Week 6- Nerve Cells

Question 1

All cells in the human body are characterized by having a net electrical charge across its membrane.

Answer 1

Membrane electrical polarization

Question 2

-60 to -100 mV

Answer 2

Resting membrane potential

Question 3

What is the resting potential determined by?

Answer 3

Concentration gradients of ions across the membrane and by membrane permeability to each type of ion.

Question 4

At rest, the Na+/K+ pump maintain this gradient

Answer 4

Resting membrane potential

Question 5

Cations (Na+) flow into the cell making the cell more positive.

The sodium channel is opened and the potassium channel is closed.

Answer 5

Depolarization

Question 6

Depolarize

Answer 6

Change in a cell’s membrane potential/voltage

Question 7

Returning the membrane potential to a negative value after the depolarization phase.

Results from the movement of positively charged potassium ions out of the cell

Answer 7

Repolarization

Question 8

Determines the amount of water inside the cell.

Answer 8

Osmolarity

Question 9

What happens during active transport?

Answer 9

Na+ carried out of the cell

K+ carried into the cell

Question 10

Surrounded by a plasma membrane

Answer 10

Cells

Question 11

Different concentrations of ions inside and outside of the nerve cell (neuron)

Answer 11

Na+, Cl- and K+

Question 12

What is the difference between the intercellular and extracellular compartments?

Answer 12

Negative

Question 13

The interior membrane is electrically ________ in relation to the exterior

Answer 13

Negative

Question 14

Nerve cells at rest

Answer 14

Electrochemical equilibrium

Cl- and Na+ ions exist in a higher concentration outside the cell than inside

K+ exists in higher concentration inside than outside the cell

Question 15

Selectively permeable

Answer 15

Nerve cell membrane