nervous system 5

Question 1

what is chemical communication between nerve cells called

Answer 1

synaptic transmission

Question 2

role of vesicles

Answer 2

contain neurotransmitters which fuse through the synaptic cleft and attach onto receptors

Question 3

process of synaptic transmission

Answer 3

• opening of Ca2+ channels
• Ca2+ inflow into the cell
• triggers process of exocytosis
• movement of vesicles towards the synaptic cleft
• fusion of vesicles with the membrane when they touch it
• neurotransmitter diffuses across the synaptic gap and attatches to receptor
• molecule detaches from the receptor

Question 4

process of synaptic transmission

Answer 4

• opening of Ca2+ channels
• Ca2+ inflow into the cell
• triggers process of exocytosis
• movement of vesicles towards the synaptic cleft
• fusion of vesicles with the membrane when they touch it
• neurotransmitter diffuses across the synaptic gap and attatches to receptor
• molecule detaches from the receptor

Question 5

deactivation of neurotransmitter

Answer 5

enzyme deactivation, break down in synaptic gap e.g. ACh broken down by acetylcholinesterase

Question 6

what are two different names of neurotransmitter in terms of their effect

Answer 6

excitatory neurotransmitter (boosts activity)
inhibitory neurotransmitter (suppresses activity)

Question 7

example of excitatory neurotransmitter

Answer 7

ACh acetylcholine

Question 8

what happens when ACh attaches to receptor ?

Answer 8

1) ACh attatches to receptor connected to chemically-gated ion channel
2) gate opens and positively charged Na+ enters
3) produces excitatory post-synaptic potential (EPSP)
4) tiny increase in positive charge inside cell (depends on how many channels have been opened)
5) if the SUMMATION of all the positive charges is big enough then the threshold has been reached and an action potential will be triggered at the initial segment.

Question 9

what is EPSP and IPSP and summation

Answer 9

EPSP is excitatory post-synaptic potential, IPSP is inhibitory post-synaptic potential,
summation is all of the chemical messages added up (excitatory + inhibitory)

Question 10

example of inhibitory transmitter

Answer 10

gamma amino butyric acid (GABA)

Question 11

what happens when GABA attached to receptor?

Answer 11

1) GABA attaches to receptor connected to chemically- gated ion channel
2) gate opens and negatively charged chloride ions enter
3) produces inhibitory post-synaptic potential (IPSP)
4) tiny increase in negative charge inside the cell (i.e. moves the cell’s charge away from the threshold level and makes it less likely to activate)