neuronal communication

Question 1

which ion is the cell membrane most leaky to

Answer 1

K+

Question 2

what[’s the resting membrane potential?

Answer 2

-70 mV

Question 3

what makes the extracellular environment more negative

Answer 3

Cl-, proteins which are negatively charged

Question 4

how many voltage-sensitive gates does the Na+ pore have and what do they do when

Answer 4

2 gates. activation gate and inactivation gate
resting:
* A gate closed
* I gate open

depolarisation:
* both gates open
* THEN inactivation gate closes slowly (1ms after depolarisation)

Repolarisation
* A gate closes
* I gate opens

Question 5

how many voltage-sensitive gates does the K+ pore have and what do they do when

Answer 5

one gate, usually closed
Opens slowly in response to depolarisation. stays open resulting in in hyperpolarisation

Question 6

where is the trigger site of an action potential

Answer 6

AXON HILLOCK

Question 7

what does autonomic menan

Answer 7

not under conscious control
controlled from the brainstem by mechanisms not amenable to conscious control

Question 8

what are the two important plexi in the enteric nervous system and what do they do

Answer 8

myenteric: ennervates the muscles - peristalsis submucosal: control secretion

Question 9

what are the 4 types of nerves in teh enteric plexi

Answer 9

sensory afferent nerves, interneurones, secretomotor neurones, motor neurones

Question 10

name and describe 3 proteins associated with neurotransmitter release at nmj

Answer 10

VAMP in vesicle membrane and Syntaxin and SNAP25 in synaptic membrane make the SNARE complex which anchors the vesicle to the membrane

Question 11

what are the 2 types of post synaptic receptors

Answer 11

ligand gated and G protein coupled

Question 12

what do ligand gated receptors do and where are they?

Answer 12

on teh cell surface when the ligand binds, ion channels open

Question 13

what to G coupled Protein receptors do and where are they

Answer 13

inside the membrane but they recognise external signals
all sorts of intracellular effects including opening OR closign ion channels

Question 14

name a receptor that will cause depolarisation of the post-synaptic neurone when activated

Answer 14

nicotinic acetyl choline (nAchR)

Question 15

name a neurotransmitter receptor that will cause hyperpolarisation of the post-synaptic neurone when activated

Answer 15

GABA alpha

Question 16

who regulates ion channels

Answer 16

GPCRs

Question 17

what happens at neuro muscular junctions

Answer 17

ACh is released, always causes an action potential. There are no inhibitory NTs at NMJs

Question 18

OTHER than at NMJs, what do all other synapses have a combination of

Answer 18

excitatory and inhibitory inputs

Question 19

where do Purkinje cells live and what do they look like

Answer 19

only cerebellar cortex, massive tree

Question 20

summation of —- and —– gives the probability of a post-synaptic action potential

Answer 20

EPSP + IPSP