Neurophysiology 22%

Question 1

influx sodium, ascending phase, impulse likely, Na gates close

Answer 1

depolarization

Question 2

efflux potassium, inside membrane less positive, membrane potential towards resting, descending phase

Answer 2

repolarization

Question 3

threshold occurs

Answer 3

-55 and -50 mV

Question 4

before AP begins, polarized (largely - MP)

Answer 4

resting stage

Question 5

change in permeability of membrane

Answer 5

action potential

Question 6

excitatory NTs

Answer 6

NE, glutamate, NO

Question 7

inhibitory NTs

Answer 7

ACh, dopamine, glycine, GABA, serotonin

Question 8

inactivation gate will not reopen until

Answer 8

membrane potential is at “resting” level

Question 9

neuron sending the signal

Answer 9

presnyaptic neuron

Question 10

neuron receiving the signal

Answer 10

postsynaptic neuron

Question 11

most synapses, from axon to dendrite

Answer 11

axodendritic

Question 12

from axon to soma

Answer 12

axosomatic

Question 13

from axon to axon

Answer 13

axoaxonic

Question 14

tunnels (connexons) to connect cytosol of two cells

Answer 14

gap junctions

Question 15

synaptic delay

Answer 15

0.5 m/sec

Question 16

occurs 10,000ths of a second, Na+ channels begin to close and K+ channels open wider; rapid diffusion of K+ to exterior (re-establishes normal negative RMP)

Answer 16

repolarization stage

Question 17

permeable to Na ions as makes inside neuron “more towards positive” -90mV immediately neutralized

Answer 17

depolarization stage

Question 18

influx of sodium

Answer 18

depolarization

Question 19

efflux of potassium

Answer 19

repolarization

Question 20

no AP possible

Answer 20

absolute refractory

Question 21

AP available with increase potential

Answer 21

relative refractory

Question 22

many synapses single cell

Answer 22

spatial summation

Question 23

rapid succession of AP, few synapses

Answer 23

temporal

Question 24

strychnine poisoning binds to and blocks ___ cuases massive tetanic contractions, diagphragm cant relax, cant breathe, DIE

Answer 24

glycine receptors

Question 25

inhibitory neurons of SC that release glycine prevent excessive muscle

Answer 25

renshaw cells

Question 26

repolarization phase of AP

Answer 26

K+ efflux

Question 27

threshold for stimulation (membrane potential started at -90mV)

Answer 27

-65mV

Question 28

mechanoreceptor; pressure, encapsulated

Answer 28

end bulbs of krause

Question 29

mechanoreceptor; temp, pressure, encapsulated and multibranched, 2-5 degrees perception

Answer 29

corpuscles of ruffini

Question 30

mechanoreceptor; general touch, not encapsulated

Answer 30

merkels discs

Question 31

hair follicles when grouped togehter

Answer 31

iggo dome receptor

Question 32

mechanoreceptor; fine touch (dorsal columns), located on non-hairy skin, encapsulated

Answer 32

meissners corpuscles

Question 33

mechanoreceptor; pressure, vibration, encapsulated “phasic” quick adapting

Answer 33

pacinian corpuscles

Question 34

proprioception; stretch dynamic and static only in skeletal

Answer 34

muscle spindles

Question 35

proprioception; load or weight

Answer 35

golgi tendon organ

Question 36

proprioception; prevents excessive tension in muscle

Answer 36

golgi tendon reflex