A&P Lecture: Module 5 Membrane Potential Quiz

Graded potential summation Question options: A) can NOT occur- the potential is All-or-None B) occurs when the effects of a graded potential are added to the effects by a subsequent potential C) needs both sodium and potassium ion gated channels simultaneously opened D) will not occur if the second stimulus is applied before the first stimulus' potential has returned to the resting membrane potential

(not A)

If the extracellular concentration of K+ were decreased, which of the following would occur? Question options: A) hyperpolarization. B) depolarization. C) An initial wave of depolarization followed by a wave of hyperpolarization D) No change would occur, as K+ ions are irrelevant when considering action potentials.

(not B)

If you increased the concentration of extracellular Na+ of a membrane at resting membrane potential, what would happen? Question options: A) hyperpolarization B) depolarization C) hypopolarization D) hardly any change in the membrane potential E) more information is needed.

(not B)

What would lead to hyperpolarization? Question options: A) Increasing plasma membrane permeability to Na+ B) Decreasing plasma membrane permeability to K+ C) Decreasing plasma membrane permeability to Cl- D) Any positive ion moving into the cell E) None of the answers are correct F) Two of the answers are correct

(not B)

The resting membrane potential of a cell is = -60mV, and the intracellular and extracellular Cl- concentrations are [Cl-]inside = 7 mM and [Cl-]outside = 105 mM, respectively. Which of the following statements is FALSE? Question options: A) The Cl- electrical gradient is inward B) The Cl- concentration gradient is inward C) Both a and b are True statements D) Both a and b are False statements

(not D)

_____ has the greatest influence on the resting membrane potential. Question options: A) Sodium B) Chloride C) Calcium D) Phosphate E) Potassium

E) Potassium

As the stimulus strength and size of the graded potential _____________ the action potential frequency ___________. Question options: A) Increases; increases B) Decreases; increases

A) Increases; increases

If a cell membrane became more permeable to Na+ what would happen to the resting membrane potential? Question options: A) Na+ diffuses into the cell causing depolarization. B) Na+ diffuses out of the cell causing depolarization. C) Na+ diffuses out of the cell causing hyperpolarization. D) Na+ diffuses out of the cell causing hyperpolarization.

A) Na+ diffuses into the cell causing depolarization.

The resting membrane potential of a cell is = -60mV, and the intracellular and extracellular Cl- concentrations are [Cl-]inside = 7 mM and [Cl-]outside = 105 mM, respectively. Which of the following statements is FALSE? Question options: A) The Cl- electrical gradient is inward B) The Cl- concentration gradient is inward C) Both a and b are True statements D) Both a and b are False statements

A) The Cl- electrical gradient is inward

Which of the following statements best describes the environment outside a resting cell plasma membrane compared to that within the resting cell plasma membrane? Question options: A) The external environment is positively charged compared to the internal environment. B) Both the external and internal environments are neutral . C) The external environment is negatively charged compared to the internal environment. D) The external environment is negatively charged only if the sodium-potassium pump is functioning.

A) The external environment is positively charged compared to the internal environment.

If extracellular concentration of K+ increases, what will the effect be on the resting membrane potential? Question options: A) The increase in extracellular K+ concentration will decrease the normal K+ gradient; because of this K+ has less of a tendency to diffuse out of the cell. The resting membrane potential becomes less negative (depolarizes). B) The increase in extracellular K+ concentration will increase the normal K+ gradient; because of this K+ has more of a tendency to diffuse out of the cell. The resting membrane potential becomes more negative (hyperpolarizes). C) The increase in extracellular K+ concentration will decrease the normal K+ gradient; because of this K+ has less of a tendency to diffuse out of the cell. The resting membrane potential becomes less negative (hyperpolarizes). D) The increase in extracellular K+ will increase the normal K+ concentration gradient; because of this K+ has more of a tendency to diffuse out of the cell. The resting membrane potential becomes less negative (depolarizes).

A) The increase in extracellular K+ concentration will decrease the normal K+ gradient; because of this K+ has less of a tendency to diffuse out of the cell. The resting membrane potential becomes less negative (depolarizes).

