A&P2 Cell Tissue


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A&P2 Cell Tissue

  1. 1. Cells & tissue<br />
  2. 2. Cells<br />1600’s: Robert Hooke<br />The Cell Theory<br />All living things are made up of cells<br />The cell is the basic unit of structure & function of all living things<br />All cells come from pre-existing cells<br />
  3. 3. Review of Cells<br />C, O, H, N<br />Interstitial fluid<br />Made from blood<br />All exchgsbt cells & blood made thru this fluid<br />Nucleus<br />Plasma membrane<br />Cytoplasm<br />
  4. 4. Review cont:<br />Cytosol<br />Mitochondrion<br />Ribosome<br />ER<br />Smooth<br />rough<br />Golgi apparatus<br />Lysosome<br />Secretory vesicles<br />Cytoskeleton<br />Centrioles<br />Cilia<br />flagella<br />
  5. 5. Cell Diversity<br />Cells that:<br />Connect body parts<br />Fibroblast<br />Elongated<br />Lies along the cable-like fibers that it secretes<br />Has lots of RER & GA to make & secrete protein bldg blocks of these fibers<br />Erthrocyte (RBC)<br />Carries O2<br />Concave disc=↑ SA<br />Streamlined = flows easily<br />So much O-carrying pigment is packed in that all other organelles have been removed to make room<br />
  6. 6. Cells that:<br />Covers & lines organs<br />Epithelial cells<br />Hexagonal<br />Pack together well<br />Many intermediat filaments wc resist tearing when rubbed/pulled<br />Move organs & body parts<br />Skeletal muscle & smooth muscle cells<br />Elongated<br />Filled w/ contractile filaments<br />Shorten<br />Move bones<br />Change size of organs<br />
  7. 7. Cells that:<br />Store nutrients<br />Fat cells<br />Large & round<br />From lg lipid droplet in cytoplasm<br />Fight disease<br />Macrophage (phagocytic cell)<br />Long pseudopods sent out to infection<br />Has many lysosomeswc digest infectious microorgs<br />
  8. 8. Cells that:<br />Gather info & controls body functions<br />Nerve cell<br />Very long<br />Receives & transmits to other parts of body<br />Covered w/ lg plasma membr<br />Many rER to make parts of membr<br />Are for reproduction<br />Oocyte (f)<br />Lgst cell<br />Has many copies of all organells to distribute to daughter cells<br />Sperm (m)<br />Long, streamlined for “swimming”<br />Flagellum to propel<br />
  9. 9. Body Tissues<br />Epithelial Tissue (epithelium)<br />lining, covering & glandular tissue<br />Glandular epithelium forms glands<br />Lining & covering epith covers all free body surfaces<br />Contains versatile cells<br />intestine<br />
  10. 10. Can form outer layer of skin<br />Almost all subs that body give/receives must go thru epith<br />Can dip in to line cavities<br />Functions:<br />Protection<br />Absoption<br />Filtration<br />Secretion<br />kidney<br />
  11. 11. Special Characteristics<br />Fit close together, forming sheets<br />Bound together at many pts by cell junctions (desmosomes & tight junctions)<br />Has an apical surface (unattached)<br />Slick, smooth, microvilli, cilia<br />Has a basement membr (lower surface)<br />Secreted by both epithel cells & connective tissue cells next to it<br />Avascular (lack own blood supply)<br />Depends on diffusion from capillaries for nutrients & O2<br />Easily self regenerates<br />
  12. 12. Classification of Epithelium<br />2 names<br />First: = number of cell layers it has<br />Simple epith= one layer<br />Stratified epith=more than one cell layer<br />Second = describe the shape of its cells<br />Squamous = flat<br />Cuboidal = cube<br />Columnar = columns<br />Stratified epith named for apical surface<br />
  13. 13. Simple Epithelia<br />Thin layer<br />≠ protection<br />=absorption, secretion, filtration<br />Simple Squamous<br />Rests on basement layer<br />Air sacs<br />Walls of capillaries<br />Simple Cuboidal<br />Rests on basement layer<br />In glands and ducts<br />Salivary glands, pancreas, walls of kidney tubules, surface of ovaries<br />Simple Columnar<br />Tall<br />Goblet cells<br />Product lubricating mucus<br />Entire length of digestive tract (stomach to anus)<br />Line body cavities open to body exterior = mucosae/mucus membranes<br />
