rounded, or arched cords surrounded by capillaries. The main product of the zona glomerulosa is a mineralocorticoid called aldosterone. (2)The next layer of cells is known as the zona fasciculata because of the arrangement of the cells in one- or two-cell thick straight cords that run at right angles to the surface of the organ and have capillaries between them. The cells of the zona fasciculata are polyhedral, with a great number of lipid droplets in their cytoplasm. The zona fasciculata and possibly the zona reticularis secrete glucocorticoids, especially cortisol. (3)The zona reticularis, the innermost layer of the cortex, lies between the zona fasciculata and the medulla; it contains cells disposed in irregular cords that form an anastomosing network. These cells are smaller than those of the other two layers. Lipofuscin pigment granules in the cells are large and quite numerous.They produce the dehydroepiandrosterone, a weak androgen. 6. The structure features and functions of pars distalis - 105 - The main components of the pars distalis are cords of cells interspersed with capillaries. The pars distalis accounts for 75% of the hypophysis. The electron microscopy show the cells of pars distalis have numerous secretory granules, long mitochondria, cisternae of rough endoplasmic reticulum, and Golgi complex. Common stains allow the recognition of three cell types in the pars distalis: chromophobes and two types of chromophils called basophils and acidophils. The subtypes of basophil and acidophil cells are named for the hormones they produce. Chromophobes do not stain intensely and probably are undifferentiated cells. Acidophils, accounting for 40% of pars distalis of hypophysis, are large and polyhedral in shape. The cytoplasm of them contains acidophlic secretory granules. They secret hormones—growth hormone (GH, somatotropin) and prolactin (PRL). Basophils, accounting for 10% of pars distalis of hypophysis, vary in size and in shape. The cytoplasm of them contains basophlic secretory granules. They secret hormones —follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyrotropin (TSH), adrenocorticotropin (ACTH). Ⅳ. Choose the correct answers for each question. 1. C 2. A 3. B 4. B 5. C 6. D 7. B 8. E 9. B 7. F 8. F 9. T 10. D Ⅴ. Choose the true or false by “T” & “F” 1. T 2. F 3. T 4. F 5. T 6. F 10. F Liang yu - 106 - EYES AND EARS Ⅰ. Definitions 1. rod cell of photoreceptor 2. cone cell of photoreceptor Ⅱ. Fill in the blanks 1. The wall of the eye ball is divided into , and three layers. 2. Cornea is transparent. From anterior to posterior, it’s composed of five layers and , , , . 3. The iris is composed of loose connective tissue containing and and .The iris is divided into , three parts. 4. The choroid is composed mainly of loose connective tissue which is heavily and . 5. The retina contains four layers of cells, proceeding inwards from the exterior they are , , and . 6. Photoreceptor cells are photosensitive bipolar neurons. There are two types: and . 7. Cones contain three photopigments, the three photopigments are sensitive to , or light. 8. The spiral organ of Corti is the site at which mechanical vibrations are translated into . It consists of arranged in a complex manner. Ⅲ. Questions 1. Why is cornea transparent? 2. What is the ten layers structure of the retina? - 107 - and Ⅳ. Choose the correct answers for each question. 1. Refracting medias of the eyeball are the ( ) A. fovea centralis B. tarsus C. optic disc D. cornea E. sclera 2. Which of he following cells sensitive to night vision ( ) A. the Kupffer cells B. the goblet cells C. the spiral organ of Corti D. the cones E. the rods 3. Each of following statements concerning corneal layers is true EXCEPT? ( ) A. the epithelium is stratified squamous B. the endothelium has a basement membrane C. the stroma is acellular D. the stroma contains collagen E. Bowman’s menbrance is anterior to Descemet’s membrance 4. Which of the following statements best describes the functional histology of the sclera? ( ) A. It is covered by an epithelium. B. It contains more blood vessels than the choroid layer. C. It is richly pigmented. D. It has few fibroblasts and collagen fibers. E. Its anterior component is modified to form the cornea. 5. Which of the following membrane conducts traveling wave of deform at? ( ) - 108 - A. reticular membrane B. tectorial membrane C. basilar membrane D. vestibular membrane E. tympanic membrane 6. Which of the following membrane secreted from spiral limbus and makes contact with tips of hair cells? ( ) A. reticular membrane B. tectorial membrane C. basilar membrane D. vestibular membrane E. tympanic membrane 7. Which of the following membrane covered by stratified squamous epithelium on lateral surface? ( ) A. reticular membrane B. tectorial membrane C. basilar membrane D. vestibular membrane E. tympanic membrane 8. The description of tunica vascularis,which one is WRONG ( ) A. Mainly comprise by loose connective tissue B. rich in blood vessels C. rich in chromatophore cell D. rich in photoreceptor cell E. light intensity will cause some structural changes 9. Which is NOT a characteristic of a ganglion cell of retina ( A. These are multipolar neurons. B. located in the innermost layer of the retina C. dendrite with bipolar cells to form the synapse - 109 - ) D. axons be part of the optic nerve E. before other cells in the retina to stimulate the feelings of light 10. Which one of the following receive color and high lights ( ) A. pigment epithelial cell B. cone cell C. rod cell D. bipolar cell E. ganglion cell Ⅴ. Choose the true or false by “T” & “F” 1. Both the anterior chamber and the posterior chamber contain a protein rich fluid called aqueous humor. ( ) 2. Descemet’s membrance can be seen with the light microscope to be a thin homogeneous structure. ( ) 3. The endothelium of the cornea is typical simple squamous epithelium.( ) 4. The lens has 3 principal components: lens capsule; subcapsular epithelium and lens fibers. ( ) 5. The anterior part of the retina is photosensitive and constitutes the inner lining of the ciliary body and the posterior part of the iris.