Neurophysiology

Question 1

What is an action potential

Answer 1

brief electrical impulse resulting in membrane potential being momentarily reversed

Question 2

where is the site of initiation of the all or none action potential in a neuron

Answer 2

axon hillock

Question 3

describe a unipolar neuron

Answer 3

1 neurite

peripheral autonomic neuron

Question 4

describe a pseudounipolar neuron

Answer 4

1 neurite that bifurcates

dorsal root ganglion

Question 5

describe a bipolar neuron

Answer 5

2 neurites

retinal neuron

Question 6

describe a multipolar neuron

Answer 6

> =3 neurites
motor neurons
LMN

Question 7

What is the overall ion movement in upstroke in an action potential

Answer 7

Na influx

Question 8

What is the overall ion movement in downstroke in action potential

Answer 8

K efflux

Question 9

what is membrane resistance

Answer 9

holes/channels that allow for ion leakage

Question 10

What is length constant

Answer 10

distance a passive process travels

Question 11

high membrane resistance means there are no leakages, true or false

Answer 11

true

Question 12

higher the membrane resistance, the higher/lower the axoplasm resistance, the higher/lower the length constant

Answer 12

higher the membrane resistance, lower the axoplasm resistance, higher the length constant

Question 13

increasing axon diameter increases/decreases axoplasm resistance

Answer 13

decreases

Question 14

adding an insulating material increases/decreases membrane resistance

Answer 14

increases

Question 15

myelinated axons conduct faster than non-myelinated axons, true or false

Answer 15

true

Question 16

2 ways of increasing passive current spread

Answer 16

decrease axoplasm resistance with thicker axons

increase membrane resistance with myelin

Question 17

What types of synapses exist

Answer 17

axodendritic - commonest
axosomatic
axoaxonic - least common

Question 18

What is the major excitatory neurotransmitter

Answer 18

glutamine

Question 19

in the excitatory synapses, what are the properties of the receptor

Answer 19

cation, selective, ionotropic, glutamate receptors

Question 20

what are the major inhibitory neurotransmitters

Answer 20

GABA

glycine

Question 21

in the inhibitory synapse, what are the properties of the receptor

Answer 21

anion, selective, ionotropic, GABA/glycine receptors

Question 22

Of which ion is there an influx in epsp

Answer 22

Na+ influx

Question 23

Of which ion is there an influx in ipsp

Answer 23

Cl- influx

Question 24

What types of gating are present in neurotransmitter receptors

Answer 24

direct gating

indirect gating

Question 25

What receptor is involved in direct gating

Answer 25

ionotropic receptors

Question 26

What are ionotropic receptors and how fast is transmission

Answer 26

receptors that are also channels | rapid transmission

Question 27

What receptor is involved in indirect gating

Answer 27

metabotropic receptors

Question 28

What are metabotropic receptors and how fast is transmission

Answer 28

receptor with NO channel | slow transmission

Question 29

NMDA receptors are permeable to which ions

Answer 29

Ca, Na, K

Question 30

Non-NMDA receptors are permeable to which ions

Answer 30

Na, K