Quiz Physiology

Physiology 14Mar2009

DO NOT DISTRIBUTE - 1 -

1 – Cellular Membranes and Transmembrane Transport of Solutes and Water

1.1) Which of the following is NOT a function of cellular membranes?

a) Divide the cell into discrete compartments

b) Membrane proteins are involved in transducing signals from the cell to its

surroundings

c) Allow for the intra- and extra-cellular fluid compositions to remain constant

and equal

d) Contains enzymes, receptors, and antigens that play central roles in the

interaction of regulatory agents in the extracellular fluid

e) Allow the localization of particular biochemical processes in specific

organelles

1.2) A patient is undergoing a gastrointestinal x-ray with barium contrast. Barium ions in

the drink ingested by the patient are highly toxic, but these ions are not absorbed because:

a) Barium is insoluble in the hydrophobic exterior of the cell

b) Barium is insoluble in the hydrophobic membrane interior

c) Barium is insoluble in the hydrophobic interior of the cell

d) Barium is soluble in the hydrophilic exterior of the cell

e) Barium is soluble in the hydrophilic membrane interior

2) Which of the following is NOT true regarding the fluid-mosaic model?

a) Phospholipid or protein "flip-flop" occurs infrequently

b) Many of the constituent molecules are free to diffuse in the plane of the

membrane

c) Most lipids and proteins can move freely in the bilayer plane

d) The model is consistent with many of the properties of biological membranes

but is not an absolute fact

e) A large hydrophilic moiety is the most likely to flip-flop

3) Integral membrane proteins are embedded in the phospholipid bilayer and peripheral

proteins are associated with the surface of the membrane. Which of the following best

describes how peripheral proteins interact with the membrane?

a) By charge interactions with integral membrane proteins

b) By charge interactions with integral membrane lipids

c) By binding with integral membrane proteins

d) By binding with integral membrane lipids

e) By binding throughout the phospholipid bilayer

4) What are the two most prevalent phospholipid classes in membranes?

a) Lecithins (phosphatidylcholines) and the sphingomyelins

b) Phosphatidylserine and phosphatidylethanolamine

c) Glycerol and amino

d) Choline and amino

e) Alcohol and carbohydrate

5.1) Which membrane component buffers the fluidity of the membrane in the presence of

agents that tend to fluidize biological membranes, such as general anesthetics?

a) Glycoproteins

b) Glycolipids

c) Cholesterol

d) Carbohydrates



e) Phospholipids

5.2) The receptor for cholera toxin and the receptor for A and B blood group antigens are

carbohydrate moieties. These moieties protrude from the external surface of the

membrane and are part of what non-abundant membrane component?

a) Alcohol

b) Glycolipids

c) Glycopeptides

d) Glycoproteins

e) Glycosamines

6) Phospholipids are distributed asymmetrically (and variably) between the inner and

outer lipid monolayer of the membrane. Which of the following groups is found almost

exclusively in the outer monolayer?

a) Proteins

b) Glycolipids

c) Glycopeptides

d) Glycoproteins

e) Glycosamines

7) Which of the following best describes why membranes "pose a formidable barrier" to

most biologically active compounds?

a) Membranes are highly permeable to water-soluble substances

b) Steroids bound to lipids and other nonpolar compounds are blocked from

entering the cell by glycoproteins

c) Biologically active compounds are soluble in the interior of the lipid bilayer

d) Most molecules present in living systems are soluble in nonpolar solvents

e) Most molecules present in living systems are soluble in water

8.1) Clathrin coated pits are involved in which of the following processes?

a) Receptor-mediated endocytosis

b) Non-metabolic endocytosis

c) Phagocytosis

d) Pinocytosis

e) Exocytosis

8.2) Which of the following would be a way for water-soluble (polar) molecules to enter

the cell?

a) Receptor-mediated endocytosis

b) Non-metabolic endocytosis

c) Phagocytosis

d) Pinocytosis

e) Exocytosis

8.3) Influenza viruses have membrane proteins that undergo a dramatic conformational

change to insert a "fusion peptide" into the host cell. The fusion peptide promotes the

fusion of the viral membrane with the plasma membrane of the host cell. What is the

most likely result of this process?

a) The virus and host cell will form a new, larger host cell

b) The host cell will lyse upon fusion

c) The viral genome will enter the host cell

d) The host cell contents will transfer to the virus



e) The virus and host cell will form a barrier against each other

9.1) Which of the following best describes Brownian motion (diffusion)?

a) The process whereby atoms or molecules move because of their constant

thermal motion

b) The process whereby atoms or molecules move because of their random

thermal motion

c) The process whereby atoms or molecules move because of their constant

kinetic motion

d) The process whereby atoms or molecules move because of their random kinetic

motion

e) The process whereby atoms or molecules move because of their potential

motion

9.2) Imagine a container divided into two compartments by a removable barrier. A much

larger number of molecules of a compound are placed on side A than on side B, and then

the partition is removed. Which of the following statements about diffusion is true?

a) Movement will occur only from side A to side B

b) The rate of diffusion will initially be faster from side B

c) The rate of diffusion will initially be slower from side A

d) When the number of molecules on side A and side B are the same, no more

movement (diffusion) will occur

e) When the number of molecules on side A and side B are the same, the rate of

diffusion will be the same on both sides

10) A typical molecule takes 1-msec to diffuse 1-µm. If diffusion distance is increased by

10-fold, how much longer will the diffusion process need to achieve a given level of

completion?

a) 5 times longer

b) 10 times longer

c) 20 times longer

d) 100 times longer

e) 1000 times longer

11) Which of the following would give the smallest diffusion coefficient of a molecule in

fluid?

a) Large molecule and viscous medium

b) Small molecule and viscous medium

c) Large molecule and non-viscous (thin) medium

d) Small molecule and non-viscous (thin) medium

12) Which of the following is true regarding Fick's first law of diffusion?

a) Membrane area and membrane thickness are directly proportional to flux (J),

while membrane concentration difference is inversely proportional

b) Membrane area and membrane concentration difference are directly

proportional to flux (J), while membrane thickness is inversely proportional

c) Membrane area is directly proportional to flux (J), while membrane

concentration difference and membrane thickness are inversely proportional

d) Membrane area, membrane concentration difference, and membrane thickness

are directly proportional to flux (J)



e) Membrane area, membrane concentration difference, and membrane thickness

are inversely proportional to flux (J)

13.1) The permeability of membranes to a particular molecule is:

a) Inversely proportional to its solubility on the exterior of the lipid bilayer

b) Inversely proportional to its solubility in the interior of the lipid bilayer

c) Proportional to its solubility on the exterior of the lipid bilayer

d) Proportional to its solubility in the interior of the lipid bilayer

e) Is not related to solubility of the lipid bilayer

13.2) Plasma membranes of many cells contain membrane proteins called aquaporins that

form channels permitting a high rate of water flow across the membrane; higher than

their predicted lipid solubility. If the water channels that pull in water from the kidney

nephrons were defective, what would be the most likely result?

a) No urine output

b) Concentrated urine

c) Non-concentrated urine

d) Inability of lipid-soluble vitamins to cross the membrane

e) Inability of lipid-soluble hormones to cross the membrane

13.3) The permeability of membranes to uncharged, water-soluble molecules ____ as the

size of the molecules ____.

a) Does not change; Changes

b) Increases; Increases

c) Decreases; Decreases

d) Increases; Decreases

e) Decreases; Increase

14.1) Two chambers are separated by a semi-permeable membrane. Chamber A contains

a solute (NaCl) and chamber B contains only water. Pressure is measured in chamber A

as a hydrostatic force is applied to chamber A in the direction of chamber B. Which of

the following could find the osmotic pressure of this system?

a) At 100mMol NaCl, all water moves into chamber A

b) At 127mMol NaCl, water slowly moves into chamber A

c) At 154mMol NaCl, there is no net movement

d) At 181mMol NaCl, water slowly moves into chamber B

e) At 200mMol NaCl, all water moves into chamber B

14.2) The osmotic coefficient (!) accounts for the deviation of the solution from the

ideal. The value of ! is less than 1 for electrolytes of physiological importance and for all

solutes ! approaches 1 as the solution becomes more:

a) Concentrated

b) Dilute

c) Polarized

d) Unpolarized

e) Depolarized

14.3) Osmotic pressure depends primarily on the chemical properties of the solute

present, rather than the colligative properties.

a) True

b) False



14.4) the osmotic pressure of a solution can be estimated from its freezing point.

a) True

b) False

15.1) At 154 mM NaCl (isotonic), the red cell has a normal volume. If a red blood cell is

put into a 170 mM NaCl solution, the cell will:

a) Remain the same

b) Burst

c) Swell

d) Shrink

e) Dissolve

15.2) A trauma patient presents to the Emergency Department. You setup an intravenous

(IV) line and begin infusing isotonic 0.9% normal saline (0.9NS). As the saline combines

with the blood cells closest to the IV site, the cells will:

a) Dissolve

b) Shrink

c) Swell

d) Burst

e) Remain the same

15.3) Physiologic osmotic pressure is about:

a) 124 milliosmolar

b) 212 milliosmolar

c) 286 milliosmolar

d) 368 milliosmolar

e) 488 milliosmolar

16) Which of the following describes what makes active transport different from

facilitated transport?

a) Moves a substance down its chemical gradient

b) Moves a substance down an electrochemical gradient

c) Pumps a substance with a chemical gradient

d) Pumps a substance with an electrochemical gradient

e) Requires energy

17.1) Movement via a transport protein showing saturation kinetics will reach Km of the

transported substance at what rate of transport?

a) Maximal rate of transport

b) Half maximal rate of transport

c) Quarter maximal rate of transport

d) Initial rate of transport

e) No transport rate change occurs at this point

17.2) Which of the following states that only molecules with the requisite chemical

structure are transported?

a) Chemical formula

b) Saturation kinetics

c) Chemical specificity

d) Competitive inhibition

e) Noncompetitive inhibition



17.3) If one transport substrate decreases the transport rate of a second substrate by

fighting for binding to the transporter, this is called:

a) Chemical formula

b) Saturation kinetics

c) Chemical specificity

d) Competitive inhibition

e) Noncompetitive inhibition

18.1) The Na+/K+ ATPase pump, which works against a gradient and uses ATP as

energy, is an example of:

a) Competitive inhibition

b) Noncompetitive inhibition

c) Facilitated transport

d) Primary active transport

e) Secondary active transport

18.2) Amino acids getting their energy indirectly from the gradient of Na+ that is itself

undergoing transport (against a gradient), is an example of:

a) Competitive inhibition

b) Noncompetitive inhibition

c) Facilitated transport

d) Primary active transport

e) Secondary active transport

19.1) What class of membrane transport proteins includes Glucose, usually has multiple

