A&P_Lab[1] classification of tissues.txt

  1. Tissues
    Groups of cells that are similar in structure and function
  2. Organs
  3. organs
    A part of the body formed of two or more tissues and adapted to carry out a specfic function
  4. histology
    the study of tissues
  5. epithelial tissue (epithelium)
    covers surfaces; covers external body surface, lines it cavities and tubules, and generally marks off our insides from our outsides.
  6. characteristics of epithelial tissues
    • polarity- membranes always have one free surface (apical surface), typically significally differenct from basal surface.
    • cellularity and specialized contacts- cells fit closely together
    • supported by connective tissues- adhesive basement membrane (basal lamina) connective tissue (reticular lamina)
    • avascularity- no blood supply of their own, diffusion of nutrients from the underlying connective tissue
    • regeneration-if well nurished, cells can reginerate themselves
  7. 2 criteria of epithelia
    • simple-one layer of cells attached to the basement membrane
    • stratified-2 or more layers of cells
  8. types of epithelial tissues
    • squamous (scalelike)
    • cuboidal (cubelike)
    • columnar (column-shaped)
  9. pseudostratified epithelium
    cells vary in height and the nuclei lie at different levels above the basement membrane, gives the false appearance of being stratified
  10. Transitional epithelium
    stratified squamous epithelium of rounded or plump cells with the ability to slide over one another to allow the organ to be stretched-found in urinary systme subjected to periodic distention (bladder).
  11. endocrine glands
    ductless glands, secrete hormones
  12. exocrine glands
    retain their ducts, secretions empty through ducts, internal and external ...sweat and oil glands, liver, pancreas
  13. simple squamous epithelium
    • single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm- simplest of the epithelia
    • function- allows passage of materials by diffusion and filtration in sites where protection is not important; secretes lubricating substances in serosae
    • found in kidney glomeruli, air sacs of lungs, lining of heart, blood vessels, lymphatic vessels, lining of ventral body cavity (serosae)
    • Cells touching cells-no space between cells
  14. simple cuboidal epithelium
    • single layer of cubelike cells with large spherical central nuclei
    • function-secretion and absorption
    • location-kidney tubules, ducts and secretory portions of small glands, ovary surface
  15. simple columnar epithelium
    • single layer of tall cells with round to oval nuclei, some cells bear cilia, layer may contain mucus-secreting unicellular glands (goblet cells)
    • function-absorption and secretion of mucus, enzymes and other substances;ciliated type propels muicus by ciliary action
    • location- nonciliated type lines most of the digestive tract (stomach to anal canal), gallbladder, and excretory ducts of some glands; ciliated variety lines small bronchi, uterine tubes and some regions of the uterus
    • Goblet cells have mucus in them
  16. stratified squamous epithelium
    • thick membrane composed of several cell layers-
    • function-protects underlying tissues in areas subjected to abrasion
    • location-nonkeratinized type forms the moist linings of the esophagus, mouth and vagina; keratinized variety forms the epidermis of the skin, a dry membrane
  17. connective tissue
    found in all parts of the body as discrete structures or as part of various body organs, the most abundant and widely distributed of the tissue types. functions- protect, support and bind together other tissues
  18. bone (osseous tissue)
    protect and support other body tissues and organs
  19. dense connective tissue
    ligaments and tendons- bind the bones together or bind skeletal muscles to bones
  20. areolar connective tissue
    soft packaging material that cushions and protects body organs
  21. adipose
    fat tissue provides insulation for the body tissues and a source of stored food
  22. hematopoietic tissue
    blood forming tissue replenishes the body's supply of red blood cells
  23. characteristics of connective tissue
    • rich supply of blood vessesl (with some exceptions)
    • composed of many types of cells
    • great deal of noncellular, nonliving material (matirx) between the cells of connective tissue
  24. extracellular matrix
    nonliving material between the cells- distinguishes connective tissue from all other tissues-primarily responsible for strength associated with connective tissue
  25. ground substance
    • component of matrix- composed chiefly of interstitial fluid, cell adhesion proteins and proteoglycans; liquid, semisolid, gel-like or very hard (glue)
    • the fibers which provide support, include collagen (white), elastic (yellow), and reticular (fine collagen) - collagen fibers are most abundant
  26. connective tissue proper: loose connective tissue, areolar
    • gel-like matrix witha ll three fiber types; cells:fibroblasts, macrophages, mast cells, and some white blood cells
    • function- wraps and cushions organs, plays important role in inflammation, holds and conveys tissue fluid
    • location-widely distributed under epithelia of body; forms lamina propria of mucous membranes, packages organs, surrounds capillaries
  27. connective tissue proper: loose connective tissue, adipose
    • matrix as in areolar, but very sparse; closely packed adipocytes (fat) nucleus pushed to the sideby large fat droplet
    • function- provides reserve fuel, insulates against heat loss, supports and protects organs
    • locatations-under skin, around kidneys and eyeballs, within abdomen, in breasts
  28. connective tissue proper: dense connective tissue, dense regular
    • primarily parallel collagen fibers, a few elastin fibers; major cell type is the fibroblast
    • function- attaches muscles to bones or to muscles, attaches bones to bones, withstands great tensile stress when pulling force is applied in one direction
    • locatation-tendons, most ligaments, aponeuroses
  29. connective tissue proper:dense connective tissue, dense irregular
    • primarily irregularly arranged collagen biers, some elastic fibers, major cell type is the fibroblast
    • function-able to withstand tension exerted in many directions, provides structural strength
    • location-dermis of the skin, submucosa of digestive tract, fibrous capsules of organs and joints
  30. cartilage: hyaline
    • amorphous but firm matrix; collagen fibers form an imperceptible network; chrondroblsts produce the matrix and when mature lie in lacunae
    • function-support and reinforces has resilient cushioning properties, resists compressive stress
    • location-forms most of the embryonic skeleton, covers the ends of long bones in joint cavities, forms costal cartilages of the ribs; cartilages of the nose, trachea and larynx
  31. cartilage:elastic
    • similar to hyaline cartilage, but more elsastic fibers in matrix
    • function-maintains the shape of a structure while allowing great flexibility
    • location-supports the external ear, epiglottis
  32. cartilage: fibrocartilage
    • matrix similar to but less firm than that in hyaline cartilage, thick collagen fibers predominate
    • function-tensile stenght with the ability to absorb compressive shock
    • location-intervertebral discs, pubic symphysis, discs of knee joint
  33. mast cells
    large, darkly staining granules in its cytoplasm
  34. nervous tissue
    • 2 major cell populations-
    • neuroglia-special supporting cells that protect support and insulate themore delicate neurons
    • neurons- highly specialized to receive stimuli, and to conduct waves of excitation, or impulses to all parts fot the body
  35. muscle tissue
    highly specialized to contract and produce most types of body movement
  36. skeletal muscle
    the meat or flesh, attached to the skeleton
  37. cardiac muscle
    found only in the heart, involuntary muscle control
  38. smooth muscle
    also called visceral muscle, found mainly in the walls of hollow organs- no striations are visible the uninucleate smooth muscle cells are spindle shaped
Card Set
A&P_Lab[1] classification of tissues.txt
classification of tissues