Question

Acetylcholine reacting with a muscainic receptor on a cardiac myocyte causes chloride to flow, or an :

A. action potential

B. IPSP

C. ESPS

D. None of the above

Answer 1

Ans:- B). IPSP

Parasympathetic nervous system release acetylcholine , then this acetylcholine bond to M2 muscarinic receptor and cause following change to decreaease heart rate:-

1) increase influx of Cl- and generate a inhibitory post synaptic potential. By hyperpolarising the neuron. Because influx of Cl- inside cell cause negative environment inside the cell.

2) increase K EFFLUX

3) DECREAEASE cAMP WHICH SLOW OOENING OF Ca channel .

Other options are wrong because EPSP AND ACTION POTENTIAL IS NOT GENERATED WHEN THERE IS CHLORINE INFLUX. IT OCCURE WHEN THERE IS Na influx.