!-helices, and involves binding of the substrate from one side, a conformational change

of the protein, then release of the substrate to other side of membrane?

a) Pores

b) Channels

c) Transporters (carriers)

19.2) What class of membrane transport proteins has a very low rate of diffusion through

a closed channel and where accessibility depends on the location of the gated structure?

a) Pores

b) Channels


19.3) What class of membrane transport proteins has a permeation pathway that is

accessible from both sides of the membrane at all times?

a) Pores

b) Channels


20) Epithelial cells are considered polarized due to different ____ sitting on opposite

sides of the membrane (apical versus basolateral plasma membrane).

a) Phospholipids

b) Peripheral proteins

c) Integral proteins

d) Transport proteins

e) Membrane proteins



2 – Ionic Equilibria and Resting Membrane Potentials

1.1) The force of diffusion (Fd) acts on all particles. In the equation to calculate Fd, the

concentration of a particular species (C) is ____ related and the changing variable (d/dx),

with respect to distance, is ____.

a) Directly; Concentration gradient

b) Reciprocally; Concentration gradient

c) Directly; Voltage across the membrane

d) Reciprocally; Voltage across the membrane

1.2) The force due to the electrical gradient (Fe) applies to ions. In the equation to

calculate Fe, the valence (z) of the ion is ____ related and the changing variable, (d/dx)

with respect to distance, is ____.

a) Directly; Concentration gradient

b) Reciprocally; Concentration gradient

c) Directly; Voltage across the membrane

d) Reciprocally; Voltage across the membrane

1.3) Net force is defined as Fe + Fd, where Fe is “electro-“ and Fd is “-chemical”. For an

ion to passively cross a membrane, Fnet must be at equilibrium and the membrane must

be permeable to the particle. At equilibrium, the net force acting on an ion is:

a) Increasing

b) Constant

c) Decreasing

d) Zero

e) Infinite

2.1) Which of the following must be true for a membrane to be permeable?

a) Permeability coefficient < 0

b) Permeability coefficient = 0

c) Permeability coefficient > 0

2.2) Conductivity is ____ related to resistance and ____ proportional to permeability as

permeability also includes uncharged particles.

a) Directly; Directly

b) Reciprocally; Directly

c) Directly; Inversely

d) Reciprocally; Inversely

3.1) In a normal semi-permeable lipid membrane, Na+ (outside) is ____ and K+ (inside)

is ____ to the membrane.

a) Impermeable; Permeable

b) Permeable; Impermeable

c) Impermeable; Impermeable

d) Permeable; Permeable

3.2) To have a positive current (by the current equation), we would need the flux of K+ to

be ____ and the flux of Na+ to be ____.

a) Positive; Positive

b) Negative; Negative

c) Zero; Zero

d) Negative; Positive

e) Positive; Zero



3.3) As a negative membrane voltage (Vm) is established, an Fe will be generated for

each ion in solution. For K+, the direction of Fe will be ____ Fd. As K+ fluxes outward,

Vm increases and Fe will be equal to Fd in magnitude. At this point, Fnet will be ____.

a) Opposite that of; Double

b) Opposite that of; Zero

c) The same as; Double

d) The same as; Zero

3.4) A stable Vm will develop (steady resting membrane potential, Vr) when Fnet is ____

for all permeable ions and "net, or flux, is ____. At this point, we have a Donnan-

equilibrium.

a) Negative; Zero

b) Positive; Zero

c) Zero; Zero

d) Negative; Positive

e) Positive; Negative

4.1) If the Nernst equation calculated Vr to be -95mV for a living neuron or muscle cell,

the force due to the electrical gradient (Fe) is ____ the force due to diffusion (Fd), in

magnitude.

a) Greater than

b) Less than

c) Equal to

4.2) For all permeable ions, the Nernst equilibrium potential for an ion (Ei) is equal to:

a) Net force acting upon an ion (Fnet)

b) Net force due to friction (Ffr)

c) Force for diffusion (Fd)

d) Force due to the electrical gradient (Fe)

e) Fd and Fe

5.1) To determine if an ion is in equilibrium at a measured membrane potential, the

Nernst equation must be calculated. This requires measuring:

a) Ion concentrations inside and outside of the cell

b) Ion concentration inside of the cell

c) Ion concentration outside of the cell

d) Flux moving from inside of the cell

e) Flux moving from outside of the cell

Match the following ions their Nernst potentials (Ei):

5.2) Magnesium a) -109mV

5.3) Calcium b) -36mV

5.4) Chloride c) -92mV

5.5) Sodium d) +68mV

5.6) Potassium e) +120mV

6) Which two variables must be equivalent for an ion to be at equilibrium?

a) Ion concentrations inside and outside of the cell

b) Flux and Nernst potential

c) Flux and Membrane potential

d) Membrane potential and Nernst potential

e) Membrane potential and Ion valence



7) Which of the following is NOT needed for a system to be at a Donnan-equilibrium?

a) "net = 0 and Fnet = 0 for all permeable ions

b) Vr exists (Inet = 0)

c) Ei = Vr for all permeable ionic species

d) All ions are in steady-state at Vr

e) Vr maintenance requires energy

8) Which of the following helps explain why cells do NOT obey a Donnan-equilibrium?

a) The measured Nernst Vr for a muscle cell versus the calculated value

b) The permeable behavior of K+

c) The permeable behavior of Na+

d) The permeable behavior of Cl-

e) The lack of energy expenditure to maintain Vr

9) Which of the following is in agreement between the Donnan-equilibrium concept and

the non-equilibrium steady-state (NESS) concept?

a) Fnet of all permeable ions is zero

b) "net = 0 for all permeable ions

c) Vr=Ei for all permeable ions

d) Expenditure of energy is required to maintain Vr

10.1) The Na/K ATPase pump is essential in maintaining ionic concentrations and moves

Na+ and K+ unequally across the membrane. It actively transports ____ Na+ out of the

cell for every ____ K+ transported into the cell.

a) 1; 2

b) 2; 1

c) 2; 2

d) 2; 3

e) 3; 2

10.2) Some pharmacological agents, such as cardiac glycosides (digitalis, ouabain), work

by inhibiting the Na/K ATPase. This would ____ its rate of activity and ____ Vr.

a) Decrease; Decrease

b) Increase; Increase

c) Decrease; Increase

d) Increase; Decrease

11) Which of the following best describes the chord conduction equation?

a) Membrane potential is the sum of the equilibrium potentials of the membrane-

permeable ions

b) Membrane potential is the sum of the equilibrium potentials of all ions

c) Membrane potential is the weighted average of the equilibrium potentials of the

membrane-permeable ions

d) Membrane potential is the weighted average of the equilibrium potentials all

ions

e) Membrane potential is the reciprocal of the equilibrium potentials of the

membrane-permeable ions

12) Referring to the chord conductance equation. If gCl- = gNa+ = gMg++ = gCa++ = 0,

but gK+ is significant, then what is Em?

a) -109mV

b) -36mV



c) -92mV

d) +68mV

e) +120mV

3 – Generation and Conduction of Action Potentials

1) For a non-gated (leakage) and regulated (gated) channels, what depends on the size of

the channel and the characteristics of the channel protein?

a) Fd (force of diffusion)

b) Fe (force due to electrical gradient)

c) Vr (Nernst potential)

d) Vm (Membrane potential)

e) g (conductance)

2) For non-gated (leakage) channels, Na+, Cl-, and K+ channels are responsible for

determining:

a) Conductance

b) Resistance

c) The resting cell potential

d) The maximal cell potential

e) Net force

3.1) Blood vessels have channels that open in response to physical stress, like stretching.

What type of channels are these?

a) Chemical/Receptor-gated

b) Mechanical-gated

c) Light-gated

d) Voltage-gated

3.2) Some hormones contain a region near the channel protein with a ligand-bindable

receptor. These gates will only open after a certain number of bindings have taken place

and the probability of opening is high. What type of channels are these?


b) Mechanical-gated

c) Light-gated

d) Voltage-gated

3.3) At rest, a gate is open. As the membrane potential changes enough to reach a specific

point, these gates close. This is a specific type of what kind of channel?


b) Mechanical-gated

c) Light-gated

d) Voltage-gated

4) A single channel can change its state more than once in response to a single stimuli.

The mean time that the channel remains open (or closed), topen, is a characteristic

property of:

a) Chemical/Receptor-gated channels

b) Mechanical-gated channels

c) Light-gated channels

d) Voltage-gated channels

e) Each channel type



5.1) In the voltage-clamping technique, ____ is injected into a cell and the membrane

potential is clamped at ____ voltage.

a) Current; Zero

b) Voltage; Zero

c) Current; A specific

d) Voltage; A specific

e) Current; Original membrane

5.2) The patch-clamp technique improved on the voltage-clamping technique by allowing

for measurements across ____ ion channels. This is done by plucking a small piece of

membrane with the tip of a micropipette, where the inside of the pipette contains the ____

fluid.

a) Single; Intracellular

b) Multiple; Intracellular

c) Single; Extracellular

d) Multiple; Extracellular

6.1) In a typical voltage-gated sodium channel, there are ____ m-gates and ____ h-gates

from extracellular moving to intracellular.

a) 3; 1

b) 1; 3

c) 2; 1

d) 1; 2

e) 3; 3

6.2) In a typical voltage-gated potassium channel, there are ____ n-gates and ____ h-

gates from extracellular moving to intracellular.

a) 4; 1

b) 1; 4

c) 4; 0

d) 0; 4

e) 4; 4

7.1) For sodium channels, the m-gates are responsible for quickly ____ as the channel

membrane depolarizes and the h-gates are responsible for quickly ____ upon

depolarization.

a) Opening; Opening

b) Closing; Closing

c) Opening; Closing

d) Closing; Opening

7.2) For potassium channels, current is ____ lasting than sodium channels and terminates

after ____, when Vm is made more negative.

a) Shorter; Depolarization

b) Longer; Depolarization

c) Shorter; Repolarization

d) Longer; Repolarization

8.1) For sodium channels, if Vr = -90 and the cell is depolarized by 20mV (to -70mV),

the probability that each m-gate is open is Pm. The probability that each h-gate is open is

