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Workbook: Body Tissues Learning outcomes Name the four principle tissue types Briefly describe the main functions of each type of tissue Discuss the general characteristics and features of muscle tissue, nervous tissue, epithelial tissue and connective tissue Describe the difference between simple and stratified epithelium Compare and contrast the structure of squamous, cuboidal, columnar, ciliated, glandular, transitional, and stratified epithelial tissue (giving examples of where in the body each type can be found) Relate the structure of each epithelial type to its function. State the main function of mast cells, plasma cells, macrophages, fibroblasts, fat cells Outline the structure, function, and location of areolar tissue, adipose tissue, fibrous tissue, elastic tissue, hyaline cartilage, fibrocartilage, elastic fibrocartilage, bone List and give examples of the four principle types of membrane found in the body Name the tissues in the diagrams above. Primary Tissues The body is composed of 4 principle tissue types. These are: MUSCLE NERVOUS EPITHELIAL CONNECTIVE Clinical note: The study of tissues is called histology Organs Organs are composed of at least two primary tissues List four ‘vital’ organs: BRAIN, HEART, KIDNEYS,LIVER Systems Organs that are located in different regions of the body and perform related functions make up a system List the main body systems: Respiratory, cardiovascular, Musculoskeletal, etc etc Muscle Tissues Main Function: Muscle tissue is responsible for MOVEMENT Specialized for contraction There are 3 different types of muscle tissue. These are: SKELETAL CARDIAC SMOOTH Skeletal Muscle Produce skeletal movement Are these movements Voluntary or Involuntary ? Are the muscles Striated or Smooth ? Are they attached to bones by Tendons or Ligaments? Muscle fibers are arranged in bundles, fibers are arranged in parallel. Muscle cells have a Sarcolemma and Sarcoplasm. What are the equivalent structures in a ‘typical’ cell? Plasma membrane and cytoplasm What are the ‘thinnest’ structures labelled in the diagram? Tendons?, Muscle fibers?, Myofibrils?, or Filaments? (further detail on muscle to follow) Cardiac Muscle Striated, found only in the Heart Using the Language of Science workbook, look up MYOCARDIUM Heart Muscle Myocardial cells are interconnected to form a ‘continuous fabric’ (further detail on the heart to follow) Smooth Muscle Are the muscles Striated or Smooth? Are the movements of smooth muscle, Voluntary or Involuntary? What two organs are in the diagram below? Digestive Tract and Eye What sort of nerves control smooth muscle? Autonomic As well as the smooth muscle cells, what other cell is common to both the single unit smooth muscle and the multi-unit smooth muscle? Neurone Where else in the body would you find smooth muscle? Bladder, Ureters, Blood vessels, Bronchioles etc Nervous Tissue Main Function: Nervous tissue initiates and transmits NERVE IMPLULSES that co-ordinate body activities Neurones (nerve cells) Specialized for action potential conduction. Complete the following table: Feature Function Dendrites Receive input Cell body Contains the Nucleus Nucleus Directs cell’s activities Axon Conducts nerve impulses Myelin Sheath Increases speed of nerve impulse Supporting cells are called neuroglia Main Function of neuroglia is to Provide anatomical and functional support for nerve cells Epithelial Tissue Main Function: Epithelial tissue or epithelium acts as Protective shield It is found as the outer layer of the skin, lining organs, vessels etc, forms membranes Epithelial tissue can add new cells when cells are old or worn out Rate of renewal varies according to location Can also be a secretory tissue Epithelial tissue may be: Simple, consisting of single layer of cells Stratified, consisting of multiple layers of cells General characteristics of Epithelial Tissues Epithelial cells are tightly packed in continuous sheets to protect underlying tissue, or to form barriers between systems Cells are held in place by adhesions formed between plasma membranes of adjacent cells The cells vary in shape and arrangement according to their function, (this forms the basis for classifying epithelial tissue) Cells are anchored to connective tissue by a thin layer called the …basement… membrane. This provides elastic support and acts as a partial barrier for diffusion and filtration Epithelial tissue is avascular (meaning …do not have a blood supply…) Oxygen and nutrients diffuse through the basement membrane from capillaries in the underlying connective tissue Structure, function and location of Epithelial Tissues: Simple 1. Squamous Describe the cells in the diagram. ..Thin, flat, fit closely together… ..Sit on basement membrane… …………………………………………… Function: ..Diffusion……… Location: …Alveoli, Blood Vessels etc…. 2. Cuboidal Describe the cells in the diagram. ..Cube shaped, cells fit closely together… ..Sit on basement membrane…. …………………………………………… Function: …Secretion, Absorption, Excretion…. Location: …Renal tubules, some glands. 3. Columnar Describe the cells in the diagram. …Rectangular shaped, microvilli, goblet cells… …Sit on basement membrane… …………………………………………… Function: …Absorption, secretion of mucous. Location: …Lining of GI tract. 4. Ciliated Describe the cells in the diagram. …As above, with cilia… …………………………………………… Function: …Cilia propel tube contents……. Location: …Respiratory passages, ……. ….Uterine tubes… Structure, function, location of Epithelial Tissues: Stratified 5. Transitional Several layers of pear shaped Cells on a basement membrane Function: Allows for stretching Location: Urinary bladder Non Keratinised Stratified Several layers of cells Function: Protection Location: Found on Wet…surfaces… subject to wear and tear, but protected from drying out. E.g. …conjunctiva, oesophagus… …lining of mouth……………………….