  14. 14. Pseudostratified columnar<br />Rests on basement membr<br />BUT: some cells shorter than others<br />Nuclei at diff heights<br />False impression that it is stratified<br />Absorption/secretion<br />Ciliated variety = lines resp tract<br />Goblet cells traps dust/debris<br />
  15. 15. Stratified Epithelia<br />More durable<br />= protection<br />Stratified Squamous<br />Most common stratepith<br />Apical = squamous<br />Basement memb = cub or col<br />Subject to abuse/friction<br />Esophagus, mouth, outer skin<br />
  16. 16. Stratified Cuboidal<br />Usually just 2 layers<br />At least apical cells cub<br />Stratified Columnar<br />Apical cells col<br />Basal cells vary in size & shape<br />Both fairly rare<br />Mainly in ducts of lg glands<br />
  17. 17. Transitional Epithelium<br />Highly modified stratified squamousepith<br />Forms lining of only few organs<br />Urinary bladder, ureters & parts of urethra<br />Subject to considerable stretching<br />Basal layer cub or col<br />Apical cells vary<br />Not Stretched = membr many layered, surface cells rounded/domed<br />Stretched = (w/urine) epith thins, surface cells flatten & become squamous-like<br />Allows cells to slip past ea other & chg shape (=transition)<br />
  18. 18. Glandular Epithelium<br />Gland=make & secrete a specific product = secretion<br />2 Major Types of Glands<br />Endocrine glands<br />Lose connection to surface (duct) = ductless<br />All hormones<br />Secretions diffuse directly into blood vessels<br />Thyroid, adrenals & pituitary<br />
  19. 19. Exocrine Glands<br />Have ducts where secretion occurs to surface<br />Sweat & oil glands, liver & pancreas<br />Both internal & external<br />
  20. 20. Connective Tissue<br />Connects body parts<br />Everywhere, most abundant & distributed tissue<br />Protecting, supporting & binding together other body tissues<br />
  21. 21. Characteristics<br />Variations in blood supply<br />Most well vascularized<br />Tendons & ligaments = poor blood supply<br />Cartilages = avascular<br />= slow to heal<br />Would you rather break a bone or tear a ligament?<br />
  22. 22. Extracellular Matrix<br />made of many diff types of cells & varying amts of nonliving substance outside the cells = extracellular matrix<br />
  23. 23. Extracellular Matrix<br />Made by CT then secreted to outside<br />2 main elements<br />Structureless ground substance<br />fibers<br />Ground substance = mostly water plus adhesion proteins (“glue”) and lg charged polysaccharide molecule (will trap water as they intertwine)<br />Matrix can be very fluid, gel-like, firm, rock hard<br />
  24. 24. Fibers = various types & amts<br />Include: <br />collagen = white, hi tensile strength<br />Elastic = yellow<br />Reticular = fine collagen fibers wc form internal “skeleton” of soft organs (spleen)<br />
  25. 25. Due to the extracellular matrix, connective tissue is able to<br /> form soft packaging tissue around organs<br />bear weight<br />w/stand stretching<br />w/stand abuse/abrasion w/c other tissues couldn’t<br />
  26. 26. Variations of connective tissue<br />One extreme to another<br />Fat tissue = many cells, matrix is soft<br />Bone & cartilage = few cells, very hard matrix (strong)<br />
  27. 27. Types of Connective Tissue<br />Bone (osseous)<br />= bone cells in lacunae (pits)<br />surrounded by very hard matrix<br />matrix contains Ca salts & lg amts of collagen fibers<br />Excellent protection & support<br />
  28. 28. Cartilage<br />=less hard, more flexible<br />only in a few places<br />most common = hyaline cartilage (glassy)<br />Many collagen fibers in rubbery matrix<br />Forms supporting structures<br />Larynx<br />Ribs to breastbone<br />Ends of bones at joints<br />Fetus = mostly hyaline, replaced by bone by birth<br />Fibrocartilage<br />Highly compressible<br />Disks bt vertebrae<br />Elastic cartilage<br />ear<br />
