Question

A reflex arc in man is best described as movement of stimuli from:

• A. Receptor cell, sensory neuron, relaying neuron, effector muscles.
• B. Receptor cell, efferent nerve, relaying neuron, muscles of the body.
• C. Receptor cell, spinal cord, motor neuron, relaying neuron.
• D. Receptor cell, synapse, motor neuron, relaying neuron.

Answer 1

The correct option is A

Receptor cell, sensory neuron, relaying neuron, effector muscles.

The correct option is A.

The explanation for the correct option:

1. Reflex arc: The path through which reflex action takes place and extends between sensory organ to effector organ through grey matter of the spinal cord is called the reflex arc.
2. Receptor: To accomplish a reflex action, the reflex arc must be directly linked with a receptor organ. Reflex action occurs when sense organs or receptors are excited by a stimulus.
3. Sensory neurons: These neurons of a reflex arc remain connected with the receptor. they carry impulses from the receptor to the grey matter of the spinal cord.
4. Spinal cord(grey matter of the spinal cord): Grey matter of the spinal cord act as the center of reflex action. In the grey matter of the spinal cord, sensory impulses are analyzed and interpreted.
5. Motor neurons: Motor neurons carry the information from the spinal cord to the effector organ.
6. Effector organ: Effector organs are capable of responding to a stimulus to perform a particular action. Generally, muscles, glands, etc., participate as effector organs.
7. The reflex arc is constituted of five parts that are−

Receptor ⇒ Sensory neuron ⇒ spinal cord ⇒ Motor neuron ⇒ Effector organ

Final answer: Hence, according to the question of the reflex arc will be:

Receptor ⇒ Sensory neuron ⇒ Relaying neuron(spinal cord) ⇒ Effector muscle