Ph. What is the probability that a channel will open, Po?

a) Po = Pm + Ph



b) Po = Pm * Ph

c) Po = 3Pm + Ph

d) Po = 3Pm * Ph

e) Po = Pm^3 * Ph

8.2) For potassium channels, if Vr = -90 and the cell is depolarized by 20mV (to -70mV),

the probability that each n-gate is open is Pn. What is the probability that a channel will

open, Po?

a) Po = Pn

b) Po = 4Pn

c) Po = Pn + Pn + Pn + Pn

d) Po = Pn * Pn

e) Po = Pn^4

9) The voltage response of the membrane during a small, sustained current injection

(electrotonic response) is best described as:

a) Substantial

b) Transient

c) Stepwise

d) Constantly decreasing

e) Constantly increasing

10) What account for the additional depolarization during local response?

a) Electrical characteristics of the membrane

b) Potassium channels

c) Sodium channels

d) ATPase

e) Electrical transients

11) When current is injected into a membrane and the threshold potential is exceeded,

depolarization is:

a) Transient

b) 10-20mV

c) 10-20mV greater than Vr

d) Proportional to the injected current

e) Maximal/Complete

12) During an action potential, when threshold is reached many ____ gates open and

rapid depolarization occurs. At the peak of the action potential, many ____ gates open as

the original gates close and rapid repolarization occurs. In depolarization and

repolarizaton, the Nernst potentials (E) for both ions are ____.

a) Sodium; Potassium; Reached

b) Potassium; Sodium; Not reached

c) Sodium; Potassium; Not reached

d) Potassium; Sodium; Reached

13.1) Which of the following is the sequence of events in the positive feedback loop for

sodium channels?

a) Vm depolarizes to threshold, Na+ conductance increases, m-gates open,

sodium channels open, Vm depolarizes

b) Vm depolarizes to threshold, sodium channels open, m-gates open,, Na+

conductance increases, Vm depolarizes



c) Vm depolarizes to threshold, m-gates open, sodium channels open, Na+

conductance increases, Vm depolarizes

d) Vm depolarizes to threshold, Na+ conductance increases, sodium channels

open, m-gates open, Vm depolarizes

e) Vm depolarizes to threshold, m-gates open, Na+ conductance increases,

sodium channels open, Vm depolarizes

13.2) When the cell is depolarized by 60mV, h = 0 (h-gate closed). The cell can

depolarize by more than 60mV because in sodium channels the ____ gate(s) is/are slower

than the ____ gate(s) to changes in Vm. The sodium channel is considered “re-set” when

the ____ gate(s) return to resting value.

a) M; H; H

b) H; M; M

c) M; H; M

d) H; M; H

13.3) For potassium channels, the peak of the action potential has Po = 50% and not the

expected 100% (approximately). This is because n-gates are ____ and ____ occurs before

the channels have time to reach the Po = 99% value.

a) Fast; Repolarization

b) Slow; Repolarization

c) Fast; Depolarization

d) Slow; Depolarization

13.4) As the cell depolarizes, the electrochemical gradient for sodium ____ at a rate that

is ____ than gNa+ increases.

a) Decreases; Faster

b) Increases; Faster

c) Decreases; Slower

d) Increases; Slower

13.5) As the cell repolarizes, the electrochemical gradient for sodium ____ at a rate that

is ____ than gNa+ decreases.

a) Decreases; Faster

b) Increases; Faster

c) Decreases; Slower

d) Increases; Slower

13.6) Chloride leakage channels ____ the process of depolarization (sodium influx) and

____ the process of repolarization (potassium efflux).

a) Speed up; Slow down

b) Slow down; Speed up

c) Speed up; Speed up

d) Slow down; Slow down

14) At the peak of the action potential, approximately ____ of all the voltage-sensitive

sodium channels are open; this being the maximum possible conductance for Na+.

a) 100%

b) 80%

c) 60%

d) 40%

e) 20%



15) As membrane conductance for a given ion ____, membrane potential will move

toward equilibrium for ____.

a) Increases; That ion

b) Decreases; All ions (equilibrium)

c) Increases; That ion

d) Decreases; All ions (equilibrium)

16) During depolarization, sodium within the cell and potassium outside of the cell is

____. Chlorine concentration is greatest during ____.

a) High; Depolarization

b) Low; Depolarization

c) High; Repolarization

d) Low; Repolarization

17.1) At what point could one determine that the gates and channels have completely

reset to “resting” conditions when comparing to an initial action potential?

a) A stimulus generates no second action potential

b) A small stimulus generates a stunned second action potential

c) A very large stimulus generates a stunned second action potential

d) A stimulus generates a second action potential equal to the first

17.2) Which of the following would occur during the absolute refractory period?

a) A stimulus generates no second action potential

b) A small stimulus generates a stunned second action potential

c) A very large stimulus generates a stunned second action potential

d) A stimulus generates a second action potential equal to the first

17.3) During the relative refractory period, a second action potential can be generated if:

a) The stimulus is much less than the original stimulus

b) The stimulus is equal to the original stimulus

c) The stimulus is much greater than the original stimulus

d) A very short period of time has elapsed

e) No time has elapsed

17.4) The absolute refractory period is a result of inadequate time for resetting of the

____ gates and the relative refractory period is a result of incomplete reactivation of the

____ gates.

a) H; N

b) N; H

c) H; H

d) N; N

e) H; H & N

4 – Synaptic Transmission and Maintenance of Nerve Function

1) Cajal’s “neuron doctrine” proposed that each nerve cell communicates through

“contiguity rather than continuity.” This implies that neurons are:

a) Touching

b) Overlapping

c) Crossed perpendicularly

d) Parallel

e) In close proximity



2.1) Synthesizing enzymes for neurotransmitters that enter the synaptic cleft are

originally formed in the:

a) Axon terminal

b) Axon hillock

c) Soma

d) Myelinated axons

e) Dendrites

2.2) Which of the following areas of the neuron contains tubulin?

a) Soma

b) Axon

c) Dendrite

d) All of the above

2.3) Which of the following areas can contain myelin?

a) Axon

b) Axon terminal

c) Dendrites

d) Nodes of Ranvier

e) A, B, and C

2.4) Where does generation of action potentials begin?

a) Axon terminal

b) Axon hillock

c) Soma

d) Myelinated axons

e) Dendrites

2.5) Where are the active zones located?

a) Axon terminal

b) Axon hillock

c) Soma

d) Myelinated axons

e) Dendrites

3.1) Myelin is formed by ____ in the central nervous system and ____ in the peripheral

nervous system.

a) Schwann cells; Astrocytes

b) Oligodendrocytes; Satellite cells

c) Astrocytes; Schwann cells

d) Satellite cells; Astrocytes

e) Oligodendrocytes; Schwann cells

3.2) Where are voltage gated ion channels most abundant?

a) Myelenated axon

b) Axon terminal

c) Dendrites

d) Nodes of Ranvier

e) Synaptic cleft

3.3) Analogously, myelin sheaths act electrically as high ____ and low ____ insulators.

a) Resistance; Inductance

b) Inductance; Capacitance



c) Capacitance; Resistance

d) Resistance; Capacitance

e) Inductance; Resistance

4) What protein is associated with electrical synapses?

a) Cadherin

b) Alpha-actinin

c) Connexin

d) Clathrin

e) Calcium

5.1) What part of the synaptic junction contains acetylcholine esterase?

a) Synaptic vesicles

b) Active zones

c) Alpha-motor-neurons

d) End-plate peaks

e) End-plate troughs

5.2) In the neuromuscular junction, depolarization of the axon terminus leads to:

a) ACh diffusion of 30nm

b) Binding of ACh

c) Opening of chemical-sensitive channels

d) Opening of Ca++ channels

e) Depolarization of the adjacent neuron

5.3) Postsynaptic receptor binding of ACh opens chemical-sensitive ____ channels,

which have an associated ____ in sodium and potassium conductance.

a) Cation; Increase

b) Anion; Increase

c) Cation; Decrease

d) Anion; Decrease

6.1) Which of the following is observed at rest at around 0.5mV?

a) EPSP

b) IPSP

c) MEPP

6.2) Which of the following does NOT happen at the neuromuscular junction?

a) EPSP

b) IPSP

c) MEPP

7) Which of the following can summate to depolarize the postsynaptic muscle cell and

create an action potential?

a) EPSP

b) IPSP

c) MEPP

8.1) Temporal summation involves firing of ____ presynaptic neuron(s), generating a

series of EPSP’s on the postsynaptic cell. Spatial summation involves firing of ____

presynaptic neuron(s), generating multiple EPSP’s on the postsynaptic cell.

a) One; Multiple

b) Two; Multiple

c) Three; One



d) Multiple; One

e) Multiple; Two

8.2) EPSP’s decay ____, which is caused by the closure of chemically gated ____

channels.

a) Slowly; Potassium

b) Quickly; Potassium

c) Slowly; Sodium

d) Quickly; Sodium

9) An action potential generated at the axon hillock occurs as a proportional response,

rather than a binary response.

a) True

b) False

10) The length constant is defined as the point, between nodes of Ranvier, where what

percentage of the signal is remaining?

a) 100%

b) 63%

c) 50%

d) 37%

e) 0%

11) Regenerative conduction occurs ____ and passive (electronic) conduction occurs

____.

a) Between nodes of Ranvier; Along the entire axon

b) Along the entire axon; Between nodes of Ranvier

c) Between nodes of Ranvier; Between nodes of Ranvier

d) Along the entire axon; Along the entire axon

12.1) The calcium channel essential for neurotransmitter release is a ____ activating

channel responsible for the ____ calcium current.

a) Fast; Inward

b) Slow; Inward

c) Fast; Outward

d) Slow; Outward

12.2) The calcium channel has ____ activation (d-) gate(s) and ____ inactivation (f-)

gate(s).

a) 1; 1

b) 2; 2

c) 1; 2

d) 2; 1

e) 1; 3

13.1) Once calcium enters the cell, it appears to sever the ____ links, which are meant to

hold the vesicle stationary.

a) Tubulin

b) Myosin

c) Actin

d) Connexin

e) Adherin



13.2) Neurotransmitters are released as ____, with each vesicle adding its contents ____

to the contents released from others.