( ) 6. The optical part of the retina is a more complex structure and consists of the following layers: an outer layer of photosensitive cells, the rods and cones; a layer of bipolar neurons ; a layer of ganglion cells. ( ) 7. The corneoscleral junction or limbus is an area of transition from the transparent collagenous bundles of the cornea to the white opaque fibers of the sclera. ( ) 8. The functions of the vestibulocochlear apparatus are related to equilibrium and hearing. ( ) 9. The external ear has an regular form and consists mainly of a plate of elastic cartilage covered by a layer of skin on both sides. ( - 110 - ) 10. The supporting cells disposed between the receptors are columnar and prismatic , with their nuclei at the top of the cell and microvilli in its surface membrane. ( ) ANSWERS Ⅰ. Definitions 1. rod cell of photoreceptor Rods are highly-modified neurons. Each rod has a rounded ceil body with a small, spherical, darkly-stained nucleus. Two processes arise from opposite ends of the cell body. The one directed towards the pigment epithelium has a cylindrical outer segment and an inner segment.Rod cells showed long and thin rod-shaped lateral protrusions, said rod, depending on the rod outer segment of the film, there are many parallel disks by repeatedly folded plasma membrane formed gradually after the formation of isolated and at the end with the cell membrane shedding. Membrane disc inlaid with the rhodopsin. 2. cone cell of photoreceptor The outer protrusions of cone cells are like a cylindrical cone, known as cones. Cone outer segment disc membranes are not separated with the membrane and does not fall off. The membrane disc inlaid with the visual pigment. Ⅱ. Fill in the blanks 1. fibrosa, tunica vascularis, retina 2. corneal epithelium, Bowman's membrane, substantia propria, descemet’s membrane, corneal endothelium 3. blood vessels, pigments, anterior border layer, iris stroma, iris epithelium 4. vascularised, pigmented. 5. pigment epithelium, photoreceptor cells, bipolar cells, ganglion cells 6. rods, cones - 111 - 7. red, green, blue 8. nervous impulses, supporting cells, hair cells Ⅲ. Questions 1. Why is cornea transparent? Since it has to be transparent to allow light to enter the eye, there are no blood vessels in the cornea. It is composed of very tightly packed collagen fibers just like the sclera (i.e., the white of the eye). But whereas the collagen fibers in the sclera are randomly packed together (thus making it opaque), the fibers in the cornea are packed together in an organized pattern which is what makes it transparent. 2. What is the ten layers structure of the retina. The retina is the innermost layer of the eyeball. Under the light microscope, the retina is seen to have ten layers which are in fact made up of the cell bodies and processes of the four cell-types already mentioned. From the surface in contact with the choroid inwards, the layers are as follows: (i) The pigment epithelium. (ii) A layer of rods and cones consisting of the outer and inner segments of the rods and cones. (iii) An external limiting membrane formed from the outer ends of Müller's cells. (iv) in outer nuclear layer containing the nuclei of the rods and cones. (v) An outer plexiform layer consisting of a dense network of axons of rods and cones, dendrites of bipolar cells, and processes of horizontal cells. (vi) An inner nuclear layer containing the nuclei of bipolar cells, horizontal cells, amacrine cells and Müller's cells. (vii) An inner plexiform layer consisting of axons of bipolar cells, amacrine cell processes, and ganglion cell dendrites. - 112 - (viii) A ganglion cell layer consisting of cell bodies of ganglion cells. (ix) A nerve fibre layer consisting mainly of axons of ganglion cells. (x) An internal limiting membrane comprising the terminations of the processes of Müller's cells and their basement membrane. Ⅳ. Choose the correct answers for each question. 1. D 2. E 3. C 4. E 5. C 6. B 7. E 8. D 9. E 10. B Ⅴ. Choose the true or false by “T” & “F” 1. T 2. F 3. T 4. T 5. F 6. T 7. T 8. T 9. F 10. F Yao qing-bin - 113 - SKIN Ⅰ. Definitions 1. keratohyalin granule 2. melanin granule 3. hair bulbs 4. hair papilla Ⅱ. Fill in the blanks 1. Skin is mainly composed of tissue and 2. Skin consists of two layers and 3. The appendage of skin includes and tissue. . , , . 4. Epidermis is epithelium. 5. Epidermis is composed of two types of cells 6. The thick epidermis includes five layers , . , , and 7. Dermis can be divided into two layers and 8. The stratum basale of epidermis rests on the composed of and . , it is mainly cells. 9. Above the stratum spinosum, it is , the cells of this layer are filled with granules. 10. Superficial to the stratum lucidum, it is , the cells of this layer are filled with . 11. The hair is divided into two parts and 12. The hair root is surrounded by ; its lower end is enlarged and termed . 13. The growing point of hair is . 14. The arrector pili are a bundle of connecting the papilla of the dermis and the hair follicle. Ⅲ. Questions - 114 - 1. Describe the structure of dermis? 2. Describe the structure of hair? 3. Describe the structure the epidermis? Ⅳ. Choose the correct answers for each question 1. Which are components of skin? ( ) A. epidermis and mesothelium B. epidermis and endothelium C. epidermis and epithelium D. epidermis and dermis E. mesothelium and dermis 2.Which is developing layer of epidermis A. stratum corneum B. stratum granulosum C. stratum lucidum D. stratum spinosum E. stratum basale 3.Which layer keratohyalin granules are mainly found in( A.stratum granulosum B.stratum corneum C.stratum spinosum D.stratum lucidum E.stratum basale 4.Which is WRONG about reticular layer of dermis( A. is irregular dense connective tissue B. contains a lot of paralleling collagenous fibers C. contains a lot of interlacing elastic fibers D. contains blood vessels E. contains sweat glands 5.Which is WRONG about hair( ) - 115 - ) ) A. Hair root is implanted in the skin B. Hair is composed of horny cells C. Hair root is surrounded by hair follicle D. Hair papilla is growing point of hair E. Hair includes hair shaft and hair root ⅤChoose the true or false by “ T” ﹠“ F” 1. Skin is composed of epidermis and endothelium.( ) 2. The epidermis consists of a non-keratinized stratified squamous epithelium.( ) 3. The skin appendages include hairs, nails, sebaceous glands and sweat glands.( ) 4. Beneath the epidermis lies the hypodermis.( ) 5. In all epidermis five layers can be distinguished.( ) 6. The cell of the epidermis can be classified two types: keratinized cells and non-keratinized cells.( ) 7. Non-keratinized cells include melanocytes, Langerhans cells and Merkel’s cells.( ) 8. The dermis can be subdivided into two layers: the papillary layer and hypodermis layer.( ) 9. The reticular layer is thicker and composed of irregular dense connective tissue.( ) 10. The dermis contains bundles of paralleling collagenous fibers and elastic fibers.