2.10.8 Simple Reflex Arc Flashcards
Does a reflex response (also known as an involuntary response) involve the conscious part of the brain as the coordinator of the reaction
No
Awareness of a response having happened occurs when?
After the response has been carried out
Responses are therefore automatic and rapid. What does this help to do?
This helps to minimise damage to the body and aids survival
Pain-withdrawal, blinking and coughing are all examples of what?
Reflex responses that help us to avoid serious injury, such as damage to the eye or choking
A reflex arc is the pathway of what?
A reflex response (specifically, the pathway taken by electrical impulses as they travel along neurones)
Give an example of a reflex response with a pain-withdrawal reflex
When someone steps on a pin
The pin (the stimulus) is detected by what?
A (pain/pressure/touch) receptor in the skin on the person’s foot
A sensory neurone sends electrical impulses to where?
The spinal cord (the coordinator)
An electrical impulse is passed to a relay neurone where?
In the spinal cord (part of the CNS)
A relay neurone synapses with what?
A motor neurone
A motor neurone carries an impulse to where?
A muscle in the leg (the effector)
When stimulated by the motor neurone, the muscle will what?
Contract and pull the foot up and away from the sharp object (the response)
How long does this all occur?
A fraction of a second
What are the three main types of neurone in a reflex arc?
Sensory
relay
motor
Sensory neurones carry impulses from what?
Sense organs to the CNS (brain or spinal cord)