a) A flowing stream; Exponentially

b) A flowing stream; Incrementally

c) Packets; Exponentially

d) Packets; Incrementally

13.3) The extent of temporal summation and depolarization of the end-plate-potential is

dependent upon:

a) The extend to which ACh is released

b) The strength of the presynaptic stimulus

c) The duration of the presynaptic stimulus

d) The extent to which the channels are activated

e) All of the above

14) A synaptic delay occurs between the arrival of an action potential at the nerve

terminal and the generation of an EPSP at the postsynaptic site. This delay has been

measured in animal models (squid, frog) to be about:

a) 0.2 – 0.5 ms

b) 0.5 – 40 ms

c) 40 – 50.5 ms

d) 55 – 100 ms

e) 112 – 286 ms

15.1) Which of the following would definitely NOT be let through the postsynaptic

membrane by acetylcholine?

a) K+

b) Ca++

c) Cl-

d) Na+

e) H+

15.2) By what process is ACh broken down by AChE into acetate and choline (which is

actively taken back in by the presynaptic axon terminal)?

a) Hydrolysis

b) Reduction

c) Oxidation

d) Hydrogination

e) Ozonolysis

15.3) Which of the following neurotransmitter inactivation mechanisms is associated

with transmitter-sensitive transport molecules and serotonin?

a) Diffusion

b) Reuptake

c) Metabolism

15.4) Which of the following neurotransmitter inactivation mechanisms is associated

with movement out of the narrow synaptic cleft and norepinepherine?

a) Diffusion

b) Reuptake

c) Metabolism



15.5) Neurotransmitter inactivation by metabolism involves enzymes in the synaptic

cleft, which can include:

a) Norepinepherine

b) Serotonin

c) ACh

d) AChE

e) Choline

16.1) Neuron-to-neuron signaling that utilizes neurotransmitters involves one neuron

releasing and being sensitive to ____ neurotransmitter.

a) 1

b) 2

c) 4

d) 8

e) Many

16.2) Neuron-to-neuron signaling can involve second messengers. Which of the

following is the correct sequence for the cyclic adenosine monophosphate (cAMP)

system? (arrows denote activation)

a) Ion channels open => Receptor proteins => Linking proteins => Enzymes that

synthesize cAMP => Other enzymes

b) Enzymes that synthesize cAMP => Linking proteins => Receptor proteins =>

Other enzymes => Ion channels open

c) Enzymes that synthesize cAMP => Receptor proteins => Linking proteins =>


d) Linking proteins => Receptor proteins => Enzymes that synthesize cAMP =>


e) Receptor proteins => Linking proteins => Enzymes that synthesize cAMP =>


5 – Membrane Receptors, Second Messengers, and Signal Transduction Pathways

1) Some regulatory substances, such as steroid and thyroid hormones ____ the cell and

bind to receptors that are transcription factors activated by binding the hormone. In this

way, the hormone influences the transcription of certain genes.

a) Leave

b) Enter

c) Remain outside of

d) Remain inside of

e) Are not involved with

2) Agonists exert their influences from ____ the cell.

a) Outside of

b) Inside of

c) The nucleus of

d) The mitochondria of

e) The lysosomes of

3) Which of the following is the correct order, from longest distance to least, for how far

a regulator may travel to reach its target cell?

a) Paracrine > Autocrine > Endocrine



b) Autocrine > Endocrine > Paracrine

c) Autocrine > Paracrine > Endocrine

d) Endocrine > Autocrine > Paracrine

e) Endocrine > Paracrine > Autocrine

4) Phosphorylation plays a central role in eliciting cellular response. Protein kinase ____

particular proteins and protein phosphatase ____ particular proteins.

a) Phosphorylates; Phosphorylates

b) Dephosphorylates; Dephosphorylates

c) Phosphorylates; Dephosphorylates

d) Dephosphorylates; Phosphorylates

5) Which of the following major classes of agonist-activated protein kinases is NOT

matched correctly?

a) cAMP => PKA

b) cGMP => PKG

c) Ca++ => Threonine

d) Diacylgycerol => PKC

6.1) Which of the following is NOT a second messenger that regulates the activities of

protein kinases?

a) Inositol

b) 1,4,5-triphosphate (InsP3)

c) Diacylglycerol

d) Ca++

e) ACh

6.2) cAMP is characterized by all of the following EXCEPT:

a) Is formed using adenylyl cyclase

b) Activates PKA

c) Phosphorylates serine residues

d) Is broken down by phosphodiesterase

e) Is a product of a G-protein pathway

7) cAMP-dependent protein kinase does all of the following EXCEPT:

a) Is also known as PKA

b) Dephosphorylates enzymes in the cAMP pathway

c) Phosphorylates more than one enzyme

8) All of the following are true EXCEPT:

a) Calmodulin is activated by 4 Ca++ anions

b) Calmodulin enhances the phosphorylating ability of calmodulin-dependent

protein kinases

c) Calmodulin activity would be enhanced upon the formation of IP3 in the cell

d) Calmodulin-dependent protein kinases do not require calcium in their pathway

9) Which of the following does NOT activate protein kinases of the C family?

a) cGMP

b) Ca++

c) Diacylglycerol

d) Membrane phospholipids

e) Breakdown products of membrane phospholipids



10) Insulin and certain growth factors bind to membrane receptors that are themselves

protein kinases that phosphorylate protein substrates on ____ residues.

a) Serine

b) Thronine

c) Tyrosine

d) Adenine

e) Adenosine

11) G proteins have a high affinity for ____ in their active state and preferentially bind

____ in their inactive state. When certain membrane receptors have agonist molecules

bound to them, they interact with specific G proteins to promote the conversion of G

proteins to their activated state by binding ____.

a) GTP; GDP; GDP

b) GTP; GDP; GTP

c) GDP; GTP; GDP

d) GDP; GTP: GTP

12) G proteins affect second messenger levels in cells by altering concentrations of:

a) Adenylyl cyclase

b) cGMP phosphodiesterase

c) PKA & PKC

d) Calmodulin-dependent kinase

e) A & B

13) Ca++ channels may be modulated directly by ____ and indirectly by ____.

a) G proteins; G proteins

b) Second messenger-dependent protein kinases; Second messenger-dependent

protein kinases

c) Second messenger-dependent protein kinases; G proteins

d) G proteins; Second messenger-dependent protein kinases

14) G proteins regulate all of the following effectors EXCEPT:

a) Phospholipase A1

b) Phospholipase A2

c) Phospholipase C

d) Phospholipase D

e) Certain K+ channels

15) Which of the following is NOT true regarding the G protein kinase-mediated signal-

transduction pathway?

a) Amplification can occur at many points

b) The ligand-bearing receptor interacts with a G protein and activates it; the

activated G protein binds GTP

c) The activated G protein interacts with only one effector to activate or inhibit it

d) The increase or decrease of the concentration of a second messenger changes

the activity of one or more second messenger-dependent protein kinases

e) The level of phosphorylation of an enzyme or an ion channel is altered or an

ion channel activity changes because of interaction with an activated G protein

and causes the final cellular response

16.1) Which of the following is the correct pathway order for the G protein Gq?



(phophatidylinositol 4,5-bisphosphate = PIP2; inositol 1,4,5-triphosphate = IP3;

diacylglycerol = DAG; ! isoform of phospholipase C = PLC!)

a) Gq => PIP2 => PLC# => IP3 & DAG

b) Gq => PLC# => PIP2 => IP3 & DAG

c) Gq => PLC# => DAG => IP3 & PIP2

d) Gq => PLC# => IP3 => DAG & PIP2

e) Gq => PIP2 => IP3 & DAG => PLC#

16.2) In the Gq pathway, after cleavage creates DAG, where does DAG go?

a) Sarcoplasmic reticulum

b) Stays in the membrane

c) Leaves the cell

d) Enters the cell

e) Enters the mitochondria

17) In the Gq pathway, after cleavage creates IP3, it travels through the cytoplasm to its

receptor on the ____ and allows ____ to exit, which increases cytosolic concentration of

that ion.

a) Mitochondria; Ca++

b) Endoplasmic reticulum; Ca++

c) Mitochondria; Na+

d) Endoplasmic reticulum; Na+

e) Nucleus; Ca++

18) Aspirin and other nonsteroidal antiinflammatory agents inhibit the conversion of

arachidonic acid to inflammatory prostaglandins, prostacyclins, and thromboxanes.

Arachidonic acid, along with phospholipids, are released by:

a) Certain K+ channels

b) Phospholipase D

c) Phospholipase C

d) Phospholipase A2

e) Phospholipase A1

19) The transmembrane portion of the G protein-coupled receptor has how many alpha

helices (each being made of 22 to 28 hydrophobic amino acids)?

a) 3

b) 14

c) 5

d) 12

e) 7

20.1) Phosphorylation decreases the receptor's ability to influence its effector protein.

a) True

b) False

20.2) Agonist down-regulation decreases the number of receptors by subjecting them to:

a) Organophosphates

b) Mitochondria

c) Lysosomes

d) Pinocytosis

e) Endoplasmic reticulum



21) During the activation process of the heterotrimeric G protein, which subunit releases

GDP from its nucleotide binding site, binds GTP, then dissociates from the other two

subunits?

a) ! (alpha)

b) # (beta)

c) $ (gamma)

22) Adenylyl cyclase, the enzyme that produces cAMP, is the prototype for G protein-

mediated signal-transduction pathways. Certain stimulatory agonists (e.g. epinephrine)

and certain inhibitory agonists (e.g. adenosine) cause the release of the ____ (stimulatory)

and ____ (inhibitory) heterotrimeric G protein subunits respectively, which activate

adenylyl cyclase.

a) !s, #i

b) #s, !i

c) $s, $i

d) #s, #i

e) !s, !i

23) Cholera toxin catalyzes the transfer of ADP-ribose to ____, leading to increased

cAMP, leading to massive secretion of Cl-, Na+, and water into the intestinal lumen.

a) #i

b) #s

c) !i

d) !s

e) $i

24) Gi-type G proteins act on (and inhibit):

a) Diacylglycerol

b) Adenylyl cyclase

c) PLC#

d) IP3

e) Ca++

25) The action of acetylcholine on muscarinic receptors to increase K+ conductance of

the pacemaker cells in the sinoatrial node of the heart is the major mechanism whereby

parasympathetic nerves slow the heart rate. This is an example of a case where certain ion

channels are ____ modulated by G proteins ____ the help of second messengers. Another

example is certain extracellular agonist, such as acetylcholine and $-aminobutyric acid.

a) Indirectly; With

b) Indirectly; Without

c) Directly; With

d) Directly; Without

26.1) The activation of monomeric GTP-binding proteins is enhanced by____, and

inactivation is promoted by ____.

