Involuntary Action: These actions occur without the thinking of a person or his conscious.
The brain controls it.
Example: Churning of stomach, heartbeat.
Reflex action: Spontaneous action for any stimulus.
It is controlled by the spinal cord.
Example: knee-jerk when the hammer strikes knee.
Signals in a synapse from the axonal end of one neuron to dendritic end of another neuron but not the reverse is because of the chemicals/ neurotransmitter released at the axonal end where electric signals get converted to chemical signals. These neurotransmitters from axonal end move towards dendrites of another neuron, and hence, the signal gets transmitted.
Rate this question :