Spasm of digital vessels in the hands in response to cold (Raynaud’s phenomenon) may be relieved by

A. True Sympathetic nerves to digital vessels are tonic vasoconstrictor nerves.

B. False The hand does not have a parasympathetic nerve supply.

C. True Alpha receptors mediate sympathetic vasoconstriction.

D. False Digital vessels have few beta receptors.

E. False Raynaud’s phenomenon is triggered by cold and wearing gloves may prevent cooling to the threshold temperature.