Question

Define Reflex Action and explain the pathway of a Reflex Arc with an example.

Hint:

Reflex actions are controlled mainly by the {spinal cord}, allowing the body to respond quickly to harmful stimuli.

Answer 1

Concept: Reflex actions are quick, automatic responses that help protect the body from harm. These actions occur through a special neural pathway called a reflex arc, which mainly involves the spinal cord rather than the brain.
Step 1:Definition of Reflex Action Reflex action is a sudden, automatic, and involuntary response to a stimulus without the involvement of conscious thinking. Example: Quickly withdrawing the hand when it touches a hot object.
Step 2:Pathway of Reflex Arc A reflex arc is the pathway through which nerve impulses travel during a reflex action. It consists of the following components:

• Receptor: Detects the stimulus (e.g., heat receptors in the skin).
• Sensory neuron: Carries the impulse from the receptor to the spinal cord.
• Interneuron: Located in the spinal cord, processes the signal.
• Motor neuron: Carries the impulse from the spinal cord to the effector.
• Effector: The muscle or gland that produces the response.

Step 3:Example of Reflex Action When a person touches a hot object:

• Receptors in the skin detect heat.
• Sensory neurons carry the impulse to the spinal cord.
• The spinal cord sends a signal through motor neurons.
• The muscles of the hand contract, pulling the hand away quickly.