Question

What is the correct sequence of the components of a reflex arc?

• A. receptors----muscles----sensory neuron----motor neuron----spinal cord
• B. receptor----motor neuron----spinal cord----sensory neuron----muscle
• C. receptor----spinal cord----sensory neuron----motor neuron----muscle
• D. receptor----sensory neuron----spinal cord----motor neuron----muscle

Answer 1

The correct option is D

receptor----sensory neuron----spinal cord----motor neuron----muscle

The correct option is D.

Explanation of the correct option:

1. Reflex arc is the sensory mechanism that controls a reflex action.
2. Automatic response to the action of a stimulus is called reflex action.
3. The sensory cells carry the input from the receptor impulses to a central interneuron, which makes contact with a motor neuron to produce a reflex.
4. The order of correct sequence of reflex action includes: receptor----sensory neuron----spinal cord----motor neuron----muscle.

Explanation of the incorrect options:

Option A:

Reflex arc does not have the components in the given order of receptors----muscles----sensory neuron----motor neuron----spinal cord.

Option B:

Reflex arc does not have the components in the given order of receptor----motor neuron----spinal cord----sensory neuron----muscle.

Option C:

Reflex arc does not have the components in the given order of receptor----spinal cord----sensory neuron----motor neuron----muscle.

Final answer: The correct sequence of the components of a reflex arc is receptor----sensory neuron----spinal cord----motor neuron----muscle.