Exam 2 key terms

Question 1

Chemical Driving Force:

Answer 1

The force exerted on molecules due to a concentration gradient, causing molecules to move from areas of high concentration to low concentration.

Question 2

Electrical Driving Force:

Answer 2

The force exerted by the electrical charge difference across a membrane, influencing the movement of charged ions toward opposite charges.

Question 3

Electrochemical Driving Force:

Answer 3

The combined effect of the chemical and electrical driving forces on ion movement across a membrane

Question 4

Leak Channel:

Answer 4

A type of ion channel that is always open, allowing ions to move freely down their concentration gradient

Question 5

Ligand-Gated Channel:

Answer 5

A type of ion channel that opens in response to the binding of a specific chemical (ligand) to a receptor site.

Question 6

Voltage-Gated Channel

Answer 6

A type of ion channel that opens or closes in response to changes in membrane potential (voltage changes).

Question 7

Regulation of Ion Movement:

Answer 7

The process by which ion channels and pumps control the movement of ions across cell membranes to maintain cellular homeostasis.

Question 8

Membrane Potential:

Answer 8

The difference in electrical charge between the inside and outside of a cell, measured across the cell membrane.

Question 9

Resting Membrane Potential:

Answer 9

The membrane potential of a cell when it is not actively sending signals, typically around -70mV for neurons

Question 10

Na+/K+ Pump

Answer 10

A membrane protein that actively transports sodium (Na+) out of the cell and potassium (K+) into the cell, helping maintain resting membrane potential.

Question 11

Polarization

Answer 11

The state of a membrane when there is a difference in charge between the inside and outside of the cell

Question 12

Depolarization

Answer 12

A reduction in the membrane potential, where the inside of the cell becomes less negative relative to the outside, often due to Na+ influx.

Question 13

Repolarization:

Answer 13

The return of the membrane potential to its resting value after depolarization, often due to the efflux of K+ ions.

Question 14

Hyperpolarization:

Answer 14

An increase in membrane potential, where the inside of the cell becomes more negative than the resting potential.

Question 15

Graded Potential:

Answer 15

A small, temporary change in membrane potential that varies in magnitude and dissipates as it travels, typically occurring in dendrites and cell bodies.

Question 16

Temporal Summation:

Answer 16

The summing of postsynaptic potentials generated at the same synapse in rapid succession.

Question 17

Spatial Summation:

Answer 17

The summing of postsynaptic potentials generated simultaneously at different synapses on the same neuron.

Question 18

Action Potential

Answer 18

A rapid, temporary change in a cell’s membrane potential that occurs when a neuron sends an electrical signal along its axon.

Question 19

Depolarization

Answer 19

Membrane potential becomes less negative as Na+ ions rush into the cell.

Question 20

Repolarization:

Answer 20

Membrane potential returns toward the resting state as K+ ions exit the cell.

Question 21

Hyperpolarization:

Answer 21

The membrane potential becomes more negative than the resting potential, often due to excess K+ leaving the cell before channels close.

Question 22

Membrane is at resting potential, Na+ and K+ channels are closed.

Answer 22

Resting State:

Question 23

Na+ channels open, allowing Na+ to flow in, causing the inside of the cell to become more positive

Answer 23

Depolarization:

Question 24

Na+ channels close, and K+ channels begin to open.

Answer 24

Peak of Action Potential:

Question 25

K+ flows out of the cell, restoring the negative membrane potential.

Answer 25

Repolarization:

Question 26

K+ channels stay open too long, causing the membrane to become more negative than the resting potential before returning to rest.

Answer 26

Hyperpolarization:

Question 27

A stimulus that is strong enough to depolarize the membrane beyond the threshold, triggering an action potential.

Answer 27

Suprathreshold:

Question 28

Gates on ion channels (like Na+ channels) that open in response to depolarization, allowing ions to flow through the membrane.

Answer 28

Activation Gates:

Question 29

Gates on ion channels (like Na+ channels) that close after depolarization to prevent further ion flow and help end the action potential.

Answer 29

Inactivation Gates:

Question 30

The period during an action potential when no new action potential can be initiated, no matter the strength of the stimulus, because Na+ channels are inactivated.

Answer 30

Absolute Refractory Period:

Question 31

The period after the absolute refractory period when a new action potential can be triggered, but only by a stronger-than-usual stimulus, as the membrane is hyperpolarized.

Answer 31

Relative Refractory Period:

Question 32

A condition where there is an abnormally low concentration of potassium (K+) in the blood, leading to muscle weakness and potentially affecting heart function.

Answer 32

Hypokalemia:

Question 33

A condition characterized by an abnormally high concentration of potassium (K+) in the blood, which can affect the excitability of neurons and muscles.

Answer 33

Hyperkalemia: