Biopsychology: Neurons and synaptic transmission

Question 1

Types of neurons

Answer 1

Sensory neurons
Motor neurons
Relay neurons

Question 2

Sensory neurons

Answer 2

Receptor -> CNS

Carry nerve impulses FROM sensory receptors TO CNS

Question 3

Where are sensory neurones located?

Answer 3

upper epidermis - connected to receptors

Question 4

Relay neurons (interneurone)

Answer 4

CNC -> CNS
Connect sensory and motor neurones, to other relay neurones
Carry messages from one part of CNS to another
SHORT A SHORT D

Question 5

Where are relay neurones located?

Answer 5

In CNS

Question 6

Motor neurons

Answer 6

Carry electrical impulses away from CNS via long axons to muscles/glands. Causes muscle/ glad to react
LONG A SHORT D

Question 7

Where are motor neurones located?

Answer 7

In CNS

Question 8

What is a neuron?

Answer 8

A specialised cell

Question 9

Dendrites

Answer 9

Where info is received and processed

Carry nerve impulses from neighbouring neurones towards the cell body

Question 10

Axon

Answer 10

Carry electrical impulse AWAY from cell body, down the length of the neuron

Question 11

Myelin Sheath

Answer 11

An insulating substance which covers axons to help convey the nerve impulse rapidly and protect the axon

Question 12

Nodes of Ranvier

Answer 12

Gaps in the myelin sheath which speed up transmission of impulse.
Allows action potential to effectively ‘jump’ from node to node

Question 13

Axon terminal

Answer 13

Transmits a neurotransmitter from one neuron to another

Question 14

Cell body (soma)

Answer 14

Includes a nucleus containing genetic material

Question 15

Example of an excitatory neurotransmitter

Answer 15

Adrenaline

Question 16

Excitatory neurotransmitters will

Answer 16

Will increase the + charge on the post-synaptic neuron, making impulse more likely to fire

Question 17

Example of an inhibitory neurotransmitter

Answer 17

Serotonin

Question 18

Inhibitory neurotransmitters will

Answer 18

Will increase the - charge on the post-synaptic neuron, making impulse less likely to fire

Question 19

What does the firing of an impulse depend on?

Answer 19

The sum of excitatory and inhibitory signals it receives
Net effect excitatory = neuron more likely to fire an impulse
Net effect inhibitory = neuron less likely to fire an impulse

Question 20

How is an electrical impulse created? (firing of a neuron)

Answer 20

Neuron resting state = inside of cell - charged compared to outside
Neuron activated = inside of cell + charged for split second.
Causing an action potential to occur.
This creates and electrical impulse
Impulse travels down the axon towards the end of the neuron

Question 21

Synaptic transmission

Answer 21

The process of information transfer across a synapse

Question 22

Summation

Answer 22

Excitatory or inhibitory effect on neighbouring neuron

Question 23

Resting state

Answer 23

The state in which there is a negative electrical charge within the neuron

Question 24

Action potential

Answer 24

a neural impulse; a brief electrical charge that travels down an axon

Question 25

Synaptic vesicles

Answer 25

Sac-like structures that release neurotransmitters

Question 26

Outline the structure and processes of synaptic transmission (6 marks)

Answer 26

Structure: neurones are separated by a synapse - a gap between neurons.

1) When an electrical impulse reaches end of neuron
2) Triggers release of NT’s from synaptic vesicles
3) NT chemically diffuses across the synapse and bind to receptors on the post-synaptic receptor site on the next neuron
- Each NT has its own specific molecular structure that corresponds to ‘fit’ into a post-synaptic receptor site
4) Electrical impulse continues and next transmission begins

TALK ABOUT SUMMATION - NT’s can have excitatory/inhibitory effects on neighbouring neuron:
Excitatory (e.g. adrenaline) = increase + charge on post-s neuron, increase likelihood of it firing
Inhibitory (e.g. serotonin) = increase - charge on post-s neuron, decrease likelihood of it firing

5) reuptake: neurotransmitter is reabsorbed in vesicles in pre-synaptic cell after performing function of transmitting electrical impulse

Question 27

Neurotransmitters

Answer 27

diffuse across synapse to the next neuron

Question 28

How are signals within neurons transmitted?

Answer 28

electrically

Question 29

How are signals between neurons transmitted?

Answer 29

Chemically

Question 30

Synapse

Answer 30

a gap between 2 neurons