neurons and synaptic transmission

Question 1

motor neuron

Answer 1

carry messages from the CNS to muscles and glands (for secreting hormones or other chemicals)

Question 2

sensory neurons

Answer 2

carry messages from the PNS to CNS
have long dendrites and short axons

Question 3

relay neurons

Answer 3

carry messages from sensory neurons to motor neurons, or to other relay neurons
have short dendrites and long axons

Question 4

cell body

Answer 4

includes a nucelus which contains the genetic material of the cell

Question 5

dendrite

Answer 5

branch like structure protruding from the neighbouring neurons towards the cell body

Question 6

myelin sheath

Answer 6

the axon is covered in a fatty layer of myelin sheath that protects it

Question 7

axon terminals

Answer 7

at the end of the axon and communicate with the next neurons

Question 8

axon

Answer 8

carries the impulses away from the cell body down the length of the neuron

Question 9

nodes of ranvier

Answer 9

segments the myelin sheath to speed up the transmission of the impulse by forcing it to ‘jump’ across the gaps axon by axon

Question 10

terminal buttons

Answer 10

these are at the end of each axon and communicate with the next neuron

Question 11

inhibitory effect

Answer 11

some neurotransmitters make the neuron more negatively charged so less likely to fire e.g serotonin

Question 12

excitatory effect

Answer 12

increase in the positive charge so the neuron is more likely to fire e.g adrenaline

Question 13

electrical transmission

Answer 13

• when a neuron is in a resting state the inside of a cell is negatively charged compared to the outside
• when it is activated by a stimulus, the inside of the cell becomes positively charged for a split second causing action potential to happen — this creates an electrical impulse that travels down the axon towards the end of the neuron