Reflex action

Definition

Reflex action is an involuntary and nearly instantaneous movement in response to a stimulus. It involves a direct pathway through the spinal cord, bypassing the brain for faster response.

5 Must Know Facts For Your Next Test

1. Reflex actions are crucial for survival as they provide quick responses to potentially harmful stimuli.
2. They are controlled by the autonomic nervous system, which regulates involuntary bodily functions.
3. Reflex arcs consist of five main components: receptor, sensory neuron, interneuron, motor neuron, and effector.
4. Examples include the knee-jerk reaction and the withdrawal reflex when touching something hot.
5. Reflexes can be either innate (inborn) or acquired through conditioning.

Review Questions

• What are the five main components of a reflex arc?
• How do reflex actions differ from voluntary actions in terms of neural pathways?
• Give two examples of reflex actions and explain their importance.

Related terms

Stimulus: A detectable change in the internal or external environment that elicits a response.

Autonomic Nervous System: The part of the nervous system responsible for controlling involuntary bodily functions such as heart rate and digestion.

Interneuron: A neuron that transmits impulses between other neurons, especially as part of a reflex arc.