biopsychology 1.2

Question 1

neurons

Answer 1

electrically excitable cells that transmit signals throughout the body

Question 2

7 parts of a neuron

Answer 2

cell body/soma

nucleus

dendrites

myelin sheath

axon

axon terminal

nodes of ranvier

Question 3

cell body/soma

Answer 3

the largest part of the neuron

it contains the nucleus and the cytoplasm

Question 4

nucleus

Answer 4

contains the genetic information

Question 5

dendrites

Answer 5

extensions from the neuron’s cell body receive incoming nerve impulses from other neurons

Question 6

myelin sheath

Answer 6

the insulation membrane that surrounds an axon

helps to speed neural processes

Question 7

axon

Answer 7

long extension from the neuron’s cell body which carries outgoing nerve impulses toward other neurons

Question 8

axon terminal

Answer 8

the axon end of the terminal where nerve impulses are transmitted to the dendrites of other neuron

Question 9

nodes of ranvier

Answer 9

segmented gaps between myelin sheath that speed up the transmission of the impulse

Question 10

how do neurons work?

Answer 10

neurons form the nervous system and use nerve impulses to rapidly mass messages around the body

from the cell body, an impulse is carried down the axon as an ‘action potential’ which is an electrical signal along the axon from the cell body to the axon terminals

Question 11

3 types of neurons

Answer 11

sensory
relay
motor

Question 12

sensory neuron dendrites

Answer 12

long

Question 13

sensory neuron axons

Answer 13

short

Question 14

what do sensory neurons do?

Answer 14

take information from the sensory site to the spinal cord and are found in various locations around the body

Question 15

where do sensory neurons travel?

Answer 15

from the sensory site e.g. skin to the central nervous system (cns)

Question 16

what action are sensory neurons involved in?

Answer 16

they convert senses to neural impulses

once they reach the cns, they convert these neural impulses into sensations

these would begin a reflex

Question 17

where is the soma in the sensory neuron found?

Answer 17

outside the CNS

Question 18

what do relay neurons do?

Answer 18

communication between sensory and motor neurons

Question 19

where do relay neurons travel?

Answer 19

they are found in the spinal cord sending messages between sensory neurons and motor neurons

Question 20

relay neurons dendrites

Answer 20

short

Question 21

relay neurons axons

Answer 21

short

Question 22

what action are relay neurons involved in?

Answer 22

they are found within the brain and spinal cord and are used to communicate

they are the thinking, feeling and deciding neuron

Question 23

where is the soma of the relay neuron found?

Answer 23

inside the CNS

Question 24

what do motor neurons do?

Answer 24

they begin in the CNS but project back out to the muscles

Question 25

where do motor neurons travel?

Answer 25

they travel away from the CNS towards the skeletal muscles

Question 26

what action are motor neurons involved in?

Answer 26

their role is to control muscles by sending messages from the CNS to inform the muscles to expand or contract

Question 27

motor neurons dendrites

Answer 27

short

Question 28

motor neurons axons

Answer 28

long

Question 29

where is the soma of the motor neuron found?

Answer 29

inside the CNS

Question 30

order of neurons

Answer 30

sensory
relay
motor

Question 31

connection of the neurons

Answer 31

these neurons work as part of a system to respond to the environment

the sensory neuron begins the process by detecting a change in the environment, for example touching a hot object

a message is sent through to a relay neuron in the central nervous system where are decision is made to move away from the hot object

therefore a signal is sent through a motor neuron away from the central nervous system to a muscle

this is in order to change something, in this case, moving your hand by contracting the bicep

this process happens extremely quick as it forms part of a reflex response

Question 32

neurotransmitters

Answer 32

chemicals that diffuse across the synapse to the next neuron in the chain

Question 33

synaptic transmission

Answer 33

neurotransmitters are chemicals that diffuse across the synapse to the next neuron in the chain

once the neurotransmitter crosses the gap, it is taken up by the post-synaptic receptor site - in other words, the dendrites of the next neuron

here, the chemical message is converted back into an electrical impulse and the process of transmission begins again in this other neuron

Question 34

excitatory neurotransmitters

Answer 34

some neurotransmitters trigger other neurons which increase activity in the brain and body

excitatory neurotransmitters “excite” the neuron and cause it to “fire off the message”, meaning the message continues to be passed along to the next cell
e.g. glutamate

if the neurotransmitter is excitatory then the post synaptic neuron is more likely to fire an impulse

positive

Question 35

what happens if the neurotransmitter is excitatory?

Answer 35

if the neurotransmitter is excitatory then the post synaptic neuron is more likely to fire an impulse

Question 36

inhibitory neurotransmitters

Answer 36

some neurotransmitters inhibit other neurons which decreases activity in the brain and body

inhibitory neurotransmitters block or prevent the chemical message from being passes along any further e.g. serotonin, GABA

if the neurotransmitter is inhibitory, then the post synaptic neuron is less likely to fire an impulse

Question 37

what happens if the neurotransmitter is inhibitory?

Answer 37

if the neurotransmitter is inhibitory, then the post synaptic neuron is less likely to fire an impulse

Question 38

describe chemical transmission

Answer 38

neurons communicate with each-other within groups known as neural networks

each neuron is separated from the next by a tiny gap called the synapse

signals within neurons are transmitted electrically, however signals between neurons are transmitted chemically across the synapse

when the electrical impulse reaches the end of the neuron (the presynaptic terminal) it triggers the release of neurotransmitters from tiny gaps called synaptic vesicles

Question 39

summation

Answer 39

the addition of positive and negative post-synaptic potentials

a nerve cell can receive both positive and negative potentials simultaneously

these potentials are summed

if the net effect on the post-synaptic neuron is inhibitory, the neuron will be less likely to fire

if the net effect is excitatory, the neuron will be more likely to fire

Question 40

outline the structures and processes involved in synaptic transmission

Answer 40

information travels down a neuron through an electrical impulse called the action potential

when the message reaches the end of the neuron, called the axon terminal this message needs to be converted to a chemical message to be transferred to the next neuron

the presynaptic neuron will release neurotransmitters (chemicals) from synaptic vesicles in the axon

these neurotransmitters will then travel across the synapse and are then absorbed by the dendrites on the postsynaptic neuron

this message then transfers back into an electrical impulse to travel down the neuron

neurotransmitters can be excitatory e.g. dopamine which means the post-synaptic neuron is more likely to fire an impulse

they can also be inhibitory e.g. serotonin which means the post-synaptic neuron is less likely to fire an impulse