Neurons (5/11)

Question 1

Negative membrane potential

Answer 1

more positive charge on the outside and less positive charge on the inside

Question 2

Potassium concentration

Answer 2

higher inside than out

Question 3

Sodium concentration

Answer 3

lower inside than out

Question 4

Chloride concentration

Answer 4

lower inside than out

Question 5

Na+K+ATPase

Answer 5

3 sodium out and bring 2 potassium in by hydrolyzing ATP

Question 6

Resting membrane potential

Answer 6

-70 mV

Question 7

Depolarization

Answer 7

the membrane potential becomes less negative and approaches 0

Question 8

OVershoot

Answer 8

the membrane potential becomes positive

Question 9

Repolarization

Answer 9

Returning to the resting membrane potential after the neuron has depolarized

Question 10

Hyperpolarization

Answer 10

The membrane potential becomes more negative than the resting membrane potential

Question 11

Signal transmission

Answer 11

neurotransmitters released in synaptic clef and binds to receptors to affect graded potential (most are excitatory-EPSP)

Question 12

Voltage gated

Answer 12

opens or closes in response to membrane potential

Question 13

Threshold potential

Answer 13

the membrane potential where voltage gated sodium channels open in a domino effect; about -55 mV

Question 14

Repolarization path

Answer 14

Potassium channels open up and Na channels close

potassium is rushing out to make negative again

Question 15

Absolute refractory period

Answer 15

new action potential will not initiate

Na channels cannot open immediately

Question 16

Ca2+ voltage gated channels

Answer 16

Taken up in vesicles

neurotransmitters either undergo degradation or reuptake

Question 17

Membrane resistance

Answer 17

ability to keep charges separate

high membrane resistance= effective action potential transmission

Question 18

Cytoplasmic resistance

Answer 18

How much the cytoplasm itself impedes the flow of ions
more resistance= less conduction
Larger neuron= less resistance

Question 19

Larger neurons

Answer 19

lower cytoplasmic resistance
higher capacitance
faster at conducting signals
harder to depolarize

Question 20

Smaller neurons

Answer 20

higher cytoplasmic resistance
lower capacitance
slower at conducting signals
easier to depolarize

Question 21

Myelination

Answer 21

prevent reflux
increases membrane resistance
decreases capacitance
conduction is extremely rapid

Question 22

Nerst equation

Answer 22

Ecell=E0 - lnQ x RT/nF

Question 23

natural log of 1

Answer 23

zero

Question 24

Action potential

Answer 24

flow of ions

Question 25

Electrical potential energy

Answer 25

charge separation

Question 26

Chemical potential energy

Answer 26

ATP hydrolysis