(guanine nucleotide exchange factors = GEFs; GTPase-activating proteins = GAPs)

a) GEFs; GEFs

b) GAPs; GAPs

c) GEFs; GAPs

d) GAPs; GEFs



26.2) Which of the following monomeric GTP-binding protein subfamilies is/are

involved in the signal-transduction pathways that link growth factor receptor tyrosine

kinases to their intracellular effects?

a) Ras-like proteins

b) Rho-like proteins

c) Rab-like proteins

d) A & B

e) B & C

27) In the presence of micromolar levels of cAMP, each PKA regulatory subunit binds

____ molecule(s) of cAMP, activating catalytic subunits. The active catalytic subunit

phosphorylates target proteins on particular serine and threonine residues.

a) 1

b) 2

c) 3

d) 4

e) 6

28) Myosin light-chain kinase, a calmodulin-dependent protein kinases, plays a central

role in regulating the contraction of smooth muscle. Which of the following is required

for this to occur?

a) Na+

b) Cl-

c) K+

d) Mg++

e) Ca++

29) The primary action of certain lipophilic tumor-promoting substances, most notably

the phorbol esters, is direct activation of Protein Kinase C (PKC). PKC is activated by

membrane lipids (e.g. DAG) and:

a) cAMP

b) cGMP

c) IP3

d) Ca++

e) Mg++

30.1) Receptors for all of the following have tyrosine kinase activity EXCEPT:

a) Insulin

b) Glucagon

c) Fibroblast growth factor

d) Epidermal growth factor

e) Nerve growth factor

30.2) The binding of hormone or growth factor to its receptor triggers multiple cellular

responses, including all of the following EXCEPT: a) Ca++ efflux

b) Increased Na+/H+ antiport activity

c) Stimulation of the uptake of sugars

d) Stimulation of the uptake of amino acids

e) Stimulation of PLC# to hydrolize PIP2

31) Which of the following “out-of-control” kinase would lead to cancer?



a) Ca++/calmodulin-dependent protein kinase

b) Receptor-associated tyrosine kinase

c) Protein-tyrosine kinase

d) Histidine-specific protein kinase

e) Aspartic acid/glutamic acid-specific protein kinase

32) What reverses the work done by protein kinases? The two major classifications of

these are protein-serine/threonine and protein-thyrosine.

a) Protein phosphatase

b) Protein dephosphoralate

c) Protein biphosphus

d) Adenosine phosphatase

e) Adenosine dephosphoralate

33) Atrial natriuretic peptide (ANP) is released by cells in the atrium of the heart in

response to ____ atrial pressure. This hormone ____ the excretion of NaCl and water and

____ certain blood vessels. The membrane receptors for ANP themselves possess

guanylyl cyclase activity that is stimulated when ANP is bound to the receptor. No

second messenger is required to activate guanylyl cyclase.

a) Increases; Decreases; Relaxes

b) Decreases; Decreases; Constricts

c) Decreases; Decreases; Relaxes

d) Increased; Increases; Constricts

e) Increased; Increases; Relaxes

34.1) Increased cytosolic levels of which of the following is often the stimulus for

enhanced formation and release of nitric oxide (NO)?

a) Na+

b) Cl-

c) K+

d) Mg++

e) Ca++

34.2) NO stimulates a soluble guanylyl cyclase in the target cell and thereby elevates the

intracellular concentration of cGMP, thus stimulating cGMP-dependent protein kinase.

What other affect does NO have?

a) Bronchioconstriction

b) Bronchiodilatation

c) Vasoconstriction

d) Vasodilatation

6 – Striated Muscle

Match the following skeletal muscle fiber properties with their types:

1.1) Mixture of glycolytic and oxidative capacities a) Type I

1.2) Low oxidative, high glycolytic, fast twitch b) Type IIa

1.3) High oxidative, slow twitch c) Type IIb

1.4) High myoglobin content, high resistance to fatigue, and small diameter

1.5) Low capillary density and low mitochondrial density

1.6) Low troponin affinity for Ca++

1.7) Which of the following is the correct order of recruitment for skeletal muscle fibers?



a) Type IIa > Type IIb > Type I

b) Type IIa > Type I > Type IIb

c) Type IIb > Type IIa > Type I

d) Type I > Type IIb > Type IIa

e) Type I > Type IIa > Type IIb

2.1) Which of the following is in the correct order from largest to smallest?

a) Myofibril > Myofiliament > Muscle fiber > Muscle

b) Muscle fiber > Muscle > Myofibril > Myofiliament

c) Muscle fiber > Muscle > Myofiliament > Myofibril

d) Muscle > Muscle fiber > Myofibril > Myofiliament

e) Muscle > Muscle fiber > Myofiliament > Myofibril

2.2) Which of the following is considered the smallest unit that contains all metabolic

machinery?

a) Muscle

b) Myofilament

c) Muscle fiber

d) Myofibril

3) Thick filaments, made from myosin, are aniosotropically aligned. Myosin molecules

are arranged in a regular helical pattern, with crossbridges every:

a) 30 degrees

b) 60 degrees

c) 90 degrees

d) 180 degrees

e) 270 degrees

4.1) Which of the following forms the “backbone” of the thick filament?

a) Myosin subfragment 1 (S1)

b) Myosin subfragment 2 (S2)

c) Light meromyosine (LMM)

d) Heavy meromyosin (HMM)

e) Myosin light chains (LCs)

4.2) The myosin subfragment 2s (S2) are associated with how many S1s?

a) 0

b) 1

c) 2

d) 4

e) 8

4.3) How many alpha-helices form the LMMs and S2s?

a) 5

b) 4

c) 3

d) 2

e) 1

4.4) Which of the following contains an actin binding domain, an ATP binding site, and a

region of myosin-ATPase activity?

a) Myosin subfragment 1 (S1)

b) Myosin subfragment 2 (S2)



c) Light meromyosine (LMM)

d) Heavy meromyosin (HMM)

4.5) The essential, or alkali, LCs (LC1, LC3) contain a Ca++ binding site, which helps

control:

a) The actin binding domain

b) The ATP binding site

c) Myosin-ATPase activity

d) Smooth muscle contraction

e) Mg++ regulation of LC2s

4.6) The accessory C protein runs ____ across the thick filament and keeps the myosin

molecules aligned. The M protein joins the myosin at the ____ of the thick filament.

a) Transversely; Peripheral helices

b) Transversely; Central bare zone

c) Longitudinally; Peripheral helices

d) Longitudinally; Central bare zone

5.1) F-actin (a double alpha-helix of G-actin) has the capacity to:

a) Decrease myosin-ATPase activity

b) Increase myosin-ATPase activity

c) Decrease the actin binding domains

d) Increase the actin binding domains

e) Block the ATP binding site

5.2) What is the ratio of tropomyosin (Tm) to actin on thin filaments, as well as the ratio

of troponin (Tn) to G-actin?

a) 1:1

b) 1:2

c) 1:3

d) 1:5

e) 1:7

Match the following functions with their functional domains of troponin (Tn):

5.3) Modifies actomyosin interactions at low Ca++ a) Troponin T (TnT)

5.4) Contains Ca++ binding site b) Troponin I (TnI)

5.5) Attaches to tropomyosin c) Troponin C (TnC)

Match the following functions with their intermediate filament proteins:

6.1) Anchors myofilaments to the sarcolemma a) TITIN

6.2) Associated with the z-line b) NEBULIN

6.3) Associated with myosin c) DYSTROPHIN

6.4) Associated with actin d) ALPHA-/BETA-ACTININ

7 .1) Which part of the sarcomere contains only thick filaments?

a) I-band

b) A-band

c) H-zone

d) Z-line

e) M-line

7.2) Which part of the sarcomere may contain thick filaments, thin filaments, and

intermediate filaments (overlapping)?

a) I-band



b) A-band

c) H-zone

d) Z-line

e) M-line

7.3) Which part of the sarcomere is associated with the function of crosslinking myosins?

a) I-band

b) A-band

c) H-zone

d) Z-line

e) M-line

8.1) Shortening during muscle contraction is due to shortening of sarcomeres as well as

shortening of the proteins themselves.

a) True

b) False

8.2) During the sliding filament mechanism of muscle contraction, the length of ____

remain(s) constant while the ____ shorten(s).

a) Myofilament; A-band

b) A-band; I-band

c) Myofilament & H-zone; I-band & A-band

d) Myofilament & A-band; I-band & H-zone

e) I-band & A-band; Myofilament & H-zone

9.1) Rigor (rigot mortis) is defined as the absence of:

a) Ca++

b) Actin

c) Myosin

d) ADP

e) ATP

9.2) The initial reaction, which leads to the binding of actin and myosin S1 (M.ADP.Pi or

M.ADP to A.M.ADP.Pi) is initiated by:

a) Active increase in intracellular Ca++

b) Active increase in extracellular Ca++

c) Passive increase in intracellular Ca++

d) Passive increase in extracellular Ca++

e) Active decrease in intracellular Ca++

9.3) The “power stroke” (putative force generation step) occurs after the release of ____

into the sarcoplasm.

a) ATP

b) ADP

c) Pi

d) Ca++

e) Mg++

9.4) During the “power stroke”, motion of S1 goes from ____ degrees to ____ degrees, in

relation to the thin filament.

a) 90; 45

b) 45; 90

c) 90; 180



d) 180; 90

e) 0; 90

9.5) The formation of the actomyosin complex (A.M.ADP.Pi) enhances ATPase activity

of myosin by how many order of magnitude?

a) 1 (10 times)

b) 2 (100 times)

c) 3 (1,000 times)

d) 4 (10,000 times)

e) 5 (100,000 times)

9.6) During the initial step of the cross-bridge cycle, what does calcium bind to?

a) ATP

b) Actin

c) Myosin

d) Troponin

e) Tropomyosin

10.1) The function of T-tubules is to:

a) Move extracellular fluid into the sarcolemma

b) Connect the feet of the sarcoplasmic reticulum

c) Dampen the spread of the action potential

d) Allow for rapid spread of the action potential

e) Increase extracellular Ca++ concentrations

10.2) What is the ratio of feet proteins to Ca++ release channels of the sarcoplasmic

reticulum cisternae?