… Keratinised stratified …Several….layers of cells Surface layer consists of …dead.. epithelial cells to which …keratin... has been added. Function: .Forms tough waterproof …… .. protective layer, prevents.. …drying out of underlying cells… ……………………………………….. Location: Found on Dry…surfaces subject to wear and tear. E.g. …skin,……………….…… …hair, nails……………… Glands A gland is an organ specialised to produce a substance that is sent out to other parts of the body The active cells of many glands are epithelial cells Glands are divided in to two categories based on how they release their secretions Exocrine Glands Secretions are released through ..ducts….. Examples: …tear glands, sweat glands, prostate gland……. …GI glands…………………………... Endocrine Glands Secrete ..hormones………… directly into …the blood stream……… Affect ..Target………… tissues May be discrete organs: Examples: …pituitary gland, thyroid gland…. ………………………………………………... Connective Tissue Main Function: Connective tissue forms the supporting fabric of all parts of the body, and is the most abundant, and widely distributed body tissue Consists of two main elements: Cells and a Matrix (see diagram below) Connective tissue: Cells Connective tissue has different cell types that make it up [All the cells to complete the below list are contained within the diagram] …Fibroblasts……………….. produce collagen and elastic fibres …Macrophages…………….. actively phagocytic …Plasma cells………………. synthesise and secrete antibodies …Mast cells…………………. produce histamine …Fat cells………………..…. abundant in adipose tissue Matrix is the non living material that exists between connective tissue cells and contains various amounts of water, fibers, and hard minerals A Matrix consists of fibres and ground substance (space between fibres and cells) The various connective tissues differ in terms of hardness (depending on composition of the Matrix) Connective tissue is categorised according to physical properties and may be: Liquid (Blood) or Soft or Fibrous or Hard Most Connective tissue is highly vascular, and supplied with nerve endings Soft connective tissue Areolar tissue (loose) Most common type of connective tissue Contains cells and fibres in a loose, jelly like background material Function: Connects and supports other tissues, provides Elasticity and tensile strength Location: Almost everywhere. Found in membranes around organs and vessels, between muscles, under the skin Question: What fibres are contained in areolar tissue? …Collagen fibres / Elastic fibres………………………… Adipose tissue (loose) Each adipose cell (adipocyte) has its cytoplasm stretched around a globule of fat Location: widespread Question: What is the function of Adipose tissue?? …Reserve energy supply,………….…. ……insulation………………………. ……………………………………………… ………………………………………………. Fibrous connective tissue Fibrous tissue ca be can be regular or irregular (see diagrams) Very dense, contains large numbers of fibres that give it strength and flexibility. What are the fibres in the tissue diagrams opposite called?…collagen fibres………. Some types of Fibrous connective tissue contain many elastic fibres, allowing stretch and return to original length What does dense regular connective tissue contain more of? …collagen fibres…………….. Function: Forms the capsules surrounding certain organs Facilitates movement Forms the Elastic tissue in vocal chords, large arteries, respiratory tract Location: Tendons and ligaments (dense regular) Kidney, liver and glandular capsules (dense irregular) Hard connective tissue: Cartilage Strong and flexible Question: What cells produce cartilage? …chondrocytes……………….. Question: What are the 3 types of cartilage (one type is illustrated in the diagram opposite)> …Fibroblasts………………………. …Hyaline………………………………. …Elastic…………………………………. Function: Shock absorber, and also reduces friction between joints Location: Hyaline cartilage is found …end of long bones….. Fibrocartilage is found …between vertebrae…….…….. Elastic cartilage is found …larynx, ears…………. Hard connective tissue: Bone Produced in concentric layers or lamellae around blood vessels. Bone is made of oseous tissue, (similar in structure to cartilage). The tissue becomes impregnated with calcium and phosphorous salts. Question: What cells produce bone? …osteoblasts……… Question: What are mature bone cells called? …osteocytes………………… Function: Support, Movement, Protection, Energy storage, Production of red and white blood cells Membranes Membranes are thin sheets of tissue, there are two main types: Epithelial membranes and Connective tissue membranes Membranes may cover a surface, line a cavity, serve as a dividing partition, or anchor an organ Epithelial membranes Mucous membranes (mucosa): Line tubes and other body spaces that open to the environment e.g. digestive, respiratory, reproductive tracts Secrete mucous, a sticky fluid Some are ciliated Serous membranes (serosa): Cover organs- Heart (pericardium), lungs (pleura), abdomen (peritoneum), and may also be attacked to cavity walls Do not connect with the outside of the body Secrete serous fluid, allows organ to move with reduced friction Cutaneous membranes (the skin): Has an outer layer of epithelium Highly complex, and will be discussed in much greater detail later on Connective tissue membranes Synovial membranes: Line joint cavities Secrete synovial fluid, that lubricates joints Line small cushioning sacs near joints called Bursae Other connective tissue membranes include: Meninges surround the brain and spinal cord Fascia fibrous bands that or sheets that support organs and hold them in place Periosteum surrounds bones Perichondrium surrounds cartilage