Synapses and Reflexes Flashcards
What do neurones do?
Transimit information (as electrical impulses) very quickly to and from the CNS
Reflexes are ____ than neurone transmission to the brain and decisions made from there
Reflexes are quicker than neurone transmission to the brain and decisions made from there
What is a synapse?
The connection between two neurones
Describe how nerve signals are transferred across a synapse
The nerve signal is transferred by chemicals which diffuse across the gap.
These chemicals then set off a new electrical signal in the next neurone
Reflexes help prevent ____
Reflexes help prevent injury
Define ‘reflexes’
Automatic responses to certain stimuli
Describe the reflex caused by shining a bright light in your eye
The pupil automatically gets smaller to prevent the light getting into the eye and causing damage to the retina.
Describe the reflex caused by getting a shock
Your body automatically releases the hormone adreniline
What is the passage of information in a reflex called?
A reflex arc
What is the span of a reflex arc?
From receptor to effector
Electrical impulses travel from neurone to neurone ____ ____.
Why is this important?
Electrical impulses travel from neurone to neurone really fast.
This gives you a chance of being able to respond quickly to stimuli
A reflex arc can travel through which 2 parts of the CNS?
- The spinal chord
- An unconcious part of the brain
Describe 7 the steps to a reflex arc
- A stimulus is detected by receptors
- Impulses are sent along a sensory neurone to the CNS
- When the impulse reaches a synapse between the sensory neurone and a relay neurone, they trigger chemicals to be released.
- These chemicals cause impluses to be sent along the relay neurone.
- When the impulse reaches a synapse between the relay neurone and a motor neurone, they trigger chemicals to be released.
- These chemicals cause impluses to be sent along the motor neurone to the effector.
- The effector then responds.
If a bee stings your finger, name the stimulus and the effector and response
Stimulus = pain from bee sting
Effector = muscle
Response = to contract
What are the 7 steps for a reflex arc?
- Stimulus
- Receptor
- Sensory neurone
- Relay neurone
- Motor neurone
- Effector
- Response
What do reflexes do, and when?
Reflexes bypass your concious brain completely when a quick response is essential
What reflex arcs be used to do in medicine?
(2)
To asses the conditions of:
- Unconcious casualties
or
- Those with spinal injuries
Which bodily system are doctors examining when they tap your knee with a hammer and check that you kick?
Reflex arcs
