This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
Sympathetic system has adrenergic nerve endings at all sites except? 
Select and explain. 
A. Hea, B. Blood vessels in skeletal muscles, C. Eye, D. None
B: Blood vessels in skeletal muscles
Answer: B: Blood vessels in skeletal muscles 
Explanation: Ans. is 'b' i.e., Blood vessels in skeletal muscles(Ref: Principles of medical physiologY p. 241Sympathetic adrenergic fibers are those which secrete endogenous catecholamines (either adrenaline, nor-epinephrine / nor-adrenaline or dopamine)Some sympathetic fibers do not secrete catecholamines but secrete acetylcholine -Sweat glandsBlood vessels in skeletal muscles