SB2i Neurotransmission speeds Flashcards
What are the three types of neurons and what do they do?
.sensory neurones - send impulses from receptors to the CNS
.relay neurones - send impulses across the CNS
.motor neurones - send impulses from the CNS to effector muscles to stimulate a response
What happens when the brain coordinates a response to a stimulus?
impulses are sent of effectors (muscles and glands) and these carry out an action.
What is CNS?
.central nervous system
.it is made up of the brain and the spinal cord
What makes up the rest of our nervous system?
nerves (neurones).
How can different parts of our body communicate with each other?
via electrical signals called impulses
What do receptors respond to and where are they located?
they respond to stimuli and are in our skin or concentrated in special organs
What do motor neurones have?
Dendrites, which are found in the cell body
What is a synapse?
space between 2 neurones
What happens when a impulse reaches a synapse?
chemical messengers (neurotransmitters) diffuse across the synaptic cleft and join (bind) with receptors on the next neurone, triggering another impulse
What do synapses ensure?
that the impulse only goes in one direction
What do synapses allow for new impulses?
that they dont lose ‘strength’
Why do we have a reflex arc?
to protect the body from danger
Why do reflex arc bypass the brain?
they are automatic meaning our brain doesnt process it
speed =
distance/time
What are neurotransmitters?
chemical message that diffuse between the synapse of two neurones
What is a muscle?
an effector
Describe how the arrival of an impulse at the end of one neurone can cause an impulse in a neighbouring neurone. (3 marks)
The impulse causes the release of a
chemical neurotransmitter which diffuses across the synapse and binds to receptors on the neighbouring neurone, triggering a new impulse