( ) ANSWERS Ⅰ. Definitions 1. keratohyalin granule They distribute in cytoplasm of granular layer of epidermis, which are heavily stained hematoxylin (strongly basophilic granules), under electron microscope, they are not enveloped by membrane. - 116 - 2. Melanin granule The cytoplasm of melanocyte contains melanosomes. When melanosomes are filled with melanin, they are termed melanin granules. 3. hair bulb The lower end of hair root and hair follicle are enlarged and termed the hair bulb. 4. hair papilla The bottom of the hair bulb is invaginated and filled with the hair papilla, which is composed of connective tissue rich in nerve fibers and blood vessels. Hair papilla provides the nutrition for the hair bulb. Ⅱ. Fill in the blanks 1. epithelial tissue, connective tissue 2. epidermis, dermis 3. hairs, nails, sebaceous glands, sweat glands 4. keratinized stratified squamous epithelium 5. keratinized cells , non-keratinized cells 6. stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum 7. papillary layer, reticular layer 8. basement membrane, columnar or cuboidal 9. stratum granulosum, keratohyalin granules 10. stratum corneum, keratin 11. hair shaft, hair root 12. hair follicle, hair bulb 13. hair bulb 14. smooth muscle Ⅲ. Questions 1. What is the structure of dermis? - 117 - The dermis is composed of connective tissue. It can be subdivided into two layers: the papillary layer and the reticular layer. The papillary layer is the part of the dermis that fuses with the epithelium, and is formed by numerous papillae. It contains finer collagenous fibers, rich capillaries and nerve endings. The reticular layer is thicker and composed of irregular dense connective tissue. It contains bundles of interlacing collagenous fibers and elastic fibers, blood vessels, hair follicle, sebaceous glands and sweat glands are also present in large numbers. 2. What is the structure of hair? Hair is divided into two parts: hair shaft and hair root. The free part of a hair outside the skin is termed the hair shaft. The hair root is implanted in skin and is surrounded by a hair follicle. A hair is composed of regularly-arranged horny cells. Hair follicle consists of epithelial and connective tissues. The lower end of hair root and hair follicle are enlarged and termed the hair bulb. The bottom of the hair bulb is invaginated and filled with the hair papilla, which is composed of connective tissue rich in nerve fibers and blood vessels. Hair papillae nourish the hair bulbs. 3. What is the structure of five layers of the thick epidermis? 1) Stratum basale LM: This is a layer of low columnar or cuboidal cells resting on a basement membrane. EM : In cytoplasm there are free ribosomes and keratin filaments Between adjacent cells desmosomes are present. 2) Stratum spinosum LM: Stratum spinosum is composed of 4 ~10 layers of larger polyhedral cells. Many spinous processes are to be found on the cell surface. EM: In cytoplasm there are lamellated granules (membrane-coated) - 118 - containing glycolipid and steroid and bundles of keratin filaments. 3) Stratum granulosum LM: Stratum granulosum is composed of 3~5 layer of flattened spindle-shaped cells. Their nuclei and organelles are degenerate. In cytoplasm there are keratohyalin granules which are intensely basophilic. EM: Bundles of keratin filaments increase. A number of lamellated granules are present and migrate to the periphery of the cell or even to the intercellular space. keratohyalin granules are no membrane-coated. 4) Stratum lucidum LM: Stratum lucidum is made up of 3-4 layers of flattened cells. The nuclei and organelles of cells no longer exist. They appear as red homogeneous and transparent 5) Stratum corneum LM: Stratum corneum consists of many layers of flattened horny cells. The nuclei and organelles lost. EM: The cytoplasm of horny cells filled with keratin. The lipid sheet between cells and thickened cell membrane are present. Ⅳ. Choose the correct answers for each question 1. D 2. E 3. A 4. B 5. D ⅤChoose the true or false by “ T”﹠“ F” 1. F 2. F 3. T 4. F 5. F 6. T 7. T 8. F 9. T 10. F Ren yi-min - 119 - MALE REPRODUCTIVE SYSTEM Ⅰ. Definitions 1. spermatogenic cell 2. blood- testis barrier 3. Leydig cells Ⅱ. Fill in the blanks 1. The seminiferous tubules are lined with a specialized stratified epithelium known as . 2. The seminiferous epithelium rests upon a types of cells and and consists of two . 3. From the periphery to the lumen of seminiferous epithelium, successive generations of spermatogenic cells are distinguishable. These includes , , , , 4. Among spermatogenic cells, . are situated adjacent to the basal membrane. 5. migrate from the basal compartment to the middle zone of the seminiferous tubule and become the largest spermatogenic cells within the seminiferous epithelium. 6. By the first meiosis, one primary spermatocyte divided into two meiosis, one secondary spermatocyte divided into 7. By the two which are haploid. 8. Each spermatid is transformed by a complex process of differentiation, termed , into a . 9. Tight junctions are present between two adjacent near their bases, which isolate spermatogonia from more luminal germ cells. 10. The Sertoli cells constitute the principle components of the blood-testis barrier. 11. Leydig cells are present in the tissue. They can secrete . - 120 - . 12. The epididymis is divided into a head, body and tail. The head of the epididymis is formed by , the body and tail of the epididymis are formed by . Ⅲ. Questions 1. Describe the histological structure of seminiferous tubules. 2. Describe the structure and function of Sertoli cells. 3. Describe the components and function of the blood- testis barrier. 4. Describe the structure and function of Leydig cells. Ⅳ. Choose the correct answers for each question. 1. Which of the following descriptions is NOT about seminiferous tubules?( ) A. The seminiferous tubules are lined with seminiferous epithelium. B. The seminiferous epithelium rests upon a basement membrane. C. Around the basement membrane is to be found the limiting membrane (tunica propria) D. The limiting membrane is composed of collagen fibrils and myoid cells. E. Leydig cells are interposed between spermatogenic cells. 2. Which of the following cells are NOT included in the spermatogenic cells?( ) A. spermatogonia B. primary spermatocytes C. Sertoli cells D. spermatids E. spermatozoa 3. Which of the following cells are short-lived and divided quickly, thus few of them is seen in a section of a seminiferous tubule?( A. primary spermatocytes B. secondary spermatocytes C. spermatogonia - 121 - ) D. spermatids E. spermatozoa 4. Which of the following events is NOT occurred during spermiogenesis? ( ) A. formation of the acrosome B. condensation and elongation of the nucleus C. formation of the flagellum D. discharge of organelles and cytoplasm which are not required E. the third meiosis 5. Which of the following descriptions is NOT true about Sertoli cells?