4. Wound Healing and Repair Flashcards
What is healing by first intention?
Occurs with clean wounds when there has been little tissue damage and the wound edges are closely approximated; surgical incision.
What is healing by secondary intention?
Occurs in wounds that have large tissue defects and when the two skin edges are not in contact; requires large amount of granulation tissue to fill in the defect.
What type of collagen is predominant in keloid formation?
Type III collagen.
Where do we see type I collagen?
Most common; high tensil strength; skin, bone, tendons, and most organs.
Where do we see type II collagen?
Cartilage and vitreous humor.
Where do we see type III collagen?
An immature for found in granulation tissue, keloid, embryonic tissue, uterus.
Where do we see type IV collagen?
Basement membranes.
What is required in the hydroxilation of collagen?
Vitamin C.
Who performs the cross-linking of collagen and what co-factor is necessary?
By lysyl oxidase; Copper is a required co-factor.
What causes scurcy and why are bleeding gums its first signs?
Vitamin C deficiency first affecting collagen with highest hydroxyproline content, such as that found in blood vessels. Thus, we see bleeding gums first.
What causes Ehlers Danlos syndrome?
Defect in collagen synthesis or structure. Some nine types. ED type IV is a defect in type III collagen.
What causes osteogenesis imperfecta?
Defect in collagen type I.
What causes Marfan syndrome?
Defect in fibrillin.
What are two adhesion molecules?
Fibronectin and Laminin.
What are two proteoglycans and glycosaminoglycans?
Heparan sulfate and chondroitin sulfate.
