Biopsychology- Neurons & Synaptic transmission

Question 1

What are neurons?

Answer 1

The cells making up the nervous system, which conduct electrical impulses

Question 2

What do dendrites do?

Answer 2

Receive signals from other neurons or sensory receptors

Question 3

What is the cell body?

Answer 3

Control centre of the neuron

Question 4

What does the axon do?

Answer 4

Conducts nerve impulses away from cell body and towards other neurons

Question 5

What structure do sensory neurons have?

Answer 5

Mostly unipolar- have a cell body, with two stems on either side

Question 6

What do sensory neurons do?

Answer 6

Carry sensory information from the body’s sensory receptors to the brain

Question 7

What are the 3 main types of neurons?

Answer 7

1) Sensory neurons
2) Motor neurons
3) Relay neurons

Question 8

What is the structure of motor neurons?

Answer 8

Mostly multipolar neurons- single axon & many dendrites

Question 9

What is the function of motor neurons?

Answer 9

Carry motor commands from CNS to skeletal muscles or glands, allowing control of movement and responses of internal systems

Question 10

What structure do relay neurons have?

Answer 10

Mostly multipolar-have a cell body surrounded entirely by dendrites

Question 11

What do relay neurons do?

Answer 11

Pass messages to other neurons within the CNS and allow sensory and motor neurons to communicate with each other

Question 12

What are nerve impulses also known as?

Answer 12

Action potential

Question 13

Where do neurons transmit information?

Answer 13

Within the neuron and from one neuron to another

Question 14

What parts of neurons receive info and where from?

Answer 14

Dendrites from sensory receptors

Question 15

What does information travel across the body in the form of?

Answer 15

Nerve impulse/ action potential

Question 16

What does the process of synaptic transmission refer to?

Answer 16

The process by which a nerve impulse passes across the synaptic cleft from one neuron (presynaptic neuron) to another (postsynaptic neuron)

Question 17

What is the synapse?

Answer 17

Small gap between neurons- end of one & dendrite/cell body of another in which neurotransmitters are released, permitting nerve impulses to travel between them

Question 18

What is included in the synapse region?

Answer 18

1) End of pre-synaptic
2) Membrane of post-synaptic neuron
3) Synaptic gap

Question 19

What are neurotransmitters?

Answer 19

Chemical substance that transmits nerve impulses across a synapse

Question 20

What is the synaptic transmission?

Answer 20

Transmission of nerve impulses across the synapse

Question 21

How long does a synaptic transmission take?

Answer 21

A fraction of a second

Question 22

What is the first step in synaptic transmission?

Answer 22

Synaptic vesicles that store neurotransmitters move to the end of the axon

Question 23

What is the second step in synaptic transmission?

Answer 23

As the nerve impulse goes down the axon, it stimulates the vesicles to release the neurotransmitter molecules into the synapse

Question 24

What is the third step in synaptic transmission?

Answer 24

The neurotransmitter molecules diffuse across the synaptic cleft to the post-synaptic membrane of the next neuron & bind to specialised receptors activated by that particular neurotransmitter

Question 25

What does the process of synaptic transmission produce?

Answer 25

Excitatory or inhibitory effects of on the postsynaptic neuron

Question 26

How many receptors can most neurotransmitters bind to?

Answer 26

Various types e.g. serotonin can bind to at least 10 types

Question 26

What happens after synaptic transmission?

Answer 26

The neurotransmitter is released back into the synaptic space, then it is cleared from the synaptic cleft

Question 27

What processes clear the neurotransmitter from the synaptic cleft after synaptic transmission?

Answer 27

1) Diffusion- some of it drifts away
2) Break-down- some of it is broken down by enzymes
3) Re-uptake-some of it is taken back up into the presynaptic neuron, repackaged & stored for later

Question 28

What are two types of neurotransmitter?

Answer 28

1) Excitatory
2) Inhibitory

Question 29

What does an excitatory neurotransmitter do?

Answer 29

Binds with postsynaptic receptor, causing an electrical change in the cell membrane- resulting in an excitatory postsynaptic potential (EPSP) making the postsynaptic cell more likely to fire

Question 30

What does an inhibitory neurotransmitter do?

Answer 30

Binds with a postsynaptic receptor, resulting in an inhibitory postsynaptic potential (IPSP) making the postsynaptic cell less likely to fire

Question 31

Can a nerve cell receive excitatory and inhibitory neurotransmitters at the same time?

Answer 31

Yes

Question 32

What determines whether a neuron fires or not?

Answer 32

Sum of all the excitatory and inhibitory synaptic input for the postsynaptic cell