( ) A. Sertoli cells support, nourish, regulate and release germinal elements. B. Sertoli-Sertoli tight junctions constitute the principle component of blood testis barrier. C. Sertoli cells secrete testosterone. D. Sertoli cells phagocytose degenerated germinal cells and spermatogenic residual bodies. E. Sertoli cells secrete androgen-binding proteins 6. Which of the following structure is NOT included in the blood- testis barrier? ( ) A. endothelium and basement membrane of capillary B. limiting membrane C. basement membrane of seminiferous tubule D. between basement membrane and spermatogonia E. tight junction between adjacent Sertoli cells 7. Which of the following cells are transformed into spermatozoa? ( A. spermatogonia B. Sertoli cells C. Leydig cells D. spermatids - 122 - ) E. spermatocytes 8. Which of the following cells can secrete testosterone?( ) A. Leydig cells B. Sertoli cells C. spermatogonia D. spermatids E. spermatozoa 9. Which of the following description is NOT true about the epididymis. ( ) A. The ductus epididymis is lined with a simple columnar epithelium. B. The head of the epididymis is formed by efferent ductus. C. The body and tail are formed by the convolutions of the ductus epididymis. D. The epididymis has both absorption and secretion functions. E. The epididymis is divided into a head, body and tail. V. Choose the true or false by “ T”﹠“ F” 1. The seminiferous tubules are lined with a specialized stratified epithelium known as the seminiferous epithelium.( ) 2. The seminiferous epithelium consists of spermatogenic cells and Leydig cells.( ) 3. A primary spermatocyte can divided into two secondary spermatocytes by the first meiosis.( ) 4. The spermatids are haploid not only in terms of the number of chromosomes present but also in the amount of DNA.( 5. Each spermatid is divided into 2 spermatozoa.( ) ) 6. The primary spermatocytes are short-lived and divided quickly to produce secondary spermatocytes, few of them are seen in a section of seminiferous tubule.( ) 7. The Leydig cells are interposed between the spermatogenic cells.( - 123 - ) 8. The Sertoli cells have numerous lateral processes which form concavities surrounding differentiating spermatogenic cells.( 9. The Sertoli cells can secrete androgen.( ) ) 10. The Leydig cells are present in the interstitial tissue and can secrete testosterone.( ) ANSWERS Ⅰ. Definitions 1. spermatogenic cell Spermatogenic cells are a group of cells, including spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids and spermatozoa. 2. blood- testis barrier Blood-testis barrier consists of four layers: endothelium and basement membrane of capillary; basement membrane of the seminiferous tubule, limiting membrane and Sertoli cells tight junctions. 3. Leydig cell Leydig cells are present in the interstitial tissue. The cells usually occur in group. The cells are large and polygonal in shape. The nucleus is round with 1 or 2 prominent nucleolus and cytoplasm is acidophilic. Leydig cells exhibit typical ultrastructural features of steroid secretory cells. Leydig cells can secrete testosterone. Ⅱ. Fill in the blanks 1. seminiferous epithelium 2. basement membrane, spermatogenic cells, Sertoli cells 3. spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids and spermatozoa. 4. spermatogonia - 124 - 5. primary spermatocytes 6. secondary spermatocytes 7. spermatids 8. spermiogenisis, spermatozoa 9. Sertoli cells 10. tight junction 11. interstitial tissue, testosterone 12. efferent ductules, ductus epididymis Ⅲ. Questions 1. Describe the histological structure of seminiferous tubules. From interior to exterior, the wall of seminiferous tubules consists of seminiferous epithelium, basement membrane and limiting membrane. Seminiferous epithelium consists of spermatogenic cells and Sertoli cells. Spermatogenic cells are a group of cells, including spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids and spermatozoa. In the limiting membrane, collagen fibrils and myoid cells can be seen. 2. Describe the structure and function of Sertoli cells. Sertoli cells are columnar or pyramidal in shape and are interposed between spermatogenic cells. Such cells are characterized by an elongated nucleus which is often triangular in shape. A large prominent nucleolus is readily visible. Untrastrucurally, Sertoli cells contain abundant smooth endoplasmic reticulum and developed Golgi complexes. The cells have numerous lateral processes which form concavities surrounding differentiating spermatogenic cells. Sertoli cells have following functions: 1) support, protect, nourish, regulate and germinal elements; 2) participation in blood-testis barrier; 3) phagocytose degenerated germinal cells and spermiogenic residual bodies; - 125 - 4) secretion of androgen binding protein. 3. Describe the components and function of blood -testis barrier. Blood-testis barrier consists of four layers: endothelium and basement membrane of capillary; basement membrane of the seminiferous tubule, limiting membrane and Sertoli cells tight junctions. The barrier excludes the genetically different haploid germ cells from the immune system of the body and protects the seminiferous epithelium against auto-immune reaction. 4. Describe the structure and function of Leydig cells. Leydig cells are present in the interstitial tissue. The cells usually occur in group. The cells are large and polygonal in shape. The nucleus is round with 1 or 2 prominent nucleolus and cytoplasm is acidophilic. Leydig cells exhibit typical ultrastructural features of steroid secretory cells. Leydig cells can secrete testosterone. Ⅳ. Choose the correct answers for each question. 1. E 2. C 3. B 4. E 5. C 6. D 7. D 8. A 9. A V. Choose the true or false by “ T” ﹠“ F” 1. T 2. F 3. T 4. T 5. F 6. F 7. F 8. T 9. F 10. T Li jin-ru - 126 - FEMALE REPRODUCTIVE SYSTEM Ⅰ. Definitions 1. follicles of ovary 2. primordial follicle 3. ovulation 4. corpus luteum 5. menstrual cycle Ⅱ. Fill in the blanks 1. Primordial follicle is composed of one centrally located and one layer of flattened which is peripherally located. 2. The development of follicles can be divided into four stages: , , 3. Both and , . are termed growing follicles. 4. Cumulus oophorus is the important structure of follicle, which includes , , , . 