a) 1:1

b) 1:2

c) 1:3

d) 1:5

e) 1:7

10.3) Within skeletal muscle, what is contained in a triad?

a) 3 T-tubule and 3 junctional sarcoplasmic reticulums

b) 2 T-tubule and 2 junctional sarcoplasmic reticulums

c) 2 T-tubule and 1 junctional sarcoplasmic reticulums

d) 1 T-tubule and 1 junctional sarcoplasmic reticulums

e) 1 T-tubule and 2 junctional sarcoplasmic reticulums

11) What is the direct function of feet proteins (dihydropyridine receptors, DHPRs),

which link T-tubules to the junctional sarcoplasmic reticulum?

a) Stimulate Ca++ channels to intake calcium

b) Stimulate Ca++ channels to release calcium



e) Respond to the T-tubule action potential

12) What is the function of ryanodine receptors (RYRs)?

a) Stimulate Ca++ channels to intake calcium

b) Stimulate Ca++ channels to release calcium





e) Respond to the T-tubule action potential

13.1) Which part of the major sarcoplasmic reticulum regions is responsible for rapid

requestration of Ca++ once it is released from the SR?

a) The junctional SR

b) The SR terminal cisternae regions

c) The longitudinal SR

13.2) Which part of the major sarcoplasmic reticulum regions holds most of the Ca++?

a) The junctional SR

b) The SR terminal cisternae regions

c) The longitudinal SR

14.1) Phosphorylation of phospholamban (plb), which is in the longitudinal SR, results in

what relationship of ATP use (ATPase) to Ca++ uptake?

a) Constant

b) Direct, proportional

c) Direct, inversely proportional

d) Exponential, positive

e) Exponential, negative

14.2) Calsequesterine is found in the SR terminal cisternae regions and reduces the

amount of free Ca++ within the SR. The protein-binding ratio of calcium (per moles) to

calsequesterine (per moles) is:

a) 1:3

b) 1:13

c) 1:23

d) 1:33

e) 1:43

14.3) The work of calsequesterine reduces free Ca++ within the SR from 20mM to about:

a) 10mM

b) 5mM

c) 1mM

d) 0.5mM

e) 0.1mM

15) Excitation in E-C coupling involves calcium release and generation of a Ca++

transient. This process has a delay of about ____ between electrical and physical events.

a) 1 "s

b) 10 "s

c) 1 ms

d) 10 ms

e) 1 s

16) Which of the following is NOT true of the contraction portion of E-C coupling as

calcium concentrations rise?

a) Ca++ binds to TnC and the Tn molecule is sterically altered

b) Tm normally covers the myosin binding sites on actin

c) Tm is pulled into the groove between the two alpha-helical actin strands

d) The myosin binding sites remain covered

e) The actomyosin complex is initiated and crossbridge cycling is initiated

17.1) Which of the following maintains the blocking activity of tropomyosin?



a) TnC

b) TnI

c) TnT

17.2) Which of the following has four divalent-ion binding sites, with two high affinity

(Mg++) and two low affinity (Ca++)?

a) TnC

b) TnI

c) TnT

18) What can be said about the slope of the graph for calcium concentration versus force

production in the region of the myofibril? This relationship is also saturable, so a further

increase in calcium concentration at high-force will lead to little increase of force.

a) Shallow positive slope

b) Shallow negative slope

c) Steep positive slope

d) Steep negative slope

e) No slope

19) Ca++ activation of striated muscle is a disinhibition of the contractile process. When

does this disinhibition begin?

a) When TnI binds with actin

b) When TnT controls tropomyosin

c) When tropomyosin is moved into the actin grooves

d) When tropomyosin maintains blocking activity

e) When TnC binds with Ca++

20) What is required for relaxation to occur, so that tropomyosin can return to its original

blocking position?

a) Ca++

b) ATP

c) ADP

d) Actin

e) Myosin

21.1) Which of the following is true regarding Ca++ binding (and unbinding) to TnC

sites?

a) Ca++ binds and unbinds at the same rate

b) Ca++ binds slower than it unbinds

c) Ca++ binds faster than it unbinds

21.2) Compared with a single twitch action potential, action potentials for tetanus will

always give a stronger initial force.

a) True

b) False

21.3) Which of the following energetic methods is used for continual muscle contraction?

a) Intracellular ATP stores

b) Phosphocreatine

c) Glycolytic stores

d) Oxidative phosphorylation

22) Which of the following is activated at the lowest level of CNS stimulation?

a) Type I fibers



b) Type IIa fibers

c) Type IIb fibers

23.1) The length-tension relationship for muscle yields a(n) ____ curve for passive

stretch and a(n) ____ curve for active stretch, with the total force being the sum of the

two components.

a) Decreasing; Increasing

b) Increasing; Decreasing

c) Logarithmic; Decreasing then increasing

d) Logarithmic; Increasing then decreasing

e) Constant; Logarithmic

23.2) The length-tension relationship of muscle fibers is directly related to:

a) Thin filaments

b) Thick filaments

c) Concentration of actin

d) Concentration of myosin

e) Overlap of thin and thick filaments

24.1) Which of the following is NOT true for maximal velocity (Vmax) of shortening of

a muscle fiber?

a) Proportional to the myosin-ATPase rate

b) Is a measure of inherent crossbridge velocity

c) Depends on the degree of filament overlap (length-dependent)

d) Attained when the muscle is completely unloaded

e) Depends upon the initial load applied on the muscle

24.2) For the force-velocity relationship, as load increases (toward maximal force) the

maximal speed of shortening will:

a) Remain constant

b) Increase

c) Decrease

d) Increase then decrease

e) Decrease then increase

24.3) For the force-power relationship, as load increases (toward maximal force) the

power produced will:

a) Remain constant

b) Increase

c) Decrease

d) Increase then decrease

e) Decrease then increase

25) The low-resistance pathways between cardiac muscle cells are ____, which are ____

synapses.

a) Gap junctions; Electrical

b) Gap junctions; Chemical

c) Neuromuscular junctions; Electrical

d) Neuromuscular junctions; Chemical

e) Nexi; Electrical

26.1) In skeletal muscle, T-tubules are associated with ____ and in cardiac muscle they

are associated with ____.



a) A-I transitions; M-lines

b) A-I transitions; Z-lines

c) M-lines; A-I transitions

d) Z-lines; A-I transitions

e) M-lines; Z-lines

26.2) The structure in cardiac muscle that is similar to skeletal triads contains:

a) 3 T-tubule and 3 junctional sarcoplasmic reticulums

b) 2 T-tubule and 2 junctional sarcoplasmic reticulums

c) 2 T-tubule and 1 junctional sarcoplasmic reticulums

d) 1 T-tubule and 1 junctional sarcoplasmic reticulums

e) 1 T-tubule and 2 junctional sarcoplasmic reticulums

26.3) Compared with skeletal muscle, cardiac muscle has ____ as many Ca++ release

channels and sarcoplasmic reticulum Ca++ ATPases.

a) Just

b) 1/2

c) 1/3

d) 1/4

e) Twice

26.4) During the cardiac action potential plateau phase, the L–type calcium current

causes a ____ movement of calcium ____ the cell, which is responsible for initiation of

the calcium-induced calcium release (CICR) process.

a) Large; Into

b) Large; Out of

c) Small; Into

d) Small; Out of

26.5) The calcium associated with CICR is sequestered in the sarcoplasmic reticulum for

release during the next heart beat. A new amount of calcium is allowed to cross the cell.

This calcium is called:

a) Initial calcium

b) Regulated calcium

c) Substantial calcium

d) Recycled calcium

e) Trigger calcium

27.1) Regarding restorative Ca++ processes, the Na+/Ca++ exchanger moves ____ Na+

inward for each Ca++ extruded from the cell.

a) 1

b) 2

c) 3

d) 4

e) 5

27.2) The activity of the exchanger is ____ as the cell ____, since this tends to pull more

sodium into the cell and extrudes more calcium.

a) Increased; Repolarizes

b) Decreased; Repolarizes

c) Increased; Depolarizes

d) Decreased; Depolarizes



27.3) Digitalis, an inotropic drug, works by keeping calcium within the sarcoplasmic

reticulum so it is available during subsequent cardiac activations. It works on the

exchanger by _____ sodium within the cell and _____ the effectiveness of calcium

extrusion.

a) Decreasing; Increasing

b) Decreasing; Decreasing

c) Increasing; Increasing

d) Increasing; Decreasing

28.1) According to Starlings Law of the Heart, an increase in left ventricular end-

diastolic fiber length would result in:

a) Increased ventricular force of contraction and decreased stroke volume

b) Increased ventricular force of contraction and increased stroke volume

c) Decreased ventricular force of contraction and decreased stroke volume

d) Decreased ventricular force of contraction and increased stroke volume

28.2) What is the importance of the high passive force exhibited by cardiac muscle?

a) Allows the heart to increase preload to optimal volume

b) Allows the heart to pump whatever volume of blood it receives

c) Allows the heart to contract as a unit

d) Allows the heart to overcome the pressure differences between chambers

e) Allows the heart valves to remain in place without significant movement

7 – Smooth Muscle

1) Which of the following distinguishes smooth muscle from other types of muscle?

a) Largest in cell diameter

b) Are more rectangular-shaped than spindle-shaped

c) Lack of dense bodies

d) Cannot regenerate or use Ca++

e) Lack of striations

2) Which of the following best describes the general electrical activities of single-unit

and multi-unit smooth muscle cells?

a) Single-unit acts independently and multi-unit acts independently

b) Single-unit acts independently and multi-unit communicates with neighbors

c) Single-unit acts communicates with neighbors and multi-unit acts

independently

d) Single-unit acts communicates with neighbors and multi-unit communicates

with neighbors

3.1) All of the following are true regarding smooth muscle EXCEPT:

a) Smooth muscle cells are relatively small compared with skeletal muscle cells

b) Instead of sarcomeres, it contains dense bodies, which are like Z-lines

c) Gap junctions electrically couple the smooth muscle cells

d) Smooth muscle contains caveolae instead of T-tubules

e) Smooth muscle does not contain sarcoplasmic reticulum

3.2) Thick filament regulation is used because smooth muscle does NOT contain

a) Actin

b) Myosin

c) Tryopomyosin



d) Troponin

e) Caveolae

4) Thick and thin filaments in smooth muscle are situated ____ to the long axis and thus

cause the muscle to ____ as it contracts. (Thin filaments attach to dense bodies)

a) Oblique; Twist

b) Parallel; Twist

c) Transverse; Twist

d) Oblique; Stretch

e) Parallel; Stretch

5) Some hormones and neurotransmitters may increase the cytosolic calcium

concentration by depolarizing the smooth muscle membrane. This activates voltage-gated

calcium channels and can lead to Ca++ induced Ca++ release via ____ receptors. Many

hormones and neurotransmitters use a process called pharmacomechanical coupling to

change cytosolic calcium concentrations ____ membrane potential.

