Tissue Repair Flashcards
What are the 3 ECM components?
collagens and elastins
gels (proteoglycans and hyaluronan)
glycoproteins and cell adhesion molecules
What are labile cells primarily composed of?
primary stem cells
What are examples of labile cells in the body?
surface epithelial cells (skin and mucosal lining), hematopoietic cells, etc
Examples of locations where stable cells are found in the body?
hepatocytes, proximal tubule cells, endothelium, etc
Examples of permanent cell locations in the body?
neurons and cardiac muscle
What is primary wound healing?
Also called healing by first intention
occurs when wounds are closed physically with sutures, metal staples, dermal adhesive
What is secondary union?
Healing by secondary intention
occurs when wounds are allowed to heal by wound contraction and is mediated by myofibroblasts at the edge of the wound
Describe wound healing of the liver.
mild injury is repaired by regeneration of hepatocytes sometimes with restoration to normal pathology
severe or persistent injury > regenerative nodules that may be surrounded by fibrosis > hepatic cirrhosis
Wound healing of the brain steps.
neurons do no regenerate, but microglia remove debris and astrocytes proliferate, causing gliosis
Describe wound healing of the heart muscle.
Heart muscle cannot regenerate so heart heals by fibrosis
Describe wound healing of the lungs.
Type II pneumocytes replace type I pneumocytes after injury
Describe wound healing of peripheral nerves.
distal part of axon degenerates while proximal part regrows slowly using axonal sprouts to follow Schwann cells to the muscle
What is a hypertrophic scar?
prominent scar that is localized to the wound, due to excess production of granulation tissue and collagen. (common in burn patients)
