REFLEX ACTION : it is the unconscious and involuntary response to stimulus.
REFLEX ARC : the nerve path involved in reflex action for quick response is reflex arc.

Reflex Arc and Reflex Action
Reflex arc and reflex action are essential components of the human nervous system that allow for rapid responses to stimuli without conscious thought.

Reflex Arc:
- A reflex arc is a neural pathway that controls a reflex action.
- It involves the sensory receptor, afferent neuron, interneuron, efferent neuron, and effector organ.
- When a stimulus is detected by a sensory receptor, it sends an impulse through the afferent neuron to the spinal cord.
- In the spinal cord, the interneuron processes the information and sends a response through the efferent neuron to the effector organ.
- This entire process occurs involuntarily and quickly, allowing for rapid reactions to potential harm.

Reflex Action:
- A reflex action is an involuntary and almost instantaneous response to a stimulus.
- It serves as a protective mechanism by allowing the body to respond quickly to potential threats.
- Reflex actions can be simple, such as the knee-jerk reflex, or more complex, such as withdrawing your hand from a hot surface.
- These actions do not involve the brain's conscious control but are instead coordinated by the spinal cord.
- Reflex actions help prevent injury by allowing the body to react rapidly without the need for conscious thought.
In conclusion, reflex arcs and reflex actions are vital components of the nervous system that enable rapid responses to stimuli. Understanding how these processes work can provide insight into the body's ability to protect itself from harm.