a) Ryanodine; While drastically changing

b) Ryanodine; Without altering

c) Dihydropyridine; While drastically changing

d) Dihydropyridine; Without altering

6.1) Striated muscle is a ____ system and smooth muscle is a ____ system.

a) Disinhibition; Disinhibition

b) Direct activation; Direct activation

c) Disinhibition; Direct activation

d) Direct activation; Disinhibition

e) Disinhibition; Indirect activation

6.2) What allows smooth muscle myosin to interact with actin?

a) Ca++

b) ATP

c) ADP

d) Troponin

e) Myosin light-chain kinase

7) The SR Ca++ pump (SERCA) moves calcium ____ the cell and the sarcolemmal

3Na+/Ca++ antiporter and sarcolemmal Ca++ pump move calcium ____ the cell.

a) Into; Out of

b) Out of; Into

c) Into; Into

d) Out of; Out of

8) Smooth muscle tone can be decreased by ____ myosin light-chain kinase or ____

myosin dephosphorylation (phosphatase activity).

a) Inhibiting; Inhibiting

b) Activating; Activating

c) Inhibiting; Activating

d) Activating; Inhibiting

9) #2-adrenergic receptor agonists cause bronchiolar smooth muscle relaxation. This

involves ____ cAMP levels, which ____ myosin light-chain phosphorylation because of

cAMP-dependent phosphorylation of myosin light-chain kinase.

a) Increasing; Inhibit



b) Increasing; Activate

c) Decreasing; Inhibit

d) Decreasing; Activate

10) The vasodilator nitroglycerine reverses vasoconstriction by ____ cGMP levels in

smooth muscle. This activates myosin phosphatase and ____ levels of myosin light-chain

phosphorylation, which relaxes smooth muscle.

a) Increasing; Increases

b) Increasing; Decreases

c) Decreasing; Increases

d) Decreasing; Decreases

11) During the latch state of smooth muscle, ATP use is ____ while maintaining

contraction and the crossbridges (actin and myosin) are held in the rigor state. The

dephosphorylated myosin is predicted to detach from actin much ____ than

phosphorylated myosin. a) Low; Slower

b) High; Faster

c) Low; Slower

d) High; Faster

12) What causes hypertrophy and hyperplasia in smooth muscle?

a) Increased electrochemical workload

b) Decreased electrochemical workload

c) Increased mechanical workload

d) Decreased mechanical workload

8 – The Autonomic Nervous System and Its Control

1) Which of the following is NOT true regarding the autonomic nervous system (ANS)?

a) It is a motor system associated with smooth muscle

b) It is associated with cardiac muscle

c) It is associated with glands

d) It is directly accessible to voluntary control

e) Homeostasis is a major function of the system

2.1) The cell bodies of the sympathetic preganglionic neurons are located in the

intermediolateral (and medial) cell columns (IML). The motor axons are small

myelinated B fibers or in some cases unmyelinated C fibers. They pass from the spinal

nerves into the white communicating rami. When the sympathetic preganglionic axons in

a given white ramus reach the sympathetic paravertebral ganglion of the same segment,

they may do all of the following EXCEPT: a) Synapse in that ganglion

b) Travel directly to the heart without synapse

c) Descend and synapse in a paravertebral ganglion

d) Ascend and synapse in a paravertebral ganglion

e) Continue through a splanchnic nerve to synapse in a prevertebral ganglion

2.2) Sympathetic postganglionic neurons are located in the paravertebral and prevertebral

ganglia. The axons are ____ that distribute either to the body wall or to the viscera in the

body cavities. If they are destined for the body wall, they pass from a paravertebral

ganglion into a spinal nerve via a ____ communicating ramus.



a) Myelinated B fibers; Gray

b) Myelinated B fibers; White

c) Unmyelinated C fibers; Gray

d) Unmyelinated C fibers; White

2.3) Sympathetic preganglionic neurons that supply the head have axons leaving the

spinal cord via ____ communicating rami at the levels of ____.

a) White; T1-T2

b) White; C1-C2

c) Gray; T1-T2

d) Gray; C1-C2

2.4) Preganglionic parasympathetic cell bodies are located in:

a) The brainstem

b) C1-T2

c) T1-L2

d) S2-S4

e) A & D

Match the following cranial nerve nuclei that contain preganglionic parasympathetic

neurons with their associated cranial nerve.

2.5) Nucleus ambiguous a) CN III

2.6) Superior salivatory nucleus b) CN VII

2.7) Inferior salivatory nucleus c) CN IX

2.8) Edinger-Westphal nucleus d) CN X

Match the following ganglion (for cranial parasympathetic preganglionic axons) with

their associated cranial nerve.

2.9) Otic ganglion a) CN III

2.10) Ciliary ganglion b) CN VII

2.11) Ganglia in walls of target viscera c) CN IX

2.12) Sphenopalatine & submaxillary ganglia d) CN X

2.13) The sympathetic nervous system is a(n) ____ system and the parasympathetic

nervous system is a(n) ____ system.

a) Adrenergic; Adrenergic

b) Cholinergic; Cholinergic

c) Adrenergic; Cholinergic

d) Cholinergic; Adrenergic

3) The adrenal medulla (organ) receives:

a) Postganglionic sympathetic fibers

b) Postganglionic parasympathetic fibers

c) Preganglionic sympathetic fibers

d) Preganglionic parasympathetic fibers

e) No autonomic nervous system innervation

4) Which of the following can show reflexive movements when separated from the

autonomic nervous system?

a) Adrenal medulla

b) Heart

c) Kidneys

d) Liver



e) Gastrointestinal tract

5) Control of organ activity by sympathetic and parasympathetic systems should be view

as occurring:

a) Via direct opposition

b) Via indirect opposition

c) Rhythmically

d) Spontaneously

e) Concurrently

6.1) Nicotinic receptors, an acetylcholine receptor on postganglionic neurons, is activated

by ____ and blocked by ____.

a) Nicotine; Curare

b) Nicotine; Atropine

c) Nicotine; Muscarine

d) Curare; Nicotine

e) Atropine; Nicotine

6.2) Muscarinic receptors, an acetylcholine receptor on postganglionic neurons, is

activated by ____ and blocked by ____.

a) Muscarine; Curare

b) Muscarine; Atropine

c) Muscarine; Nicotine

d) Curare; Muscarine

e) Atropine; Muscarine

6.3) What neurotransmitter is generally used by sympathetic postganglionic neurons?

a) Acetylcholine

b) Serotonic

c) Epinpherine

d) Norepinepherine

e) Atropine

6.4) The norepinepherine !-adrenergic receptor is mostly activated by ____ and can be

blocked with ____.

a) Norepinepherine; Phenoxybenzamine

b) Norepinepherine; Propranolol

c) Isoproterenol; Phenoxybenzamine

d) Isoproterenol; Propranolol

6.5) The norepinepherine #-adrenergic receptor is mostly activated by ____ and can be

blocked with ____.

a) Norepinepherine; Phenoxybenzamine

b) Norepinepherine; Propranolol

c) Isoproterenol; Phenoxybenzamine

d) Isoproterenol; Propranolol

6.6) Neurons of the enteric nervous system release all of the following EXCEPT:

a) Acetylcholine

b) Norepinepherine

c) Epinepherine

d) Serotonin

e) ATP



7) In general, preganglionic parasympathetic fibers are ____ than preganglionic

sympathetics fibers and postganglionic parasympathetics fibers are ____ than

postganglionic sympathetic fibers.

a) Longer; Shorter

b) Shorter; Longer

c) Longer; Longer

d) Shorter; Shorter

8) Along with some components of the limbic system, which of the following is a higher

center that regulates autonomic function?

a) Adrenal medulla

b) Cerebral cortex

c) Thyroid gland

d) Pituitary gland

e) Hypothalamus

9.1) Which of the following is NOT an originating site for brainstem pathways that

regulate the activity of autonomic preganglionic neurons?

a) Reticular formation

b) Edinger-Westphal nuclei

c) Raphe nuclei

d) Locus ceruleus complex

9.2) Autonomic reflexes are mediated by neural circuits in the spinal cord and brainstem.

The pathways involve interneurons that involve:

a) Visceral sensory receptors

b) Somatic sensory receptors

c) Visceral motor receptors

d) Somatic motor receptors

e) A & B

10.1) The peptide hormones oxytocin and vasopressin (neuromodulators in autonomic

neural circuits) are released from the tract that spans from the hypothalamus to the:

a) Adrenal medulla

b) Cerebral cortex

c) Thyroid gland

d) Pituitary gland

e) Hypothalamus

10.2) Neuroendocrine cells in a number of hypothalamic nuclei secrete hormones into the

___ system that supplies the ____ pituitary gland.

a) Caval; Anterior

b) Portal; Anterior

c) Caval; Posterior

d) Portal; Posterior

11) External thermoreceptors are located in the skin and central thermoreceptor neurons

are located in the:

a) Anterior pituitary

b) Posterior pituitary

c) Anterior hypothalamus

d) Posterior hypothalamus



e) Adrenal medulla

12) What type of feedback in involved in the bodies response to errors in internally set

temperature?

a) Closed-loop positive feedback

b) Closed-loop negative feedback

c) Open-loop positive feedback

d) Open-loop negative feedback

13) Heat-loss responses are mediated by all of the following EXCEPT:

a) Enteric nervous system

b) Autonomic nervous system

c) Somatic nervous system

d) Endocrine system

14) Cooling causes an increase in the activity of the thyroid gland and sympathetic

nervous system, both of which tend to raise heat production metabolically. It also results

in shivering, which involves ____ ____ muscle contractions.

a) Asynchronous smooth

b) Synchronous smooth

c) Asynchronous skeletal

d) Synchronous skeletal

15) Which of the following is NOT a major function of the heat production and

conservation centers in the brain?

