Irregular and unpredictable vasoconstriction in the fingertips and toes (such as occurs in Raynaud's syndrome)would most likely be caused by
A)insufficient vasomotor responses by the sympathetic nervous system.
B)irregular and unpredictable responses by the parasympathetic division.
C)both local and systemic defects in sympathetic response controlling muscle tone in vessel walls.
D)defective control of blood pressure by both the sympathetic and parasympathetic divisions.
E)None of the answers are correct.

Question

Quizplus · Accepted Answer

Irregular and unpredictable vasoconstriction in the fingertips and toes in Raynaud's syndrome is caused by both local and systemic defects in sympathetic response controlling muscle tone in vessel walls. This results in exaggerated vasoconstriction of arterioles in response to cold or emotional stress, leading to reduced blood flow to the affected areas. The parasympathetic division is not involved in this process, and there is no evidence of insufficient vasomotor responses by the sympathetic nervous system or defective control of blood pressure by both the sympathetic and parasympathetic divisions.

Irregular and Unpredictable Vasoconstriction in the Fingertips and Toes (Such