anat nervous vocab

Question 1

excitability

Answer 1

they can respond to changes in their surrounding. changes affect membrane potential by openeing gated ion channel

Question 2

stimulus

Answer 2

changes affecting membrane potential (opening a gated ion channel) membrane potential becomes more negative

Question 3

action potential

Answer 3

achieved after threshold potential is reached. neural impulse,
bigger diameter of axon, faster the impulse

Question 4

extracellular fluid

Answer 4

bodily fluid outside cell

Question 5

-70mV

Answer 5

resting potential, excess negative on inside

Question 6

+30mV

Answer 6

peak of action potential, positive on the inside (depolarization)

Question 7

-55mV

Answer 7

threshold potential, neuron depolarizing sufficiently n action potential result/nueral impulse

Question 8

threshold

Answer 8

level of stimulation required to trigger an impulse

Question 9

ion channels

Answer 9

membrane proteins whose functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of ions across the cell membrane, controlling the flow of ions

Question 10

Na+/K+ pump

Answer 10

actively transport sodium ions out of the cell and potassium ion into the cell,

potassium K: inside
sodium Na: outside

Question 11

depolarizing phase

Answer 11

more positive than resting

Question 12

all or none principle

Answer 12

muscle fiber/neuron completly responds when exposed to a stimulus of threshold strength

Question 13

refractory period

Answer 13

time period following stimulation during which a neuron or muscle fiber will not respond to a stimulus, restablish its restin potential

Question 14

repolarizing phase

Answer 14

the change in membrane potential that returns it to a negative value

Question 15

resting membrane potential

Answer 15

difference in electrical charge between inside and pitsode(volt) when its nit sending impulse

ions follow diffusion, more permeable to postassium (move out more than sodium in)
outside: more positive
inside has anions

Question 16

polarized

Answer 16

inside negative/ electrically charged

Question 17

leakage channels

Answer 17

Ion channels which are always open; responsible for the resting membrane potential

Question 18

anions

Answer 18

PO4-2

SO4-2

Question 19

embrane potential

Answer 19

potential difference acros cell membrance (mV)

difference in electrical charge between inside and outside

Question 20

leak

Answer 20

3 sodium leak into

2 potassium leak out. Na/K pump pump does the opposite to maintain balance

Question 21

hypolarize

Answer 21

membrance potential becomes more negative than resting potential

Question 22

action potential

in series

Answer 22

multipolar: first part of axon: trigger zone has voltage gated sodium, threshold: open n membrane potential: positive, vated closes quickly/ then potasium voltage open out then membrain repolarize n all gate closes

Question 23

absolute refractory

Answer 23

membrane change in sodium permeability

Question 24

relative refreactory

Answer 24

reestablishes its resting potential n stimulus w/ high intesity can trigger impulse

Question 25

impulse in unmyelinated

Answer 25

over entire surface

Question 26

myelin

Answer 26

insulator n prevent flow of ion through membrane. nodes of ranvier, channel open at here, n action potential only occure here: saltatory conduction, faster than unmyelinated

Question 27

neurotransmitter

Answer 27

react w/ receptors in postsynaptic membrance (chemically gated) changes in these channels creat synaptic potential

Question 28

synaptic potentials

Answer 28

depolarize/ hyerpolarize the recieving cell membrane

net effect determines whether action potential happen bc dendrites recieve messages from many axon

Question 29

excitatiory postsynaptic potential

Answer 29

depolarizing membrance n could trigger action potential

sodium open

Question 30

inhibitory postsynaptic potential

Answer 30

action potential not likely, hyperpolarizing

potessium open
chloride open

Question 31

neurotransmitters

Answer 31

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