the structure and function of neurons

Question 1

what are the 3 different types of neurons ?

Answer 1

• motor neuron
• sensory neuron
• relay neuron

Question 2

draw and label a motor neuron

Answer 2

• dendrite
• cell body
• myelin sheath
• axon
• neurofibril node ( node of ranvier)

Question 3

draw and label a sensory neuron

Answer 3

• receptor cell
• axon
• myelin sheath
• cell body

Question 4

draw and label a relay neuron

Answer 4

• dendrite
• cell body
• axon
• pre-synaptic terminal

Question 5

what does a cell body contain ?

Answer 5

a nucleus

Question 6

what is the function of the nucleus in the cell body ?

Answer 6

it contains genetic material of the cell

Question 7

what is the function of dendrites ?

Answer 7

they carry nerve impulses from neighbouring neurons towards the cell body

Question 8

what is the function of the axon ?

Answer 8

the axon carries the impulse away from the cell body down the length of the neuron

Question 9

function of the myelin sheath ?

Answer 9

protects the axon an speeds up electrical transmission of the impulse

Question 10

what do the nodes of ranvier do ?

Answer 10

these speed up the transmission of the impulse by forcing it to jump across the gap along the axon

Question 11

what is the function of the pre-synaptic terminals ?

Answer 11

they communicate with the next neuron in the chain across a gap known as the synapse

Question 12

sensory neurons

Answer 12

• send info from senses to the brain
• tell the rest of the brain about the external and internal environment by processing info taken from one of the sense organs

Question 13

relay neurons

Answer 13

• connects with other neurons
• carry messages from one part of the CNS to another
• connects motor and sensory neurons

Question 14

motor neurons

Answer 14

• send messages via long axons from the brain to the muscles / effectors
• carry signals from the CNS, which helps both organs including glands and muscles to function

Question 15

what is involved in synpatic transmission ?

Answer 15

• synaptic vesicle
• neurotransmitters
• pre-synaptic ending / axon terminulus
• synaptic gap
• post-synaptic neuron or dendrite
• receptor sites

Question 16

what are synaptic vesicles ?

Answer 16

• small sacs that develop in the axon terminals and contain neurotransmitters specific to that neuron

Question 17

what are neurotransmitters ?

Answer 17

these ae the chemical messengers that are transmitted from the pre to post synaptic neuron

Question 18

what is the pre-synaptic ending ?

Answer 18

• the end of a neurons axon where an electrical impulse is turned into a chemical message

Question 19

what us the function of a synaptic gap ?

Answer 19

gap that the chemical messages passes across

Question 20

what is the post-synaptic neuron / dendrite ?

Answer 20

• if enough excitory neurotransmitters are received , the chemical message is turned into an electrical signal to transmit along the dendrite of the next neuron

Question 21

what is the function of receptor sites ?

Answer 21

• neurotransmitters are received by their counter part receptors on the post synaptic membrane based on the level of excitors and inhibitors received
• summation determines whether the post synaptic neuron will fire