Muscle Physiology

Question 1

What is Raynaud’s phenomenon caused by?

Answer 1

Skin discoloration due to abnormal spasm of vascular smooth muscle in peripheral tissues -> a diminished blood supply to local tissues

Skin discoloration upon temperature or emotional changes: initially, digit(s) involved turn white due to diminished blood supply. The digit(s) then turn blue because of prolonged lack of oxygen. Finally, the blood vessels reopen, causing a local “flushing” phenomenon, which turns the digit(s) red