Question

Draw a well labelled diagram of reflex arc and explain reflex action.

Answer 1

Hint:The involuntary and sudden or instantaneous movement made by neural pathways in response to a stimulus is called a reflex arc.

Complete answer:

Reflex arcs are initiated by the excitation or stimulation of sensory cells that are connected to the motor neuron. Some reflex arcs also include coordination between the spinal cord or brain earlier to the stimulation of the motor nerve. Generally, a basic reflex arc includes different segments namely sensory cells and their associated nerve fibers, motor nerve fibers and muscle or gland that show action. The sensory aspects of reflex arcs categorize or different reflex arcs into two different types namely: autonomic reflexes and somatic reflexes.
(a) Autonomic reflexes: The reflexes have ability to stimulate as well as inhibit smooth muscle gland. They regulate smooth muscle cells, cardiac muscle cells and numerous glands.
(b) Somatic reflexes: These reflexes involve control of reflex muscles and have various different reflexes such as tendon reflex and withdrawal reflex.

Note:Some reflex actions are conditional whereas some are unconditional. Example: Discharge of saliva while thinking about food and during eating are different conditions.