Neurons

Question 1

Neuron

Answer 1

nerve cells which process and transmit messages chemically and electrically

Question 2

Sensory neuron

Answer 2

•transmits impulses from a receptor to the spinal cord or brain
• long dendrites
• short axons

Question 3

Relay neuron

Answer 3

• allows sensory and motor neurons to communicate with each other
• short dendrites
• short axons

Question 4

Motor neuron

Answer 4

• sends impulses from the CNS to a muscle, organ or gland
• short dendrites
• long axons

Question 5

Synaptic transmission process

Answer 5

1. electrical impulse (action potential) travels down the presynaptic neuron towards the synapse
2. this triggers the release of neurotransmitters from the vesicles and into the synapse
3. the neurotransmitters diffuse across the synapses and bind with receptor sites on the post synaptic neuron
4. the chemical signal is converted back to an electrical signal to continue the process again in the post synaptic neuron
5. unused neurotransmitters are taken back up to the presynaptic neuron via reuptake valves and they go back to the vesicles to be reused on the next transmission

Question 6

Inhibition

Answer 6

A neurotransmitter that decreases the negative charge of the presynaptic neuron.
•decreases likelihood that it will fire e.g. serotonin

Question 7

Excitation

Answer 7

a neurotransmitter that increases the positive charge of the presynaptic neuron
•increases likelihood that it will fire e.g. adrenaline