5. In secondary follicle, the theca folliculi is differentiated into two layers: and and 6. . The former is rich in ; the latter has plenty of . days before the expected onset of the next menstruation ovulation occurred. During the process of ovulation, enzymes of the follicular fluid lead to a rupture of the follicular wall, and , together with the liquor folliculi are released into pelvic cavity. 7. The corpus luteum constitutes of two kinds of cells: and . 8. The corpus luteum can be classified into corpus luteum of (the oocyte is not fertilized) and corpus luteum of case of fertilization). - 127 - (in the 9. The endometrium of uterus can be divided into two main layers, a superficial and a deeper . 10. During menstrual cycle, three phases can be distinguished and , . Ⅲ. Questions 1. Describe the structure of a secondary follicle. 2. Describe the formation, structure and function of corpus luteum. 3. Describe the cyclic histological changes of endometrium during menstral cycle. Ⅳ. Choose the correct answers for each question. 1. Which of the following description is true about the primordial follicles? ( ) A. The primordial follicle consists of a primordial oocyte and a layer of flat follicle cells. B. The primordial follicle consists of a primary oocyte and a layer of flat follicle cells. C. The primordial follicle consists of a primary oocyte and a layer of cuboidal follicle cells. D. The primordial follicle separate from the surrounding connective tissue by zona pelllucida. E. The primordial follicle separate from the surrounding connective tissue by theca folliculi. 2. Which of the following follicles does NOT have zona pellucida? ( A. primadial follicle B. primaryfollicle C. secondary follicle D. growing follicle E. mature follicle - 128 - ) 3. Which of the following structure is NOT included in the secondary follicle? ( ) A. zona pellucida B. corona radiata C. cumulus oophorus D. theca folliculi E. secondary oocyte 4. Which of the following structure is NOT included in the mature follicle? ( ) A. zona pellucida B. corona radiata C. cumulus oophorus D. mature oocyte E. theca folliculi 5. When does ovulation occur?( ) A. the 28th day in a menstrual cycle B. the 7 th day in a menstrual cycle C. the 21th day in a menstrual cycle D. the 14th day in a menstrual cycle E. the 1th day in a menstrual cycle 6. Which of the following descriptions is NOT true about the corpus luteum? ( ) A. The corpus luteum continues to produce estrogen and progesterone during the whole process of pregnancy. B. The corpus luteum is formed after ovulation. C. The corpus luteum regressive to form fibrous corpus albicans about 10 days after ovulation, if the oocyte is not fertilized. D. The corpus luteum is vascularised. - 129 - E. The corpus luteum consists of two types of cell: granulose lutein cell and theca lutein cell. 7. The average length of a menstrual cycle is ( ) A. 21days B. 25days C. 28days D. 35days E. 38days 8. Which of the following descriptions is NOT true about the secretory phase of a menstrual cycle? ( ) A. The uterine glands become more coiled B. The basal layer of endometrium become thicker C. The helical artery become more coiled D. The secretory phase last for exactly 14 days. E. The uterine glands start to secrete V .Choose the true or false by “ T” ﹠“ F” 1. The medulla of ovary consists of follicles and corpus luteum in various stages.( ) 2. The primordial follicle is composed of a primary oocyte and a layer of flat follicle cells.( ) 3. The primary follicle is composed of a primary oocyte and several layers of flat follicle cells.( ) 4. In the secondary follicle, the secondary oocyte is located at the cumulus oophorus.( ) 5. In the secondary follicle, the granulosa cells surrounding the oocyte are arranged radially to form the corona radiate.( ) 6. The theca interna of growing follicles derived from follicle cells.( 7. Because of its endocrine function, the corpus luteum is richly vascularised.( ) - 130 - ) 8. Follicles can degenerate and perish only at the stage of secondary follicle.( ) 9. Fourteen days before the expected onset of the next menstruation, ovulation occurs.( ) 10. During menstrual phase, the basal layer of endometrium is sloughed.( ) ANSWERS Ⅰ. Definitions 1. follicle of ovary Each follicle is composed of a central oocyte and surrounding follicle cells. The follicles have four stages:primordial follicles, primary follicles, secondary follicles and mature follicles. 2. primordial follicle In primordial follicle, a primary oocyte is centrally located. The primary oocyte is surrounded by a single layer of squamous follicle cells, which are separated from the surrounding connective tissue by a basal lamina. 3. ovulation Fourteen days before the expected onset of menstruation, mature follicle is ruptured, the secondary oocytes with its zona pellucida, corona radiata and the liquor folliculi are released into the pelvic cavity, and this process is called ovulation. 4. corpus luteum Corpus luteum is a group of endocrine cells in ovary. Corpus luteum is composed of two types of cell: granulose lutein cells and theca lutein cells. Corpus luteum can secrete progesterone and estrogen. 5. menstrual cycle - 131 - In the sexually-mature, non-pregnant female the genital organs undergo periodically-recurring changes by the hormones of the hypothalamusadenohypophyseal-ovarian axis; such cyclic changes are termed the menstrual cycle. The average length of a menstrual cycle is 28 days. During a menstrual cycle, three typical phases can be distinguished: the menstrual phase, the proliferative and the secretory phase. Ⅱ. Fill in the blanks 1. primary oocyte, follicle cells 2. primordial follicle, primary follicle, secondary follicle, mature follicle 3. primary follicle, secondary follicle 4. primary oocyte, zona pellucida, corona radiata, follicle cells 5. theca interna, theca externa, theca cells, capillary, collagen fibers 6. 14, secondaary oocyte, zona pellucida, corona radiata 7. granulosa lutein cells, theca lutein cell 8. menstruation, pregnancy 9. functional layer, basal layer 10. the menstrual phase, the proliferative and the secretory phase. Ⅲ. Questions 1. Describe the structure of a secondary follicle. Secondary follicles develope from the primary follicles. A primary oocyte is located in the center of the follicles and become larger. Corona radiata: the granulose cells surrounding the oocyte are arranged radially to form the corona radiate. Zona pellucida: a homogeneous-like, eosinophilic membrane situated between primary oocyte and corona radiate. Antrum folliculi and liquor folliculi: layers of follicle cell gradually increase, small spaces appear between follicle cells and then small spaces - 132 - gradually fuse into a large cavity called antrum folliculi which is filled with liquor folliculi. Zona granulosa: follicle cells surrounding the follicular cavity form the follicle wall, which is called zona granulose Theca: Follicular stroma cells together with the connective tissue form a theca, which is differentiated into two layers; theca interna and theca externa. Theca interna is rich in capillaries and stroma cells. The stroma cells are polygonal or spindle in shape and with characteristics of steroid secreting cells. Theca externa is mainly composed of collagen fibrils. 