iii. Contact inhibition: cells stop moving when they contact each other
B. Deep wound healing: extensive damage to epidermis, dermis and subcutaneous layer; involves scar tissue formation and loss of function
Ex. Deep cuts, 2 nd and 3 rd degree burns
i. Inflammation: blood clot forms in the wound and loosely joins wound edges. White blood cells arrive through the blood stream to perform immune responses and fibroblasts initiate repair. ii. Migration: blood clot becomes a scab and epithelial cells migrate below the surface to close off the wound
Granulation tissue fills the wound, composed of collagen, glycoproteins and blood vessels.
iii. Proliferation: growth of epithelial cells under the scab and continued deposition of collagen and blood vessel growth in the wound iv. Maturation: scab is released from the wound when the epidermis regains normal thickness, collagen becomes organized into bundles, blood vessels are fully developed, and fibroblast numbers decrease
Fibrosis: the process of scar tissue formation.
Hypertrophic scar: one that is elevated above the normal epidermal surface but remains within the boundaries of the wound. Atrophic scar: one that is depressed below the epidermal surface often due to the loss of underlying structures, such as muscle or fat.
Keloid scar: AKA Cheloid Scar
If the scar extends beyond the boundaries into normal surrounding tissue, it is called a Keloid Scar.
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