Neurons and Synaptic Transmission

Question 1

What are neuron’s?

Answer 1

Cells of the nervous system that process and transmit messages through electrical and chemical signals

Question 2

What are the electrical impulses called on a neurone?

Answer 2

Action potentials

Question 3

What is the charge of a neuron in a resting state?

Answer 3

Inside of the cell is negatively charged

Question 4

What is the charge of a neuron when it is activated by a stimulus?

Answer 4

The inside of the stimulus becomes positively charged

Question 5

What is the description of a motor neuron?

Answer 5

-Form synapses with muscles and control contractions
-stimulated they bind to receptors on muscle and rigger response muscle movement

Question 6

Where are motor neurons located?

Answer 6

CNS and project axons outside the CNS to directly/indirectly control muscles

Question 7

What are the features of a motor neuron?

Answer 7

Short dendrites and long axons

Question 8

What is the description of a relay neuron?

Answer 8

-Connect with other neurons
-Allow sensory and motor neurons to communicate with each other
-impulses reach they brain they are translated into sensations

Question 9

What are the features of the relay neuron?

Answer 9

Short dendrites
Short axons

Question 10

What is the description of sensory neurons?

Answer 10

-Carry messages from sensory receptors via the PNS and CNS
-Sometimes info only travels to spinal cord, allows reflex actions to occur quickly without delay of sending impulses to brain

Question 11

What are the features of sensory neuron?

Answer 11

Long dendrites
Short axons

Question 12

Where are relay neurons found?

Answer 12

Brain and spinal cord (CNS)

Question 13

What do the motor neurone connect the CNS to?

Answer 13

Effectors such as muscles and gland

Question 14

What is the myelin sheath?

Answer 14

Fatty layer that protects the axon and speeds up electrical transmission of the action potential

Question 15

What is the cell body?

Answer 15

Control centre of the body

Question 16

What are dendrites?

Answer 16

Carry nerve impulses from neighbouring neurons or sensory receptors to the cell body

Question 17

What is the nucleus?

Answer 17

Contains all genetic material of the cell

Question 18

What are hides of ranvier?

Answer 18

Gaps in the myelin sheath that speed up transmission of the action potential by forcing the impulse to ‘jump’ across the gaps along the axon

Question 19

What is the axon?

Answer 19

Carries action potentials away from the cell body down the length of the neuron

Question 20

What are the steps in how the nervous system communicates through neurons?

Answer 20

-stimulus
-sensory receptor
-relay neuron
-motor neuron
-effector
-response

Question 21

What is the process of synaptic transmission?

Answer 21

-action potential reaches presynaptic terminal
-triggers synaptic vesicles to release neurotransmitters to synaptic gap
-diffuses across the gap
-bind to post-synaptic receptor sites
-stimulate of most-synaptic receptors converts chemical message to electrical impulse
-effects terminated by reuptake
-taken by pre-synaptic neurone stores in vesicles for later

Question 22

If a neurotransmitter is excitatory what does this cause?

Answer 22

Excitation of the post-synaptic membrane so posit-synaptic neuron is more likely to fire an electrical impulse

Question 23

If a neurotransmitter is inhibitory what does this cause?

Answer 23

Inhibition of the posy-synaptic membrane so posy-synaptic neuron is less likely to fire an electrical impulse

Question 24

What can neurotransmitters be classifies as in their action?

Answer 24

Inhibitory or excitatory

Question 25

Acetylcholine, noradrenaline is a?o

Answer 25

On switch (excitatory)

Question 26

Serotonin and GABA are?

Answer 26

Off switches (inhibitory)

Question 27

What is summation?

Answer 27

When the excitatory and inhibitory influences are summed