anatomy 3

  1. Tissues
    groups of similar cells and extracellular matrix/material that carry out a common function
  2. Four body tissues
    epithelium, connective tissue (CT), muscle, nerve
  3. Extracellular matrix
    fibers + interstitial fluid
  4. Characteristics of epithelia
    • nCovering or lining epithelia
    • ¨Skin, lining of digestive and respiratory tract, blood vessels, etc.
    • nGlandular epithelia
    • ¨Adenocarcinoma – cancer originating in glandular tissue
    • nColon cancer, breast cancer, pancreatic cancer, etc.
  5. Characteristics of covering/lining epithelia
    • nTissue is almost all cells with very little extracellular matrix
    • nPolarity: apical surface facing space, basal surface attached to body tissues at basement membrane
    • n
  6. Characteristics of epithelia
    • nBasement membrane: extracellular material located at the basal surface
    • nAvascular: no blood vessels
    • nInnervation: may have sensory nerve receptors within or nearby
    • nHigh regenerative capacity: mitosis carried out at basal layers
  7. Functions of epithelia
    • nPhysical protection against dehydration, abrasion, foreign substances (skin)
    • nSelective permeability: regulation of movement of material into and out of cells, i.e., into and out of body tissues (digestive system)
    • nSecretion: many epithelial cells synthesize and exocytose material, some cells form glands (salivary glands)
    • nSensations: sensory nerve endings in or near epithelia detect changes in the environment and relay the information to the CNS
  8. Classification of epithelia
    • nNumber of cell layers: simple = one layer,
    • stratified = >1 layer,
    • pseudostratified = one layer with cells of varying heights
    • nLook for
    • nuclei
  9. Classification of epithelia
    nCell shape: based on the shape of cells at the apical surface. Three shapes are found: squamous, cuboidal, and columnar.
  10. Types of epithelium
    • nSimple squamous epithelium
    • nSimple cuboidal epithelium
    • nSimple columnar epithelium
    • nStratified squamous epithelium
    • nPseudostratified columnar epithelium
    • nTransitional epithelium
  11. Simple squamous epithelium
    • nSingle layer of flat cells
    • ¨Flattened nucleus, little cytoplasm
    • ¨Delicate epithelium (little protection)
    • ¨Allows diffusion, osmosis, and/or filtration across epithelium
    • ¨Locations: alveoli in lungs, lining blood vessels (endothelium)
  12. Simple cuboidal epithelium
    • nSingle layer of cells with similar width and height
    • ¨Spherical nucleus
    • ¨Functions in transport and secretion (more organelles than simple squamous cells)
    • ¨Locations: kidney tubules, ducts of glands
  13. Simple columnar epithelium
    • nSingle layer of tall cells
    • ¨Oval nucleus at basal region
    • ¨Functions in secretion and absorption
    • ¨May contain cilia or microvilli
    • ¨Locations: digestive tract, uterine tubes
  14. Stratified squamous epithelium
    • nSeveral layers of cells
    • ¨Apical cells are flat
    • ¨Basal cells have varied shapes
    • ¨Serves to protect underlying tissues from abrasion and friction
    • ¨Basal cells undergo mitosis
    • ¨Oldest cells at superficial layer
  15. Pseudostratified columnar epithelium
    • nOne cell layer thick
    • nCells are of different heights with nuclei at different levels
    • nPseudostratified ciliated columnar (PSCC) with goblet cells
    • (respiratory tract)
  16. Transitional epithelium (urinary sys)
    • nStratified epithelium with variable shape
    • ¨Able to stretch
    • ¨Cells change from cuboidal to squamous
    • nLocation: urinary bladder and ureter
  17. Connective tissue structure
    • nComponents
    • ¨Cells
    • ¨Extracellular matrix
    • nFibers
    • nGround substance
    • nCT is mainly extracellular matrix, with scattered cells (vs. epithelium)
  18. Types of connective tissue
    • nConnective tissue proper – between organs; tendons and ligaments
    • nSupporting connective tissue – cartilage and bone
    • nFluid connective tissue - blood
  19. Connective tissue functions
    • nPhysical protection: skeletal system cavities, padding with fat
    • nSupport and structural framework: skeletal system, cartilage (e.g., trachea), capsules (e.g., liver)
    • nBinding of structures: ligaments, tendons, soft tissues between organs
    • nStorage: calcium and phosphate in bone, fat
    • nTransport: blood and blood cells
    • nImmune protection: white blood cells in connective tissues protect against infections
  20. Connective tissue proper components
    • nCells
    • nFibers
    • nGround substance
    • n
    • nContrast with epithelium
  21. Connective tissue proper cells
    • nFibroblasts – tapered at ends, elongated nuclei, produce fibers and fluid of ECF
    • nAdipocytes – contain fat droplet (inclusion body)
    • nFixed macrophages – phagocytize foreign material or cellular debris
    • nMesenchymal cells – CT stem cells
    • nLeukocytes (white blood cells)
  22. Connective tissue proper fibers
    • nCollagen fibers
    • ¨Made of protein collagen
    • ¨Strong, flexible, resist stretching
    • ¨Make up tendons and ligaments (e.g., anterior cruciate ligament)
    • ¨Other locations: dermis, organ capsules
    • ¨Usually stains pink with blue fibroblast nuclei
    • ¨
  23. Connective tissue proper fibers
    • nElastic fibers
    • ¨Made up protein elastin
    • ¨Stretches easily and returns to original length (elasticity)
    • ¨Branched fibers
    • ¨Located in skin, lungs, arteries
    • ¨Seen as internal elastic
    • membrane in medium
    • arteries.
  24. Connective tissue proper fibers nReticular fibers
    • ¨Made up of protein collagen
    • ¨Thin, branching fibers form a network
    • ¨Flexible and strong
    • ¨Forms a support like scaffolding
    • for spleen, liver, and lymph nodes
    • nLymphocytes and liver cells cling to
    • reticular fiber network
    • ¨Requires special staining
    • (black/blue)
    • ¨
  25. Connective tissue proper - types
    • nLoose connective tissue – scattered cells and fibers, between organs
    • ¨Areolar connective tissue
    • ¨Adipose connective tissue
    • ¨Reticular connective tissue
    • nDense connective tissue – mainly fibers
    • ¨Dense regular connective tissue
    • ¨Dense irregular connective tissue
    • ¨Elastic connective tissue
Card Set
anatomy 3