Unit 3.4 - The Cells Of The Nervous System And Neuro Transmitters

Question 1

What do sensory neurons do?

Answer 1

Take impulses from sensory receptors to the central nervous system

Question 2

What do interneurons do?

Answer 2

Transport impulses between sensory and motor neurons within the central nervous system

Question 3

What do motor neurons do?

Answer 3

Take impulses from central nervous system to and affecter e.g. a muscle or gland

Question 4

Why does myelination increase the speed of impulse transmission

Answer 4

Axon fibres are covered in myelin sheath which insulates the axon and speeds up impulse conduction

Question 5

When does myelination increase from?

Answer 5

From birth to adolescence

Question 6

What can certain diseases do to the myelin sheath?

Answer 6

Destroy it causing a loss of coordination

Question 7

What do glial cells do?

Answer 7

Support neurons and produce myelin sheath

Question 8

What is a synapse?

Answer 8

An area of communication between an axon of one neuron and a dendrite of another

Question 9

What is a neurotransmitter?

Answer 9

A chemical that relays the message from the presynaptic neuron to the postsynaptic neuron

Question 10

Describe the chemical transmission at synapse

Answer 10

• nervous impulse travels down the pre synaptic axon
• vesicles with neurotransmitters triggered to move to and fuse with presynaptic membrane
• neurotransmitter secreted into synaptic cleft
• receptors in post synaptic membrane recognise transmitter molecules and bind with them
• nervous impulse continuous along dendrite of post synaptic neuron

Question 11

Why is it important to remove neurotransmitters from the synapse?

Answer 11

To prevent continuous stimulation of postsynaptic neuron is

Question 12

What are the two types of signals?

Answer 12

Inhibitory or excitatory

Question 13

What determines whether a signal is inhibitory or excitatory?

Answer 13

Type of receptor

Question 14

What can synapses filter out?

Answer 14

Weak stimuli arising from insufficient secretion of neurotransmitters

Question 15

What must happen in order to reach the threshold on the postsynaptic membrane to transport the impulse

Answer 15

A minimum number of neurotransmitter molecules must attach to receptors in order to reach the threshold on the postsynaptic membrane to transmit the impulse

Question 16

What can I summation of a series of weak stimuli trigger?

Answer 16

Enough neurotransmitters to fire and impulse

Question 17

What can convergent pathways do?

Answer 17

Release a Knouff neurotransmitter molecules to reach threshold and trigger and impulse

Question 18

What are endorphins?

Answer 18

Neurotransmitters that stimulate neurons involved and reducing the intensity of pain

Question 19

What does endorphin production increase in response to?

Answer 19

Severe injury, prolonged exercise, stress and certain foods

Question 20

What are endorphins also connected to?

Answer 20

Feelings of euphoria obtain from activities such as eating, sex and prolonged exercise

Question 21

What is dopamine?

Answer 21

A neurotransmitter that induces feelings of pleasure and reinforces particular behaviours in the reward pathway in the brain

Question 22

What does the reward pathway involve?

Answer 22

Neurons which secrete or respond to dopamine

Question 23

When is the reward pathway activated?

Answer 23

When an individual engages in our behaviour that is beneficial to them, for example eating when hungry

Question 24

What are the two types of drugs used to treat neurotransmitters related to disorders?

Answer 24

Agonists and antagonists

Question 25

What is agonist?

Answer 25

Chemicals that bind to and stimulate specific receptors mimicking the action of a neurotransmitter at a synapse

Question 26

What are antagonists?

Answer 26

Chemicals that bind to specific receptors blocking the action of a neurotransmitter at the synapse

Question 27

What do other drugs do?

Answer 27

Inhibits the enzymes which break down neurotransmitters or inhibit reuptake at the signups causing an enhanced effect

Question 28

What are some disorders caused by changes in neurotransmitter release?

Answer 28

Alzheimer’s, Parkinson’s and some anxiety disorders

Question 29

What can recreational drugs also do?

Answer 29

Act as agonists or antagonists

Question 30

What do recreational drugs to?

Answer 30

Affect neurotransmission at synapse in the brain altering an individual’s mood, cognition, perception and behaviour

Question 31

What do most recreational drugs affect?

Answer 31

Neurotransmission in the reward pathway of the brain

Question 32

What do antagonists do?

Answer 32

Block specific receptors causing nervous system to increase sensitivity and number of receptors and as a consequence results in addiction

Question 33

What do agonists do?

Answer 33

Stimulate specific receptors causing the nervous system to decrease sensitivity and number of receptors and as a consequence results in drug tolerance also known as desensitisation