Cells electrical properties are caused by __________? Question options: A) differences in ion concentration across the plasma membrane. B) the many different receptors present on the plasma membrane. C) phosphorylation in the cells cytoplasm. D) phospholipids in the bilayer. E) none of the above.

A) differences in ion concentration across the plasma membrane.

Which of the following is NOT a characteristic of a graded potential? Question options: A) the size of the graded potential is inversely proportional to the strength of the stimulus B) are conducted so that the magnitude decreases as they are spread over the plasma membrane C) a depolarizing potential can cause an action potential D) can cause depolarization or hyperpolarization dependent upon which ion has increased permeability

A) the size of the graded potential is inversely proportional to the strength of the stimulus

Which of the following would cause the resting membrane potential of a neuron to move from: -85mv to -50mv? 1 - Increased permeability to K+ 2 - Increased permeability to Na+ 3 - Increased concentration of Na+ in the extracellular fluid 4 - Increased activity of the Na+/K+ pump Question options: A) 1 B) 2 C) 1,2 D) 2,4 E) 1,3 F) 1,4 G) 1,2,3,4

B) 2 2 - Increased permeability to Na+

If the plasma membrane becomes more permeable to K+, what effect will it have on the resting membrane potential? Question options: A) Because the membrane is more permeable to K+, less K+ will diffuse out of the cell. The inside of the cell becomes less negative resulting in depolarization. B) Because the membrane is more permeable to K+, more K+ will diffuse out of the cell. The inside of the cell becomes more negative resulting in hyperpolarization. C) Because the membrane is more permeable to K+, less K+ will diffuse out of the cell. The inside of the cell becomes less negative and results in hyperpolarization. D) Because the membrane is more permeable to K+, more K+ will diffuse out of the cell. The inside of the cell becomes less negative and results in depolarization.

B) Because the membrane is more permeable to K+, more K+ will diffuse out of the cell. The inside of the cell becomes more negative resulting in hyperpolarization.

Which of the following is TRUE regarding the generation of a membrane potential? Question options: A) Potassium, Calcium and Sodium ions can "leak" through a resting cell membrane as these ions move down a concentration gradient. B) The maintenance of the Resting Membrane Potential (RMP) depends on ion concentration gradients and electrical gradients. C) In the depolarized state, enough K+ leaves and enough Na+ enters that these ion concentrations are equal on both sides of the membrane D) When the sodium potassium pump is activated, potassium is pumped into the cell twice as fast as the sodium is pumped out, thus causing the membrane potential. E) All of the above are TRUE

B) The maintenance of the Resting Membrane Potential (RMP) depends on ion concentration gradients and electrical gradients.

Which statement(s) are correct? I-all membranes parts have their own unique, fixed position. II-The plasma membrane of muscle cells is ALWAYS permeable to glucose. III-The phospholipid bilayer is made up of approximately 85% lipid. IV-Receptor proteins must be a type of peripheral or extrinsic proteins. V-Epinephrine is a type of receptor in a cell membrane VI-Simple diffusion is based on the fact that molecules are in constant, random motion. Because of collisions with each other, and anything else in the particles way, they eventually disperse- or are evenly distributed throughout the system. Question options: A) I, IV, V B) VI C) I, II, III D) III, IV E) II F) All of the above

B) VI VI-Simple diffusion is based on the fact that molecules are in constant, random motion. Because of collisions with each other, and anything else in the particles way, they eventually disperse- or are evenly distributed throughout the system.

If the extra cellular fluid around a muscle cell is replaced with an isotonic saline solution that contains less K+ than the normal extra cellular fluid, the result would be: Question options: A) a nonexistent resting membrane potential B) a hyperpolarized membrane C) a depolarized membrane D) a resting membrane potential at normal values

B) a hyperpolarized membrane

If you decreased concentration of K+ OUTSIDE (hypokalemia) of a resting membrane, you would induce: Question options: A) depolarization B) hyperpolarization C) absolute refraction D) repolarization

B) hyperpolarization

If a plasma membrane becomes more permeable to K+ the charge difference across the plasma membrane will _________, or (AKA) _________. Question options: A) increase, depolarize B) increase, hyperpolarize C) decrease, depolarize D) decrease, hyperpolarize

B) increase, hyperpolarize

The plasma membrane of a cell is more permeable to K+ because ________ Question options: A) of its positive charge. B) more non-gated channels exist for K+ than for Na+. C) negatively charged protein molecules cannot exit through the cell membrane. D) more gated channels exist for K+

B) more non-gated channels exist for K+ than for Na+.