2. Describe the formation, structure and function of corpus luteum. After ovulation, the ruptured follicles collapses, zona granulosa and theca folliculi folds into the cavity. During the following three days, the granulose cells are transformed into granulose lutein cells while the cells in the theca interna are transformed into theca lutein cells. Because of its endocrine function, the corpus luteum is richly vascularised. Corpus luteum can secrete progesterone and estrogen. Depending on whether fertilization, the corpus luteum can be divided into corpus luteum of menstruation, and corpus luteum of pregnancy. Corpus luteum can mainly secrete of estrogen, progesterone. 3. Describe the cyclic histological changes of endometrium during a menstrual cycle. A menstrual cycle is divided into menstrual phase, proliferative phase and secretory phase. Menstrual phase (days 1- 4 ): no fertilization takes place, corpus luteum degenerates, the production of estrogen and progesterone subsides, this cause vasoconstriction of helical arteries leading to ischemia, degeneration and necrosis of the functional layer. When the estrogen level rises again, vasodilation causes bleeding and the shedding of the necrotic tissue. - 133 - Proliferative phase (days 5-14): the functional layer regenerate from the cells of the basal layer. Stimulated by the developing follicles, all the endometrium structures begin to proliferate. The tubular glands are tubular initially and become coiled and their cells start to store glycogen. The helical arteries begin to sprout into the functional layer. The thickness of endometrium increases. Secretory phase (days 15-28): Caused by an increasing of production of progesterone by the corpus luteum, the uterine gland become more coiled and their cells accumulate glycogen. The helical arteries become more and more coiled; endometrium continues to thicken up to 5mm. Ⅳ. Choose the correct answers for each question. 1. B 2. A 3. E 4. D 5. D 6. A 7. C 8. B V. Choose the true or false by “ T” ﹠“ F” 1. F 2. T 3. F 4. F 5. T 6. F 7. T 8. F 9. T 10. F Li jin-ru - 134 - GENERAL HUMAN EMBRYOLOGY Ⅰ. Definitions 1. fertilization 2. cleavage 3. blastocyst 4. implantation 5. placental barrier 6. chorion 7. decidua 8. inner cell mass 9. capacitation 10. acrosome reaction 11. morula 12.cleft lip 13.cleft palate(main part) Ⅱ. Fill in the blanks 1. The movements of fetus can be felt by the mother during the . 2. If the intestinal loop does not go back the body of fetus by the 10th to 12th week, will occur in umbilicus of infant. 3. The placenta consist of and . 4. During the second week of gestation, the germ disc is composed of and . 5. By the 5th day after fertilization, the membrane around the blastocyst, called the , degenerates and disappears. While impla- ntation is began. 6. The cells of primitive pit proliferate, migrate cephalic between ectoderm and endoderm and form the which induces the formation of . - 135 - 7. The mesoderm are divided into three parts: and , , . 8. The formation of fold, fold and folds converts the flat embryonic disc into the shaped embryo. 9. Implantation takes place the outside of the uterus resulting in 10.The . is not obliterated in its proximal part and forms Meckel’s diverticulum. during the 3rd 11. Primordial germ cells are originated from week. 12. By the end of week, the external appearance of embryo looks like human. By the full-term the fetus is more length, more cm in in weight. 13. The external genitalia of fetus are recognizable in the 14. The months. at the cranial end of the disc consists of a small region of tightly adherent ectoderm and endoderm cells that represents the future opening of the oral cavity. 15. The divides the lateral plate mesoderm into two layers: (1) a layer and (2) a layer. 16. The bilaminar germ disc is connected to the trophoblast by the 17. If . does not close its lumen, the fetal urine is leaked from the newborn’s umbilicus. 18. The is incorporated into the body and forms the primitive gut. The connects with by the vitelline stalk (duct). 19. Fetal membranes include the following: , , , 20. The umbilical cord at full term contains ( artery ) and umbilical veins ( vein ). - 136 - , . umbilical arteries 21. During the development of stomach it rotates ______degree clockwise around its longitudinal axis (viewed from the cranial end). 22. Pharyngeal apparatus includes ; and ; . Ⅲ. Questions 1. Briefly describe the formation of the embryonic mesoderm 2. Briefly describe the structure and function of placenta 3. Briefly describe what each germ layer normally contributes to the tissues or organs of embryo 4. Briefly describe the formation of the primitive streak 5. Briefly describe the formation of the neural tube Ⅳ. Choose the correct answers for each question 1. Before spermatozoa achieve the ability to fertilize the oocyte, they must undergo ( ) A. spermatogenesis B. meiosis C. mitosis D. capacitation E. cleavage 2. The number of chromosomes of gametes is halved during ( ) A. mitotic division B. the first meiosis C. the second meiosis D. spermiogenesis E. fertilization 3. After the fertilized ovum divides from one cell into 12 to 16 cells, it is known as a/an ( ) A. blastocele B. blastocyst - 137 - C. embryoblast D. trophoblast E. morula 4. Each cell of the zygote, which becomes smaller with each division, is termed a( ) A. blastocele B. blastocyst C. blastomere D. blastula E. morula 5. Where and when does fertilization normally occur? ( ) A. Ovary, immediately after ovulation B. Vagina, within 12 hours after ovulation C. Internal os of the uterus, within 1 day after ovulation D. Ampulla of the oviduct, within 1 day after ovulation E. Anterior wall of the uterine body, within 2 days after ovulation 6. The blastocyst is completely embedded in the endometrial stroma by days( ) A. 1-2 B. 3-4 C. 5-6 D. 8-9 E. 11-12 7. The most characteristic event that occurs during the third week is( A. the appearance of endodermal cells B .the formation of the primitive streak C. the appearance of the amniotic cavity D. the formation of the primitive yolk sac E. all of the above - 138 - ) 8. The