  29. 29. Dense Connective Tissue<br />Main matrix element = collagen fibers (in rows w/fibroblasts)<br />Forms strong rope-like structures<br />Tendons (m2b)<br />Ligaments (b2b)<br />More elastic/stretchy<br />Lower layer of skin (dermis) = in sheets<br />
  30. 30. Loose CT<br />Softer<br />More cells, fewer fibers (except blood)<br />Areolar tissue<br />Soft/cobwebby<br />Cushions/protects organs <br />‘glue’ wc holds organs in their positions<br />Fluid matrix w/all types of fibers<br />Appears to be empty space<br />A resevoir of water & salts for all other cells to get nutrients and dispose of “wastes”<br />Adipose tissue<br />Reticular CT<br />
  31. 31. Adipose tissue<br />Fat<br />Mostly oil… pushes nucleus to one side<br />Beneath skin<br />Insulates/protects<br />Kidneys surrounded<br />Cushions eye in socket<br />For fuel if needed<br />Reticular CT<br />Interwoven reticular fibers<br />Limited sites: stroma to support free blood cells in lymph nodes, spleen, bone marrow<br />
  32. 32. Loose connective tissue types<br />Reticular connective tissue<br />Delicate network of interwoven fibers<br />Forms stroma (internal supporting network) of lymphoid organs<br />Lymph nodes<br />Spleen<br />Bone marrow<br />
  33. 33. Blood (vascular tissue)<br />Blood cells surrounded by fluid matrix called blood plasma<br />Fibers are visible during clotting<br />Functions as the transport vehicle for materials<br />
  34. 34. Muscle Tissue<br />Function is to produce movement<br />Three types<br />Skeletal muscle<br />Cardiac muscle<br />Smooth muscle<br />
  35. 35. Muscle Tissue Types<br />Skeletal muscle<br />Under voluntary control<br />Contracts to pull on bones or skin<br />Produces gross body movements or facial expressions<br />Characteristics of skeletal muscle cells<br />Striated<br />Multinucleate (more than one nucleus)<br />Long, cylindrical<br />
  36. 36. Cardiac muscle<br />Under involuntary control<br />Found only in the heart<br />Function is to pump blood<br />Characteristics of cardiac muscle cells<br />Cells are attached to other cardiac muscle cells at intercalated disks<br />Striated<br />One nucleus per cell<br />
  37. 37. Smooth muscle<br />Under involuntary muscle<br />Found in walls of hollow organs such as stomach, uterus, and blood vessels<br />Characteristics of smooth muscle cells<br />No visible striations<br />One nucleus per cell<br />Spindle-shaped cells<br />
  38. 38. Nervous Tissue<br />Composed of neurons and nerve support cells<br />Function is to send impulses to other areas of the body<br />Irritability<br />Conductivity<br />
  39. 39. Tissue Repair (Wound Healing)<br />Regeneration<br />Replacement of destroyed tissue by the same kind of cells<br />Fibrosis<br />Repair by dense (fibrous) connective tissue (scar tissue)<br />Determination of method<br />Type of tissue damaged<br />Severity of the injury<br />
  40. 40. Events in Tissue Repair<br />Capillaries become very permeable<br />Introduce clotting proteins<br />A clot walls off the injured area<br />Formation of granulation tissue<br />Growth of new capillaries<br />Rebuild collagen fibers<br />Regeneration of surface epithelium<br />Scab detaches<br />
  41. 41. Regeneration of Tissues<br />Tissues that regenerate easily<br />Epithelial tissue (skin and mucous membranes)<br />Fibrous connective tissues and bone<br />Tissues that regenerate poorly<br />Skeletal muscle<br />Tissues that are replaced largely with scar tissue<br />Cardiac muscle<br />Nervous tissue within the brain and spinal cord<br />
  42. 42. Developmental Aspects of Tissue<br />Epithelial tissue arises from all three primary germ layers<br />Muscle and connective tissue arise from the mesoderm<br />Nervous tissue arises from the ectoderm<br />With old age, there is a decrease in mass and viability in most tissues<br />