Which statement BEST describes Raynaud's phenomenon?

• A. Condition in which cold exposure causes vasospasm in the major veins of the hands.
• B. Condition in which cold exposure causes vasospasm of the digital arteries.
• C. Condition in which cold exposure causes vasodilation of the digital arteries.
• D. Condition in which heat exposure causes vasodilation in the major veins of the hands.

Answer: (B)

Raynaud's phenomenon involves episodic constriction of the small arteries supplying the fingers (the digital arteries) in response to cold or stress, leading to transient ischemia of the digits. Cold exposure triggers smooth muscle vasospasm, reducing blood flow and causing color changes (often white then blue) followed by redness when circulation returns. This is an arterial issue affecting the digits, not the major veins, and it involves vasoconstriction rather than vasodilation. The statement that best describes it is the one indicating vasospasm of the digital arteries with cold exposure.