BIOL 2130 Lecture Notes - Lecture 14: Neoplasm, Genetic Programming, Hyperplasia
Document Summary
Inflammation: capillaries become very permeable, clotting proteins migrate into the area from the bloodstream, a clot walls off the injured area. Granulation tissue forms: growth of new capillaries, phagocytes dispose of blood clot and fibroblasts, rebuild collagen fibers. Regeneration of surface epithelium: scab detaches, whether scar is visible or invisible depends on severity of wound. Tissues that regenerate easily: epithelial tissue (skin and mucous membranes, fibrous connective tissues and bone. Tissues that are replaced largely with scar tissue: cardiac muscle, nervous tissue within the brain and spinal cord. Growth through cell division continues through puberty. Cell populations exposed to friction (such as epithelium) replace lost cells throughout life. Connective tissue remains mitotic and forms repair (scar) tissue. With some expectations, muscle tissue becomes a-mitotic by the end of puberty. Nervous tissue becomes a-mitotic shortly after birth. The cause of aging is unknown, but chemical and physical insults, as well as genetic programming, have been proposed as possible causes.