During resting membrane potential, the charge inside of a cell is _____ compared to the outside of the cell. Question options: A) positive B) negative C) neutral D) oscillating

B) negative

Concerning resting membrane potential, the inside of the membrane is _______ compared to the ________ charged outside. Question options: A) positive, negatively B) negative, positively. C) Neutral, cyclically D) AC (alternating current)

B) negative, positively.

When the voltage of a plasma membrane changes from +30mV towards -5 mV, we say the cell is _______. Question options: A) depolarizing B) repolarizing C) hyperpolarizing D) hitting threshold

B) repolarizing

In some cells, an afterpotential (hyperpolarization) occurs, because ________. Question options: A) the sodium ions continue to enter the cell after depolarization is finished. B) there is prolonged, elevated permeability to potassium during repolarization. C) the sodium-potassium pump is actively exchanging ions across the membrane. D) the extracellular Na+ ion concentration is reduced. E) the permeability to sodium continues longer than necessary.

B) there is prolonged, elevated permeability to potassium during repolarization.

You are observing a simple diffusion experiment of green food coloring being carefully added to the surface of two containers holding an equal volume of water, one at 0 degrees C and the other at 100 degrees C. Your original hypothesis is that because the food coloring is being added to the surface, it will be traveling down the concentration gradient in both cases. Therefore diffusion in both systems will be complete at the same time. Is your hypothesis correct or incorrect? Question options: A) Correct, all substances naturally travel down their concentration gradients. B) Incorrect, all substances naturally travel up their concentration gradients. C) Incorrect, because of the increased speed and motion of the water particles in the 100 degree system it will finish diffusion much faster than the 0 degree system. D) Correct, because there is an equal volume of water in each system it will take the same amount of time for diffusion to complete (time to diffuse is proportional to the square of the distance).

C) Incorrect, because of the increased speed and motion of the water particles in the 100 degree system it will finish diffusion much faster than the 0 degree system.

Which of the following is true concerning leak channels? Question options: A) They respond to changes in voltage across a membrane. B) They respond to a ligand binding to its receptor protein. C) They cause ion permeability in a resting membrane. D) None of the above.

C) They cause ion permeability in a resting membrane.

The flu virus increases cellular membrane permeability to K+. You would expect the cells of someone suffering from the flu to _______. Question options: A) repolarize B) depolarize C) hyperpolarize D) more information is needed.

C) hyperpolarize

At resting membrane potential, what will cause the plasma membrane to hyperpolarize? Question options: A) Na+ flowing into the cell B) K+ flowing into the cell C) Ca++ flowing into the cell D) Cl- flowing into the cell E) Cl- flowing out of the cell

D) Cl- flowing into the cell

Which of the following statements is correct regarding Na+ and K+ concentrations across a plasma membrane? Question options: A) Concentrations of both K+ and Na+ ions are higher outside of a cell than they are on the inside of a cell. B) Concentrations of both K+ and Na+ are higher inside of a cell than they are outside of a cell. C) Concentrations of K+ are higher outside of a cell, whereas concentrations of Na+ are higher inside of a cell. D) Concentrations of Na+ are higher outside of a cell, whereas concentrations of K+ are higher inside of a cell.

D) Concentrations of Na+ are higher outside of a cell, whereas concentrations of K+ are higher inside of a cell.

Which ion has greatest influence on resting membrane potential? Question options: A) Na+ B) Cl- C) Ca++ D) K+

D) K+

If you increased the concentration of extracellular Na+ of a membrane at resting membrane potential, what would happen? Question options: A) hyperpolarization B) depolarization C) hypopolarization D) hardly any change in the membrane potential E) more information is needed.

D) hardly any change in the membrane potential

The resting membrane potential Question options: A) is positive B) is a result of ligand-gated channels C) is more negatively charged on the outside versus the inside of the cell D) is contributed by the many potassium leak ion channels which move the ion out of the cell E) all of the above

D) is contributed by the many potassium leak ion channels which move the ion out of the cell