epiblast layer, after the intraembryonic mesoderm is formed, is termed the ( ) A. trophoblast B. hypoblast C. endoderm D. ectoderm E. amnion 9. Until the end of the fourth week, intraembryonic mesoderm is actively formed from the( ) A. primitive streak B. notochord C. trophoblast D. extraembryonic mesoderm E. endodermal cells 10. The neural tube is formed from the ( ) A. notochord B. mesenchyme C. amniotic ectoderm D. intraembryonic paraxial mesoderm E. the thickening of ectoderm at the cephalic end of the embryo 11. In human embryo the first primordial germ cells are found in the ( A. surface ectoderm B. metanephros C. yolk sac D. allantois E. mesonephros 12. A chorionic villus does NOT contain ( A. maternal blood vessels B. fetal blood vessels - 139 - ) ) C. syncytiotrophoblast cell layer D. loose connective tissue E. cytotrophoblast layer 13. The constituent cells of the somite may differentiate into all of the following tissues EXCEPT( ) A. epidermis B. dermis C. cartilage D. muscle E. bone 14. The intermediate mesoderm is the progenitor of the ( ) A. spinal cord B. deep fascia C. genital ducts D. visceral muscle E. sympathetic ganglia 15. The neural tube is produced under induction of the ( ) A. amnion B. yolk sac C. notochord D. somite E. primitive streak 16. Which of the following statements about the lateral mesoderm is FALSE? ( ) A. Intraembryonic coelom (cavity)forms in it B. It divides into the visceral layer and parietal layer C. The visceral laye covers the ectoderm D. Somatic mesoderm develops into the bones of the body wall E. Abdominal cavity is derived from the intraembryonic coelom(cavity) - 140 - 17. The endodermal germ layer ultimately gives rise to all of the following EXCEPT ( ) A. the epithelial lining of the bladder B. the epithelium of the digestive tract C. the alveolar cells of the lungs D. the parenchyma of the liver E. the parenchyma of the spleen 18. Which of the following cells does NOT have the correct number of chromosomes? ( ) A. zygote (44 + 2 sex chromosomes) B. mature ovum (22 + 1 sex chromosome) C. spermatogonium (44 + 2 sex chromosomes) D. first polar body (22 + 1 sex chromosome) E. primordial germ cell (22 + 1 sex chromosomes) 19. What is the lowest percentage of morphologically normal sperm in a semen sample compatible with normal fertility? ( ) A. 10% B. 20% C. 40% D. 60% E. 80% 20. A lady of 32 becomes pregnant. The ovum, which was fertilized, was probably derived from an oogonium ( ) A. 2 weeks ago B. 2 months ago C. 20 years ago D. more than 30 years ago E. at any time since puberty 21. The cloacal membrane is composed of the( - 141 - ) A. ectoderm B. endoderm C. mesoderm D. ectoderm and endoderm E. ectoderm, mesoderm and endoderm 22. Which of the following are NOT derived from the neural crest? ( A. spinal cord B. spinal ganglia C. autonomic ganglia D. adrenal medulla E. the parafollicular cells of the thyroid 23. The cells in the amniotic fluid would have which of the following origins?( ) A. fetus only B. mother only C. mother and father D. fetus and mother E. mother, father and fetus 24. The placenta is an endocrine gland, which secretes ( A. chorionic gonadotropin B. progesterone C. estrogen D. human placental lactogen E. all of the above 25. Fetal membrane does NOT include the ( A. amnion B. chorion C. placenta D. umbilical cord - 142 - ) ) ) E. yolk sac 26. The intervillous spaces contain ( ) A. fetal blood B. maternal blood C. a mixture of maternal and fetal blood D. the blood with a high CO2 content E. the blood with a low oxygen content 27. Human chorionic gonadotropin is first produced by syncytiotrophblast ( ) A. within 1 week of fertilization B. 2 weeks after fertilization C. 4 weeks after fertilization D. 2 months after fertilization E. 4 months after fertilization 28. Completion of the second meiosis of the oocyte occurs during the ( A. fertilization B. ovulation C. cleavage D. secondary follicle E. matrue follicle 29. The oocyte is fertilized ( ) A. prior to the first maturation division B. during the first maturation division C. between the first and second maturation division D. during the second maturation division E. after the second maturation division 30. The specific receptors (ZP3) for sperm are located on/in the ( A. corona radiate B. zona pellucida - 143 - ) ) C. cell membrane of the oocyte D. cytoplasm of the oocyte E. nucleus of the oocyte 31 .Which of the following statements about rotation of the midgut loop are true when viewed from the front? ( ) A. The midgut loop undergoes a total rotation of 270°counterclockwise. B. The midgut loop a total rotates 180°clockwise. C. The midgut loop a total rotates 270°clockwise. D. The midgut loop undergoes a total rotation of 180°counterclockwise. E. The midgut loop rotates only 90°counterclockwise. 32. A newborn infant coughs and regurgitates its milk when fed, and has respiratory distress when it cries. What congenital malformations would you consider in the diagnosis of the infant’s problems?( ) A. treacheal atresia B. esophageal atresia or tracheoesophageal fistula C. the agenesis of lungs D. the agenesis of the heart E. hyaline membrane disease ⅤChoose the true or false by “ T” ﹠“ F” 1. The zona reaction prevents penetration of an oocyte by more than one sperm (polyspermy).( ) 2. Test- tube- babies grow up in vitro throughout development. ( ) 3. The end in which the primitive streak appears, is the cephalic end of the germ disc. ( ) 4. The inner cell mass of the blastocyst will develop into the embryo proper. ( ) 5. The hindgut, caudal part of the primitive gut, remains in connection with the yolk sac by the vitelline stalk before six weeks of gestation. ( - 144 - ) 6. The ectoderm, mesoderm and endoderm are all derived from the epiblast cells. ( ) 7. In the testis, spermatogonia, Sertoli cells and interstitial cells of Leydig are all developed from the intermediate mesoderm. ( ) 8. Fetal membranes possess functions of protection, nutrition and production of hormones.( ) 9. Extraembryonic mesoderm covers the yolk sac, amnion and cytotrophoblast. ( ) 10. In the placenta the maternal and fetal blood are mixed to promote the substance exchange.( ) 11. The two medial nasal prominences fuse to form the philtrum. ( ) 12. The cleft palate(main part) results from a lack of fusion of palatine shelves. ( ) ANSWERS Ⅰ. Definitions 1. fertilization It is a series of processes that a female gamete (oocyte) and a male gamete(sperm) contact and fuse to form a single cell---- zygote 2. cleavage The zygote undergoes a series of mitotic divisions, increasing the numbers of cells. These cells, which become smaller with each cleavage division, are known as blastomeres. 