Physiology Study Guide 7: the Cell Membrane Potential 2

Physiology Study Guide 7: The Cell Membrane Potential 2

Steven A. Fink; Instructor

PHYSIOLOGY STUDY GUIDE 7:

The Cell Membrane Potential

True/False

____ 1. The voltage that exists between the inside & outside of a cell is essentially due to the selective diffusion of K+ across the cell membrane.

____ 2. In the resting state, the inside of a cell is negatively-charged compared to the outside.

____ 3. All living cells possess an electrical voltage.

____ 4. During the resting state of cells, the voltage-gated channels for both sodium and potassium are closed.

____ 5. Hyperkalemia causes the electrical activity of excitable cells in the body to increase.

____ 6. Depolarization causes the electrical activity of excitable cells in the body to increase.

Multiple Choice

____ 7. In the resting state, the electrical polarity inside a cell is negative because:
(a) of the presence of non-diffusing, negatively-charged protein inside the

neuron
(b) of the lower concentration of K+ inside the cell compared to the outside
(c) there is net movement of Cl- into the cell
(d) the Na+/K+-ATP Pumps transport more Na+ out of the cell than K+ into

the cell

____ 8. The resting cell membrane potential in cells is primarily affected by the concentration of.

(a) K+

(b) Cl-

(c) Fe+2

(d) Na+

(e) Ca+2
(ab) serotonin

____ 9. The resting membrane potential has a positive charge on the outside of the cell. The most important contributor of this positive charge is the:
(a) movement of K+ out of the cell
(b) movement of Cl- into the cell
(c) action of the Na+/K+-ATP Pumps
(d) high permeability of Na+ across the membrane
(e) movement of Na+ out of the cell

____10. A decrease in the K+ concentration in the ECF:

(a) causes cells to depolarize

(b) causes cells to hyperpolarize

(c) prevents cells from depolarizing

(d) prevents cells from hyperpolarizing

(e) none of the above

____11. In the resting state, K+ diffuse out of cells because of a(n):

(a) concentration gradient

(b) electrical gradient

(c) both (a) & (b)

(d) none of the above

____12. At the resting membrane potential:
(a) the electrical gradient equals the concentration gradient
(b) the electrical gradient is less than the concentration gradient
(c) the electrical gradient is greater than the concentration gradient
(d) the electrical gradient plus the concentration gradient equals the osmotic

gradient
(e) the transport of K+ out of the cell equals the transport of Na+ into the cell

____13. Which one of the following is correct?
(a) hypokalemia a diffusion of K+ out of the cell a depolarization of

cells
(b) hypokalemia a diffusion of K+ out of the cell a hyperpolarization of cells
(c) hypokalemia a diffusion of K+ out of the cell a depolarization of

cells
(d) hypokalemia a diffusion of K+ out of the cell a hyperpolarization of

cells
(e) hyperkalemia a diffusion of K+ into the cell a depolarization of

cells
(ab) hyperkalemia a diffusion of K+ into of the cell a hyperpolarization of

cells
(ac) hyperkalemia a diffusion of K+ into the cell a hyperpolarization of

cells

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