a) Sweating

b) Shivering

c) Cutaneous vasodilation

d) Cutaneous vasoconstriction

e) Piloerection

16.1) Which of the following would NOT be an effect seen with M receptors?

a) Miosis (pupil constriction)

b) Increased intestinal motility

c) Penile erection

d) Urinary bladder relaxation

e) Vascular smooth muscle relaxation

16.2) #1 receptors work mostly on what organ?

a) Adrenal medulla

b) Heart

c) Kidneys

d) Liver

e) Gastrointestinal tract

16.3) Sympathetic contraction (of an effector organ) is usually associated with ____

receptors and sympathetic relaxation is associated with ____ receptors.

a) !; !

b) #; #

c) !; #

d) #; !

e) M; M



9 – General Principles of Endocrine Physiology

1) Which of the following is NOT true about the endocrine system?

a) Releases chemicals into the bloodstream for distribution throughout the body

b) Releases hormones that alter the metabolic activities of many different tissues

and organs

c) Produces effects that can last for hours, days, or even longer

d) Can alter gene activity of cells and growth processes

e) Produces an immediate (nearly instant) response

2) The elaborate endocrine signaling system likely evolved from a primitive one, as it

now has the ability to signal surrounding cells via interstitial fluid. This is called:

a) Endocrine function

b) Neurocrine function

c) Paracrine function

d) Autocrine function

e) Intracrine function

3) Which of the following acts on cells the greatest distance away?

a) Intracrine function

b) Neurocrine function

c) Paracrine function

d) Autocrine function

4) Which of the following is NOT true regarding a comparison of the endocrine system to

the nervous system?

a) Both neurons and endocrine cells are capable of secreting

b) Only neurons generate electrical potentials and can be depolarized

c) Some molecules serve as both a neurotransmitter and a hormone

d) The mechanism of action of both hormones and neurotransmitters requires

interaction with specific receptors in target cells

e) A similar process and repertory of proteins mediate exocytosis of secretory

granules and synaptic vesicles

5) During hypoglycemia, the body response is an interaction and coordination between

the nervous and endocrine systems. Which of the following participates in the neural

component of the response and not the endocrine component?

a) Anterior pituitary gland

b) Adrenal medulla

c) Adrenal cortex

d) Hypothalamus

e) Pancreatic islets

6.1) At the N terminus, a signal peptide directs the transfer of the preprohormone from

the ____ into the ____, soon making the active prohormone.

a) Nucleus; SER

b) Ribosome; ER

c) SER; Nucleus

d) ER; Ribosome

e) ER; Golgi

6.2) An increase in intracytoplasmic ____ concentration is needed for secretion of

hormones.



a) Ca++

b) Mg++

c) Raf

d) ATP

e) GTP-binding protein

6.3) Which of the following hormones is closely associated with cholesterol?

a) Catecholamine

b) Thyroid

c) Steroid

d) Prostaglandins

6.4) Which of the following is synthesized from tyrosine and stored in secretory

granules?

a) Catecholamine

b) Thyroid

c) Steroid

d) Prostaglandins

6.5) Which of the following is stored in a storage space (follicle) shared by a group of

surrounding endocrine cells?

a) Catecholamine

b) Thyroid

c) Steroid

d) Prostaglandins

7) In a negative feedback system (closed-loop), if an increase in hormone secretion

stimulates a greater output of product from the target cell, the product feeds back to the

gland to ____ hormone secretion.

a) Maintain

b) Increase

c) Decrease

d) Stop

8.1) Hormones such as ____ circulate unbound to other plasma constituents where

hormones such as ____ are bound to specific globulins (as well as albumin).

a) Steroid hormones; Catecholamines

b) Catecholamines; Peptide hormones

c) Thyroid hormones; Catecholamines

d) Thyroid hormones; Peptide hormones

e) Peptide hormones; Thyroid hormones

8.2) Strong protein binding will ____ a hormone’s plasma half-life.

a) Maintain

b) Increase

c) Decrease

9) Metabolic clearance rate (MCR) is an expression of the overall efficiency with which a

hormone is removed from plasma irrespective of the mechanism. It is the ____ of plasma

cleared of hormone per unit of ____.

a) Volume; Area

b) Volume; Hormone

c) Volume; Time



d) Area; Hormone

e) Area; Time

10) Which of the following describes the major steps of hormone signaling in order?

a) Hormone recognition => Intracellular signal generation => Increase in

intracellular process

b) Hormone recognition => Intracellular signal generation => Decrease in


c) Hormone recognition => Extracellular signal generation => Increase in


d) Hormone recognition => Extracellular signal generation => Decrease in


e) Hormone recognition => Intracellular signal generation => Increase or decrease

in intracellular process

11) Hormone recognition takes place via binding of the hormone (in a reversible fashion)

to a specific receptor that may be located within all of the following EXCEPT:

a) Plasma membrane

b) Cytoplasm

c) Nucleus via translocation

d) Inner mitochondrial membrane

12) Most hormones ____ the number of their own receptors; this helps prevent ____

hormone action on the cell.

a) Increase; Excess

b) Increase; Insufficient

c) Decrease; Excess

d) Decrease; Insufficient

13.1) When hormone-receptor association occurs within the plasma membrane of the

cell, the resultant complex is usually coupled with ____. When this association occurs

within the cytoplasm, the complex usually interacts with ____, where the response trigger

is in the hormone molecule itself as well as the receptor.

a) Membrane components; Membrane components

b) DNA; DNA

c) Membrane components; DNA

d) DNA; Membrane components

13.2) Which of the following is NOT a signal leading to second messengers within the

cytoplasm?

a) IP3

b) cAMP

c) cGMP

d) ATPase

e) Tyrosine Kinase

14.1) What shape does the dose-response curve for the action of a hormone often take?

a) Elliptical

b) Constant

c) Exponential

d) Sigmoidal

e) Stepwise



14.2) Which of the following is NOT a factor that affects the outcome of hormone

action?

a) Duration of hormone exposure

b) Concentration of rate-limiting enzymes

c) Size of receptors

d) Concentration of hormone

e) Cofactors and substrates

James Lamberg



AnswerKey

Physio #1

1.1) C

1.2) B

2) E

3) A

4) D

5.1) C

5.2) B

6) B

7) E

8.1) A

8.2) D

8.3) C

9.1) B

9.2) E

10) D

11) A

12) B

13.1) D

13.2) C

13.3) E

14.1) C

14.2) B

14.3) B

14.4) A

15.1) D

15.2) E

15.3) C

16) E

17.1) B

17.2) C

17.3) D

18.1) D

18.2) E

19.1) C

19.2) B

19.3) A

20) D

Physio #2

1.1) B

1.2) C

1.3) D

2.1) C

2.2) B

3.1) A

3.2) E

3.3) B

3.4) C

4.1) C

4.2) E

5.1) A

5.2) B

5.3) E

5.4) A

5.5) D

5.6) C

6) D

7) E

8) C

9) B

10.1) E

10.2) A

11) C

12) C

Physio #3

1) E

2) C

3.1) B

3.2) A

3.3) D

4) E

5.1) C

5.2) C

6.1) A

6.2) C

7.1) C

7.2) D

8.1) E

8.2) E

9) B

10) C

11) E

12) C

13.1) C

13.2) D

13.3) B

13.4) A

13.5) B

13.6) D

14) D

15) A

16) C

17.1) D

17.2) A

17.3) C

17.4) E

Physio #4

1) E

2.1) C

2.2) D

2.3) A

2.4) B

2.5) A

3.1) E

3.2) D

3.3) D

4) C

5.1) E

5.2) D

5.3) A

6.1) C

6.2) B

7) A

8.1) A

8.2) D

9) B

10) D

11) B

12.1) B

12.2) A

13.1) C

13.2) D

13.3) E

14) B

15.1) C

15.2) A

15.3) B

15.4) A

15.5) D

16.1) A

16.2) E

Physio #5

1) B

2) A

3) E

4) C

5) C

6.1) E

6.2) C

7) B

8) D

9) A

10) C

11) B

12) E

13) D

14) A

15) C

16.1) B

16.2) B

17) B

18) D

19) E

20.1) A

20.2) C

21) A

22) E

23) D

24) B

25) D

26.1) C

26.2) D

27) B

28) E

29) D

30.1) B

30.2) A

31) C

32) A

33) E

34.1) E

34.2) D

Physio #6

1.1) B

1.2) C

1.3) A

1.4) A

1.5) C



1.6) A

1.7) E

2.1) D

2.2) C

3) B

4.1) C

4.2) C

4.3) D

4.4) A

4.5) C

4.6) D

5.1) B

5.2) E

5.3) B

5.4) C

5.5) A

6.1) C

6.2) D

6.3) A

6.4) B

7.1) C

7.2) B

7.3) E

8.1) B

8.2) D

9.1) E

9.2) C

9.3) C

9.4) A

9.5) C

9.6) D

10.1) D

10.2) A

10.3) E

11) E

12) B

13.1) C

13.2) B

14.1) B

14.2) E

14.3) D

15) D

16) D

17.1) B

17.2) A

18) C

19) E

20) B

21.1) C

21.2) B

21.3) D

22) A

23.1) D

23.2) E

24.1) C

24.2) C

24.3) D

25) A

26.1) B

26.2) D

26.3) B

26.5) E

27.1) C

27.2) A

27.3) D

28.1) B

28.2) B

Physio #7

1) E

2) C

3.1) E

3.2) D

4) A

5) B

6.1) C

6.2) E

7) D

8) C

9) A

10) B

11) A

12) C

Physio #8

1) D

2.1) B

2.2) C

2.3) A

2.4) E

2.5) D

2.6) B

2.7) C

2.8) A

2.9) C

2.10) A

2.11) D

2.12) B

2.13) C

3) C

4) E

5) E

6.1) A

6.2) B

6.3) D

6.4) A

6.5) D

6.6) C

7) A

8) E

9.1) B

9.2) E

10.1) D

10.2) B

11) C

12) B

13) A

14) C

15) E

16.1) D

16.2) B

16.3) C

Physio #9

1) E

2) C

3) B

4) B

5) D

6.1) B

6.2) A

6.3) C

6.4) A

6.5) B

7) C

8.1) E

8.2) B

9) C

10) E

11) D

12) C

13.1) C

13.2) D

14.1) D

14.2) C

Quiz Physiology

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