3. blastocyst About 4 days after fertilization, blastomeres in number reach more a hundred cells, the morula begins to present intercellular spaces and then become a single cavity, filling with the fluid. At this time the embryo is called a blastocyst. - 145 - The structures of blastocyst: polar trophoblast, trophoblast, inner cell mass, blastocyst cavity 4. implantation The blastocyst implants in the endometrium along the anterior or posterior wall of uterus. It begins in the 5th -6th day; finishes in the 11th-12th day. 5. placental barrier Separates the maternal and fetal blood in placenta At the beginning: endothelium of fetal vessels connective tissue of villi cytotrophoblast syncytiotrophoblast After the 4th month: endothelium of fetal vessels syncytium 6. chorion Chorion consists of the trophoblast (cytotrophoblast & syncytiotrophoblast) and extraembryonic mesoderm. Two parts: chorion frondosum; chorion leave. 7. decidua The endometrium after the implantation is called decidua. It is divided into decidua parietalis, decidua basalis, decidua capsularis. 8. inner cell mass A small cluster of cells, located at one side in the blastocyst , called inner cell mass which initiate to form the embryo ( epiblast and hypoblast). 9. capacitation Capacitation is a period of conditioning in the female reproductive tract that in the human lasts approximately 7 hours. Much of this conditioning, which occurs in the uterine tube, entails epithelial interactions between the - 146 - sperm and mucosal surface of the tube. During this time a glycoprotein coat and seminal plasma proteins are removed from the plasma membrane that overlies the acrosomal region of the spermatozoa. Only capacitated sperm can pass through the corona cells and undergo the acrosome reaction. 10. acrosome reaction Which occurs after binding to the zona pellucida, is induced by zona proteins. This reaction culminates in the release of enzymes needed to penetrate the zona pellucida, including acrosin and trypsin-like substances. 11. morula Approximately 3 days after fertilization, cells of the compacted embryo divide again to form a 16-cell morula (mulberry).The morula just enters the uterin cavity. 12. cleft lip It occurs when the median nasal prominence fails to fuse with the maxillary prominence. 13. cleft palate(main part) The cleft palate (main part) results from a lack of fusion of palatine shelves. Ⅱ. Fill in the blanks 1. 16th week 2. congenital umbilical hernia 3. decidua basalis, chorion frondosum 4. epiblast, hypoblast 5. zona pellucida 6. notochord, neural tube . 7. paraxial (somites), intermediate, lateral plate mesoderm 8. head, tail, lateral, C (cylindrical) - 147 - 9. ectopic pregnancy 10. vitelline stalk 11. endoderm 12. 8th, 50 (CHL), 3400g 13. 3rd 14. buccopharyngeal membrane 15. intraembryonic cavity, parietal, visceral 16. connecting stalk 17. urachus 18. endoderm, midgut, yolk sac 19. chorion, amnion, yolk sac, allantois, umbilical cord 20. two umbilical arteries, one umbilical vein 21. pharyngeal arches, pharyngeal grooves, pharyngeal sacs, pharyngeal membranes 22. 90 Ⅲ. Questions 1. Briefly describe the formation of the embryonic mesoderm . At 3rd week after fertilization, the primitive streak appears on the surface of the epiblast. Primitive streak cells invaginate into the epiblast and hypoblast to form new layer---- mesoderm. While epiblast changes name as ectoderm; hypoblast are replace by new cells---endoderm. 2. Briefly describe the structure and function of placenta Disc shaped, two surfaces----maternal and fetal surfaces Structures: Maternal decidua basalis and fetal chorion frondosum. The placental barrier separates the maternal blood from fetal blood Functions: exchange gasses, nutrients and waste products; secrete hormones - 148 - 3. Briefly describe what each germ layer normally contributes to the tissues or organs of embryo Ectoderm Neural tube--- brain and spinal cord Neural crest--- peripheral never system Superficial ectoderm--- epidermis of skin Mesoderm Paraxial mesoderm (somite)--- mesenchyme, muscle, bone, dermis of skin Intermediate mesoderm --- urinary system, gonads Lateral plate mesoderm --- parietal layer, visceral layer embryonic cavity Endoderm primitive gut --- epithelium of digestive tract, respiratory tract, ect. 4. Briefly describe the formation of the primitive streak About the 15th day after fertilization, on the surface of the epiblast, a cellcord, which is proliferated by the epiblast, appears along the longitudinal midline on either side of the germ disc, known as the primitive streak. Once the cells have invaginated, some displace the hypoblast, creating the embryonic endoderm, and others come to lie between the epiblast and newly created endoderm to form mesoderm. Cells remaining in the epiblast then form ectoderm. 5. Briefly describe the formation of the neural tube At the beginning of the third week of development, the ectodermal germ layer has the shape of a disc that is broader in the cephalic than the caudal region. The notochord induces the overlying ectoderm to thicken and form the neural plate. Cells of the plate make up the neuroectoderm and their induction represents the initial event in the process of neurulation. Once induction has occurred, the elongated, slipper-shaped neural plate gradually expands toward the primitive streak. By the end of the third - 149 - week, the lateral edges of the neural plate become more elevated to form neural folds, and the depressed mid-region forms the neural groove. Gradually, the neural folds approach each other in the midline, where they fuse. Fusion begins in the cervical region (fifth somite) and proceeds cranially and caudally. As a result, the neural tube is formed. Until fusion is complete, the cephalic and caudal ends of the neural tube communicate with the amniotic cavity by way of the cranial and caudal neuropores, respectively. Closure of the cranial neuropore occurs at approximately day 25, whereas the posterior neuropore closes at day 27. Neurulation is then complete, and the central nervous system is represented by a closed tubular structure with a narrow caudal portion, the spinal cord, and a much broader cephalic portion characterized by a number of dilations, the brain vesicles. Ⅳ. Choose the correct answers for each question 1. D 2. B 3. E 4. C 5. D 6. E 7. B 8. D 9. A 10. E 11. C 12. A 13. A 14. C 15. C 16. C 17. E 18. E 19. E 20. D 21. D 22. A 23. A 24. E 25. C 26. B 27. B 28. A 29. D 30.B 31. A 32. B ⅤChoose the true or false by “ T” ﹠“ F” 1. T 2. F 10. F 11.T 3. F 4. T 5. F 6. T 7. F 8. T 9. T 12.T Liang yu - 150 -