Neurons and synaptic transmission

Question 1

What are neurons

Answer 1

Cells that conduct nerve impulses through electrical and chemical messages

Question 2

Describe the function of sensory neurons

Answer 2

Carries messages from the environment and peripheral NS to the CNS. Long dendrites and short axons

Question 3

Describe the function of relay neurons

Answer 3

Transfers messages from sensory neurons to other neurones/motor neurones . Short dendrites and short axon

Question 4

Describe the function of motor neurones

Answer 4

Carries messages from CNS to muscles and glands
Short dendrites and long axon

Question 5

Describe the function of the nucleus

Answer 5

Control centre of a cell/contains cell’s DNA

Question 6

Describe the function of the dendrites

Answer 6

Receives nerve impulse or signal from other neurons

Question 7

Describe the function of the axon

Answer 7

Where electrical signals pass along

Question 8

Describe the function of the myelin sheath

Answer 8

Protects axon from external influences that could affect transmission of nerve impulse along axon

Question 9

Describe the function of nodes of ranvier

Answer 9

Speeds up transmission of the impulse by forcing it to jump

Question 10

Describe the function of terminal buttons

Answer 10

Sends signals to adjacent cells

Question 11

What is an excitatory action potential

Answer 11

Neurotransmitter increases likelihood that neuron will fire and pass electric impulse to next neurone

Question 12

What is an inhibitory action potential

Answer 12

Neurotransmitter decreases likelihood neuron will fire and pass electric impulse to next neuron.

Inhibitory neurotransmitters generally responsible for calming the mind and body e.g. GABA released by brain after stress to calm the body/brain

Question 13

What is summation

Answer 13

Way of achieving action potential
Net effect of excitatory and inhibitory changes
Affected by amount of charge from presynaptic neurons/speed of charges