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SUBJECT: ANATOMY & PHYSIOLOGY 1 BIOL 2401 Chapter 5 - Tissues Tissue Types: 1. Overview of tissues There are 4 types: A. Epithelium B. Connective C. Muscle D. Nervous II. Epithelium. A. Characteristics: i. tightly packed cells ii. cells have polarity - apical end (surface) and basal end (basement membrane) iii. no extracellular matrix (ECM) iv. little blood supply v. highly innervated (nerves) vi. high regeneration capacity B. Classification; i. How many layers? Simple - 1; or stratified ≥ 2 ii. Shape of cell a. flat -squamous b. square(cube) - cuboidal c. tall slender- columnar C. Examples- see Table 1 p. 5. (I made it super easy !) D. Glands (Skip simple vs compound glands) i. Endocrine -secrete into blood, no ducts, action is distant. ex. thyroid ii. Exocrine - secrete onto surface via a duct, action local. ex. sweat glands a. Secretory part called acinus; tube for delivery is a duct. b. Merocrine - secrete by exocytosis (vesicles). ex. pancreas, salivary, sweat c. Apocrine - secrete by pinching off some cytoplasm. ex. mammary, sweat d. Holocrine - secretes by whole cell rupturing. ex. oil (sebaceous) glands PAGE 1 OF 6 DR. DAVID L. COX SUBJECT: ANATOMY & PHYSIOLOGY 1 BIOL 2401 III. Connective Tissue A. Characteristics: i. MOST abundant and diverse of 4 groups ii. loosely packed cells- cells rarely touch iii. lots of extracellular matrix (ECM) iv. large blood supply in most, but not all B. Functions - examples: i. support- bones, cartilage ii. protection - bones, fat tissue (cushion) iii. immunity- macrophages, plasma cells, T-cells, etc iv. bind organs - tendons & ligaments v. storage- fat (adipose), Ca and phosphate in bones. C. Classification (Groups) see Table 5.8, p166 D. Connective tissue Proper i. Loose Connective Tissue (lots of ground substance) a. Areolar i) lots of ECM, ii) fibers -collagen, elastin, reticular. Collagen one of the most abundant proteins in the body. iii) collagen made by fibroblasts (very abundant) iv) lots of ground substance = water + proteins v) adipocytes, and macrophages also resident cells vi) location- dermis of the skin b. Adipose (fat) i) stores fat for energy ii) resident cells adipocytes iii) also insulates and cushions some organs. iv) location- subcutaneous layers of the skin, around eyeball and other organs. c. Reticular i) support of lymphatic organs ii) provides the stroma of spleen, thymus, lymph nodes, etc ii) Dense Connective Tissue (little ground substance) PAGE 2 OF 6 DR. DAVID L. COX SUBJECT: ANATOMY & PHYSIOLOGY 1 BIOL 2401 a. Dense regular i) all the fibers parallel and aligned (lasagna noodles) ii) designed for stress in 1 direction iii) location - tendons and ligaments b. Dense irregular i) fibers going in every direction ii) designed for stress in many directions iii) location - dermis of skin, periosteum of bones, cartilage c. Elastic connective tissue i) high concentration of elastic fibers ii) designed for stretching and recoil iii) location - lines blood vessels, and trachea E. Supportive Connective tissue i. Cartilage (low blood supply- avascular) a. forms fetal skeleton, provides support b. resident calls called chondrocytes; in spaces called lacunae. c. 3 types: i) hyaline cartilage - most abundant; locations: ends of bones that form joints; trachea. ii) fibrocartilage -has lots of collagen fibers-tough- vertebral discs. iii) elastic cartilage- lost of elastic fibers, ear lobe and epiglottis. ii. Bone (much blood supply- vascular) a. Functions: forms skeleton, provides support, stores Ca and phosphate, makes blood cells b. resident calls called osteocytes in spaces also called lacunae. c. basic unit of bone is the osteon; consists of concentric rings (lamellae) surrounding a central canal that has blood vessel and nerve. d. inside bones are stem cells that have hemopoietic (blood cell formation) activity F. Fluid Connective tissue i. Blood (comes from bones) a. provides transport (O2, CO2, nutrients, waste); and immunity b. Some key cells: PAGE 3 OF 6 DR. DAVID L. COX SUBJECT: ANATOMY & PHYSIOLOGY 1 BIOL 2401 i) macrophages - major phagocyte that engulf foreign organisms and debris. Neutrophils are the other major phagocyte. ii) lymphoctyte - B-cells become plasma cells and secrete antibodies: T- cells also fight virus infected cells and tumors. iii) erythrocytes- most abundant, carry O2, CO2, iv) basophil (Mast) cells secrete heparin and or histamine which can constrict or dilate blood vessels. ii. Plasma (comes from blood) a. plasma is blood without all the cells; primarily the liquid portion. b. lymph is derived from plasma that leaks into tissues, is collected by the lymphatic system and returned to the bloodstream. IV. Muscle Tissue A. Characteristics: i. can contract ii. some voluntary, some involuntary iii. 3 types: a. Skeletal muscle - (moves bones) i) majority of muscle tissue. ii) voluntary iii) striated cells iv) multiple nuclei b. Cardiac muscle - (only in the heart- pumps blood) i) involuntary ii) striated, branched cells iii) has intercalated discs a special gap junction between cells iv) 1 or 2 nuclei c. Smooth muscle - (moves or propels materials) i) involuntary ii) not striated iii) walls of hollow organs like the large and small intestines, stomach, bladder, walls of blood vessels, etc V. Nervous Tissue A. Characteristics: i. can conduct and receive impulses PAGE 4 OF 6 DR. DAVID L. COX SUBJECT: ANATOMY & PHYSIOLOGY 1 BIOL 2401 ii. Neurons - conducting cells. a. dendrite receives impulse. b. axon carries it to another neuron, muscle, or gland cell. c. nucleus and organelles in the cell body of the neuron iii. Glial cells a. support neurons - example Schwann cells. VI. Organs A. Made of multiple types of tissues. B. Example: stomach has epithelium, connective tissue, muscle and nervous tissue. VII. Classification of body membranes Epithelial: simple organs, epithelium, and connective tissue components. A. Cutaneous (the scan): epidermis (stratified Squanto 7 PM) underlined by the dermis (dense connective tissue); protects body surface. B. Mucous: apathy or sheet underlain by lamina propria (Arielle or connective tissue) called on lines body cavities open to the exterior. C. Serous: simple squamous epithelium resting on a scant connective tissue layer; lines the ventral body cavity. VIII. SKIP Tissue development and Aging PAGE 5 OF 6 DR. DAVID L. COX SUBJECT: ANATOMY & PHYSIOLOGY 1 BIOL 2401 TABLE 1 Types of Epithelial Cells Epithelium Functions Locations diffusion, filtration lung alveoli, lines blood vessels Simple cuboidal absorption, secretion kidney tubules, secretory part most exocrine glands Simple columnar absorption, secretion lines digestive tract, secretion, move mucous bronchioles, fallopian tubes protection very rare - male urethra secretion, move mucous trachea Stratified squamous protection mouth, larynx, esophagus Stratified squamous, keratinized protection epidermis Stratified cuboidal protection ducts of most exocrine glands Stratified columnar protection salivary glands distention - stretching bladder, uterus Simple squamous Simple columnar, ciliated Pseudostratified Pseudostratified, ciliated Transitional PAGE 6 OF 6 DR. DAVID L. COX