Biopsy 3

Question 1

3 factors determine cell‘s electrical activity

Answer 1

• permeability to the ions
• ions‘ conc. gradient & electrical gradient
• when the ions move (ie. resting/depolarisation/repolarisation)

Question 2

Can action potential be summed up?

Answer 2

No

Question 3

What can be summed up?

Answer 3

EPSP, IPSP

Question 4

What is synapse?

Answer 4

Gap between presynaptic & postsynaptic neurons

Question 5

What instrument can we use to see the junction(synapse) between neurons?

Answer 5

Electron microscope

Question 6

What form a synpase?

Answer 6

termination of one neuron to the dendrites of another

Question 7

What can a specialised synapse that form between neurons and muscles do?

Answer 7

Causes muscles to contract and move

Question 8

Location of the axon that activate muscle?

Answer 8

Spinal cord

Question 9

How does ALS (Amyotrophic Lateral Sclerosis) affects neuron?

Answer 9

Myelin sheath degrade —> cannot transmit electrical signal —> restricts movement —> can cause death

Question 10

Neurotransmitters are packaged into _____ and transported along axon of the presynaptic terminal

Answer 10

vesicles

Question 11

What channel is opened due to the arrival of action potential to the synapse?

Answer 11

(Ca++) Calcium ion channel

Question 12

How are the neurotransmitters released into the synapse?

Answer 12

Ca++ enter the presynaptic neuron through the Ca++ channels and bind to the synaptic vesicles which cause neurotransmitters to be released into the synapse

Question 13

Describe the possible process that leads to mechanism changes (e.g. habitation/adaptation) in sea slugs‘ defensive manner.

Answer 13

Reduction of Ca++ influx at presynaptic terminal, so less neurotransmitters are released

Question 14

Where can you find a neurotransmitter receptor in a neuron?

Answer 14

dendrites

Question 15

How does ionotropic neurotransmitter receptor work?

Answer 15

a neurotransmitter binds to the receptor which opens the ion channel

Question 16

Name the 2 parts in ionotropic neurotransmitter.

Answer 16

• receptor

- ion channel

Question 17

How does metabotropic neurotransmitter receptor work?

Answer 17

neurotransmitter binds to a binding site —> subunit detaches and causes an ion channel to open

Question 18

How is metabotropic neurotransmitter receptor different from ionotropic neurotransmitter receptor?

Answer 18

Metabotropic neurotransmitter receptors influence ion channels indirectly and slowly.

Question 19

Differences between excitatory & inhibitory neurotransmitters.

• released at?
• causes?

Answer 19

E:

• Type 1 synapse
• influx of positive ions (Na+)

I:

• Type 2 synapse
• influx of negative ions (Cl-)

Question 20

Neurotransmitters must be removed & inactivated or there will be ____

Answer 20

prolonged activation

Question 21

Spatial integration?

Answer 21

Many pre-synaptic neurons together release enough neurotransmitters to exceed the threshold

Question 22

Temporal integration?

Answer 22

One presynaptic neurone releases many neurotransmitters many times over a period of time to exceed the threshold

Question 23

Use of Glutamate neurotransmitters

Answer 23

• excitatory

- for learning abd memory

Question 24

Use of GABA

Answer 24

brain‘s main inhibitory neurotransmitter

Question 25

Use of Dopamine

Answer 25

- both excitatory & inhibitory - movement control - reward circuit

Question 26

Use of Serotonin

Answer 26

- inhibitory | - mood & anxiety

Question 27

Use of Acetylcholine

Answer 27

- both inhibitory & excitatory | - neuro-muscular junction

Question 28

What cause Parkinson‘s disease.

Answer 28

- loss of dopaminergic neurons in the brain stem —> rigidity & trembling movements

Question 29

How do toxins poison ion channels?

Answer 29

- deactivate/inactivate ion channels —> might paralyse | - activate ion channels by lowering the threshold at which open

Question 30

How do toxins affect transmitters released?

Answer 30

- causes massive release of neurotransmitters at nerve-uscular junction —> paralysis - binds to the receptor & stop the release of excitatory neurotransmitters at neuro-muscular junction —> prevents contraction - prevents the release of inhibitory neurotransmitters in spinal cord —> hyperactivity of the muscles

Question 31

Agonist vs Antagonist

Answer 31

Agonist: - bind to the receptors - mimic the effect of neurotransmitters Antagonist: - bind to the receptors - blocks other neurotransmitters from binding

Question 32

How does drug affect uptake of neurotransmitters?

Answer 32

Bind to the receptor —> blocking and prevents the reuptake of neurotransmitters —> prolonged effects of that neurotransmitters

Question 33

Why people become addicted to drugs?

Answer 33

Many addictice drugs lead to the release of / prolonged activity of Dopamine —> pleasurable feeling from reward system