Question

Label the parts A,B,C, D,E and give a proper title to the diagram.

Answer 1

In response to a stimulus, a reflex, or reflex movement, is an automatic and almost spontaneous motion. A reflex is made possible by neural mechanisms called reflex arcs that may act on an impulse before the brain hits that impulse. The reflex is therefore an unconscious reaction to a stimulus that does not undergo conscious thinking or requires it.

Complete answer:
A cortical pathway that controls a reflex is a reflex arc. Many sensory neurons do not move immediately through the brain of vertebrates, but synapse across the spinal cord. This encourages quicker reflex acts to occur without the interruption of routing impulses through the brain by triggering spinal motor neurons.
A- receptor
B-sensory neuron
C- Association neuron
D-Motor neuron
E- effector

If only one sensory neuron and one motor neuron consist of a reflex arc in an animal, it is known as monosynaptic, referring to the involvement of a single chemical synapse. In the case of peripheral muscle reflexes (patellar reflex), fast muscle spindle stimulation results in the relaxation of the muscle of the agonist or effector. In comparison, one or more interneurons connect afferent (sensory) and efferent (motor) signals in polysynaptic reflex pathways.

Note: When touching the patellar tendon just below the knee, is a specialized system known as a muscle spindle situated inside the quadriceps, the tap initiates an action potential. The ability for this action passes via a sensory axon to the L3 and L4 nerve roots of the spinal cord, which chemically interacts by releasing glutamate to the motor nerve. Contraction of the quadriceps muscle is the result of this motor nerve operation, resulting in an extension of the lower leg at the knee.