Test on Skin Grafting: Principles and Practice

Question 1: Pre- and postauricular regions are listed as full-thickness donor sites in the head and neck.

A. Ano

B. Ne

Explanation: The study materials explicitly state that full-thickness donor sites in the head and neck include pre- and postauricular regions.

Question 2: According to the study materials, what are the functions of topical gauze soaked in diluted epinephrine solution when applied to a skin graft donor site?

A. To promote rapid re-epithelialization of the wound.

B. To stop bleeding and provide an analgesic effect.

C. To facilitate the primary closure of large donor sites.

D. To prevent serum accumulation under semiocclusive dressings.

Explanation: The study materials state that "Topical gauze soaked with diluted epinephrine solution is useful to stop bleeding at the donor site and can be left until the operation is ended, adding an analgesic effect."

Question 3: Is the differentiation of fibroblasts into myofibroblasts, which induces wound contraction, primarily caused by the direct presence of fibrin in the wound bed?

A. Ano

B. Ne

Explanation: The study materials state that the development of alpha-SMA fibers by fibroblasts, coinciding with their differentiation into myofibroblasts, occurs due to the increased mechanical resistance from collagen deposition and cross-linking. Fibrin is noted as being crucial for early cell migration, not for directly causing the differentiation into myofibroblasts that induce wound contraction.

Question 4: According to the study materials, what technique can be employed to reduce bleeding specifically during the excision phase of skin grafting?

A. Injecting epinephrine diluted in saline into the area

B. Applying topical thrombin to control oozing

C. Performing suture ligation on all vessels after excision

D. Using a compressive dressing to facilitate fluid evacuation

Explanation: The study materials state: "To reduce bleeding during excision the area can be primarily injected with epinephrine diluted in saline (tumescent technique...)." The other options describe methods for controlling bleeding after it has occurred or managing fluids after grafting, not specifically for reducing bleeding during excision.

Question 5: Matriderm, a synthetically engineered dermal substitute, is characterized by its collagen matrix containing cross-linked collagen fibers.

A. Ano

B. Ne

Explanation: The study materials describe Matriderm as a bovine-derived collagen matrix with noncross-linked collagen fibers of types I, III, and V, coated with elastin fibers. It does not contain cross-linked collagen fibers.