This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Physiology
Activation of which receptor causes pulmonary vasoconstriction? 
Select and explain. 
A. Alpha 2 adrenergic, B. H2 histamine, C. M3 cholinergic, D. ETA epithelial receptor
D: ETA epithelial receptor
Answer: D: ETA epithelial receptor 
Explanation: Activation of ETA receptor causes pulmonary vasoconstriction. These are endothelin receptors.Ref: Ganong review of medical physiology, 23rd edition Page no: 609