Describe the events of reflex action with a diagrammatic representation of knee jerk reflex.

Explanation

The reflex action pathway comprises of following events.
The stimulus is received by a receptor (eg. Muscle spindle). Afferent neuron receives signals from this sensory organ and transmits the impulse via a dorsal nerve root into the CNS (at the level of spinal cord). The efferent neutron then carries the signals from CNS to the effectors.
The strimulues and response thus forms a reflex arc.