Very Short Question and Answers - Reflex Action and Reflex Arc

A reflex action is a sudden, automatic, and involuntary response to a stimulus that does not involve the conscious part of the brain.

Pulling your hand away after touching something hot and blinking your eyes when an object comes near them.

Reflex actions protect the body from harm by enabling quick responses to harmful stimuli, often faster than conscious thought.

A reflex arc is the pathway taken by nerve impulses to produce a reflex action.

Receptor, sensory neuron, relay neuron (in spinal cord), motor neuron, effector.

Receptors receive the stimulus from the environment and generate nerve impulses.

The relay neuron is present in the spinal cord.

The spinal cord mainly controls reflex actions.

The effector (muscle or gland) acts in response to the nerve impulse, producing the reflex action.

When you touch a hot object, the skin receptors feel the heat, sensory neurons carry the impulse to the spinal cord, relay neurons transmit the message to motor neurons, which then make muscles contract to withdraw your hand quickly.

False. Most reflex actions are controlled by the spinal cord, not the brain.

Sensory neurons transmit nerve impulses from the receptor to the spinal cord.

The reflex arc forms a direct pathway through the spinal cord, bypassing the brain, allowing for a rapid response.

Blinking of the eyes when something comes close suddenly helps protect the eyes.

Reflex action is automatic and involuntary, while voluntary action is consciously controlled by the brain.

A stimulus, such as heat, pain, or light, initiates a reflex action.

The motor neuron carries impulses from the central nervous system to the effector.

A cat pulling its paw away from a thorn is an example of a reflex action in animals.

If the reflex arc is damaged, the body would not be able to respond quickly and automatically to harmful stimuli, increasing the risk of injury.

Reflex action is the response itself, whereas the reflex arc is the specific pathway the nerve impulse travels to produce that response.