1. Body Tissues

2. Tissues - groups of cells that are similar in structure and function Four tissue types and general function: *EPITHELIUM - covering *CONNECTIVE - support MUSCLE - movement NERVOUS - control

3. epithelial tissue (epithelium) the lining, covering, and glandular tissue of the body protection (skin, respiratory tract), absorption (stomach, small intestine), filtration (kidneys), and secretion (glands- sweat, oil, digestive enzymes, mucus)

4. special characteristics of epithelium form continuous sheets, joined by desmosomes and tight junctions apical surface= free surface or edge exposed to body’s exterior or cavity of internal organ basement membrane =lower surface of epithelium, secreted by cells no blood supply, depend on diffusion from capillaries for food and oxygen regenerate themselves easily

5. classification of epithelium by cell arrangement (simple, stratified) and cell shape (squamous, cuboidal, columnar) simple = one cell layer stratified = more than one cell layer squamous = flattened like fish scales cuboidal = cube-shaped like dice columnar = shaped like columns

6. simple epithelia simple squamous - single layer, filtration, rapid diffusion (alveoli, capillaries, serous membranes) simple cuboidal - single layer on basement membrane (glands and ducts, kidney tubules and surface of ovaries) simple columnar - single layer, tall close together (lines digestive tract from stomach to anus) pseudostratified (ciliated) columnar - appear at different heights above basement membrane, absorption, secretion (lines respiratory tract)

7. stratified epithelia stratified squamous - several layers, receives frequent friction (esophagus, mouth, outer skin) stratified cuboidal/columnar - two cell layers, cuboidal at surface, fairly rare (ducts of large glands) *not in table transitional - modified stratified squamous, change shape, subject to stretching (urinary bladder, ureters)

8. types of epithelium (picture pg 80)

9. glandular epithelium gland=one or more cells that secrete a product duct = channel leading from a gland to epithelial surface endocrine gland - ductless, secrete hormones directly into blood vessels (thyroid, adrenals, pituitary) exocrine glands - have ducts, excrete product to internal or external surface (sweat, oil, liver, pancreas)

10. glands (picture)

11. connective tissue most abundant and widely distributed tissue most are well vascularized (good blood supply) tendons and ligaments have a poor blood supply cartilages are avascular made up of many cell types plus nonliving substances called the extracellular matrix

12. extracellular matrix Made of two elements in varying amounts: ground substance - water, adhesion proteins, large polysaccaride molecules fibers - collagen, elastic, reticular

13. types of connective tissue bone (osseous tissue) - rocklike hardness, calcium salt matrix, protection, support (skull, bones) hyaline cartilage - collagen fibers, rubbery matrix (larynx, attaches ribs to sternum, ends of bones, fetus skeleton) fibrocartilage - chondrocytes and collagen fibers, highly compressible (between vertebrae) elastic cartilage - elasticity (supports external ear)

14. connective tissues dense connective (dense fibrous) -collagen fibers, fibroblasts, ropelike (tendons-muscle to bone, ligaments-bone to bone, lower layer of skin/dermis) areolar - soft, pliable, “cobweb”, cushions and protects, soaks up fluid during inflammation, swelling/puffiness known as edema (widely distributed, holds organs together, underlies mucous membranes lamina propria) adipose (fat) - areolar tissues in which fat cells predominate (subcutaneous tissue, protects kidneys, eyeballs, hips, breasts) reticular - interwoven reticular fibers, support free blood cells (lymph nodes, spleen, bone marrow) blood - blood cells and plasma, transports nutrients, gases, and wastes (in blood vessels)

15. connective tissues (pictures pg 83-84)

16. muscle tissue Three types: skeletal - striated (stripes), multinucleated, voluntary movements (attached to skeletal bones) smooth - no striations, uninucleate, spindle- shaped, involuntary (walls of stomach, bladder, uterus, and blood vessels) cardiac - striated, uninucleate, branching cells, intercalated disks (gap junctions that conduct electrical impulse, involuntary (heart)

17. muscle tissue (picture pg 157)

18. nervous tissue neurons and supporting cells - cytoplasm drawn out into long extensions, electrochemical impulses (brain, spinal cord, nerves)

19. nervous tissue (picture pg 199)

20. tissue repair (wound healing) Two major ways: regeneration = replacement of destroyed tissue by same kind of cell fibrosis = repair by dense (fibrous) connective tissue, the formation of scar tissue; strong but lacks flexibility Which type used depends on type of tissue and severity. Clean cuts generally heal much more successfully than ragged tears of tissue. Epithelia and connective tissues regenerate well. Mature cardiac muscle and nervous tissue are amitotic and are repaired by fibrosis.

21. At the clinic Three patients in an intensive care unit are examined by the resident doctor. One patient has brain damage from a stroke, another had a heart attack that severely damaged his heart muscle, and the third has a severely damaged liver (a gland) from a crushing injury in a car accident. All three patients have stabilized and will survive, but only one will have full functional recovery through regeneration. Which one and why?