NEET BIOLOGY

Detailed explanation-1: -The correct answer is Receptor → Spinal cord → Muscle. In the reflex action, the reflex arch is formed by Receptor → Spinal cord → Muscle. A reflex arc is a neural pathway that controls a reflex action.

Detailed explanation-2: -In reflex actions, a reflex arc is formed by impulses from the receptor reaching the spinal cord and the appropriate reflex impulse then being sent to the muscles by the spinal cord. The impulse is not sent to the brain, to reduce response time.

Detailed explanation-3: -Spinal cord reflexes are simple behaviors produced by central nervous system (CNS) pathways that lie entirely within the spinal cord. The sensory afferent fibers that evoke these reflexes enter the spinal cord and activate spinal motor neurons directly or through a chain of one or more spinal interneurons.

Detailed explanation-4: -A sensory nerve enters the spinal cord by a dorsal root or its cranial equivalent. The cell body of the spinal sensory afferent is in the dorsal root ganglion (the cranial equivalent is the nucleus of the cranial nerve). This is the afferent limb of the reflex arc.

Detailed explanation-5: -The primary components of the reflex arc are the sensory neurons (or receptors) that receive stimulation and in turn connect to other nerve cells that activate muscle cells (or effectors), which perform the reflex action.