Reflex action (& reflex arc) | Control & Coordination | Biology | Khan Academy
Khan Academy India - English・2 minutes read
Various stimuli trigger involuntary reflex actions, such as moving away from heat or raising a leg, which do not require conscious decision-making and involve only three neurons and the spinal cord for immediate response. These reflex actions involve a sensory neuron detecting the stimulus, a relay neuron transferring the signal, and a motor neuron activating the muscle for action, bypassing the brain in a unique loop shape always connecting to the back of the spinal cord.
Insights
- Reflex actions are automatic responses triggered by stimuli like heat or light, bypassing conscious thought and involving only three neurons and the spinal cord for immediate reaction.
- The sensory neuron detects the stimulus, the relay neuron transfers the signal, and the motor neuron activates the muscle, showcasing a rapid and efficient reflex arc that prioritizes quick responses over conscious decision-making.
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Recent questions
What are reflex actions?
Involuntary responses to stimuli, like sneezing or moving away.
How do reflex actions work?
They involve three neurons and the spinal cord.
What triggers reflex actions?
Changes in temperature, light, smell, and pressure.
Are reflex actions conscious decisions?
No, they do not require conscious decision-making.
What is the role of sensory neurons in reflex arcs?
They detect stimuli and connect to the spinal cord.
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Summary
00:00
"Involuntary Reflex Actions: Immediate Responses to Stimuli"
- In four videos, various stimuli trigger involuntary reflex actions: changes in temperature, light, smell, and pressure.
- Reflex actions are automatic responses to stimuli, such as moving away from heat, sneezing, or raising a leg.
- These responses are involuntary and do not require conscious decision-making, known as reflex actions.
- The mechanism of a reflex action involves only three neurons and the spinal cord, bypassing the brain for immediate response.
- The sensory neuron detects the stimulus, the relay neuron transfers the signal, and the motor neuron activates the muscle for action.
- Reflex arcs consist of sensory, relay, and motor neurons, with sensory neurons having a unique loop shape and always connecting to the back of the spinal cord.
