- Stimulation of vagosympathetic trunk results in cardiac inhibition.
- If the stimulation continues, the heart recovers from the inhibitory effect of the vagus.
Q1. What is vagal escape? What are the causes of vagal escape?
A strong vagal stimulation stops heart automatically.
However the heart recovers and starts beating automatically and the phenomenon
is known as vagal escape
Causes:
- Idioventricular rhythm – significantly lower than the normal heart rate
- Depletion of acetylcholine – depletion of acetylcholine by enzyme cholinesterase
- Sympathetic stimulation – when vagosympathetic trunk is continuously stimulated, the sympathetic fibers are also activated which stimulate the heart.
Q2. What is White Crescentic Line?
The White Crescentic Line is the parasympathetic ganglion
(Remak’s ganglion) in the frog’s heart and its stimulation causes cardiac
inhibition.