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
All are effects of sympathetic stimulation, EXCEPT: 
Select and explain. 
A. Increased conduction velocity, B. Increased hea rate, C. Increased refractory period, D. Increased contractility of hea
C: Increased refractory period
Answer: C: Increased refractory period 
Explanation: C i.e. Increased refractory periodEffect of sympathetic system on hea mediated by Pi and (ix receptorsSA nodeIncrease in hea rateA.V. nodeIncrease in conduction velocityHis- Purkinje systemIncrease in conduction velocityAtriaIncrease in contractility & conduction velocityVentriclesIncrease in contractility