GMS-6440 Medical Physiology Exam 1
Questions and Answers
What chemical component of the plasma membrane prevents ions from readily and
freely moving across the membrane? - Answer-Lipids (phospholipids)
Where is the concentration of [K+] greater? - Answer-In the cytoplasm
Across a cell's plasma membrane, movemen of water is a ___________ event. -
Answer-Passive through a channel.
Where is the concentration of [Na+] greater? - Answer-In the extracellular fluid.
For a neutrally charged molecule, "Active" transport means the molecules move
across a membrane from? - Answer-A low concentration to a higher concentration.
What molecule is the source of energy for primary active transport to occur? -
Answer-ATP (adenosine triphosphate)
True of False: There is only one type of channel in cell membranes. - Answer-False.
True or False: Regarding primary active transport, solutes move from a compartment
of low concentration to a compartment of high concentration. - Answer-True. Always
low to high.
True or False: Regarding secondary active transport of glucose, the movement of
glucose is from a compartment of high concentration to a compartment of low
concentration. - Answer-False.
True or False: All transport through membrane channels is classified "Active"
transport. - Answer-False.
True or False: Electrolytes are pumped and leaked across cell membranes
simultaneously but independently. - Answer-True.
At what point in time does the electrochemical equilibrium potential exist? - Answer-
At equilibrium.
What major factor that regulates an electrolyte's electrochemical equilibrium potential
across a cell membrane? - Answer-Concentration (chemical) gradient.
True or False: The electrochemical equilibrium potential for a single highly permant
ion species is controlled by the concentration gradient. - Answer-True.
True or False: Movement of a charge electrolyte is determined by the major forces of
voltage plus chemical concentration gradients. - Answer-True.
,True or False: The cellular K+ Electrochemical Equilibrium Potential is regulated by
concentration differences across the plasma membranes. - Answer-True.
Which of these ion choices is primarily responsible for establishing a typical cell
membrane's resting potential?
A. Mg++
B. Na+
C. K+ - Answer-K+
True or False: Excessive extracellular acid (i.e. [H+]) will raise the concentration of
extracellular potassium ion concentration. - Answer-True.
True or False: Cell Membrane Potential is controlled by the relative degree of ion
permeability as well as ion concentration gradients existing across a cell's plasma
membrane. - Answer-True.
True or False: Rhabdomyolysis can lead to cardiac muscle cell pathology as the
result of creating a condition of hyperkalemia (excessive K+ concentration in the
plasma). - Answer-True.
True or False: A normal lean person consists of 90% water. - Answer-False, 60%
water.
True or False: Most of the sodium in the body is inside the cells. - Answer-False, it is
extracellular. K+ is intracellular.
True or False: The capillary is the main barrier between the intracellular and
extracellular fluids. - Answer-False. The cell wall, also called the plasma membrane,
separates ICF and ECF. The capillary separates the interstitium and the plasma
which are both subcompartments of the ECF.
True or False: To measure the volume of the entire extracellular fluid compartment,
we use a substance that moves freely across the capillary but cannot enter the cell. -
Answer-True. An example is insulin.
True or False: Water and small solutes move across the capillary wall by active
transport. - Answer-False. All movement across the capillary wall is PASSIVE.
Driven only by hydrostatic and colloid osmotic (oncotic) pressures.
True or False: The osmolality of the body fluids is greater when all the solutes are
large. - Answer-False. The total number of particles, irrespective of size, determines
the osmolality.
True or False: All water movement in and out of cell is passive. - Answer-True. All
water movement is driven by solute (osmotic) gradients across the cell wall.
True or False: Sodium (Na) is effectively impermeable at the cell wall. - Answer-
True. Any Na that does enter the cell will be immediately removed by the Sodium
Potassium ATPase in the cell wall.
, True or False: Eating a meal high in salt, without drinking any water, will lead to an
increase in both intracellular and extracellular fluid volume. - Answer-False. This is
HYPERTONIC expansion. Ingested NaCl stays extracellular, increases the ECF
osmolality, H2O moves OUT fo cells to restore osmotic equilibrium. Decrease in
ICFV, increase in ECFV.
True or False: A pure water solution can safely be infused intravenously to a
dehydrated person. - Answer-False.
True or False. Hormones produce physiological actions by binding to receptors at
their target cells/tissues. - Answer-True.
True or False. There are specific receptors for each hormone. - Answer-True.
True or False. Receptors for peptide hormones are always on the inside (cytoplasm;
nucleus) of target cells. - Answer-False.
True or False. GPCR are also known as seven trans-membrane (7TM) receptors. -
Answer-True.
True or False. Gaq proteins couple to adenylyl cyclase. - Answer-False.
True or False. Activation of ionotropic receptors results in an ion (Ca2+; Na+) moving
into the target cell through a channel in the receptor. - Answer-True.
True or False. Ionotropic receptors signal via G proteins. - Answer-False.
True or False. Receptor Guanylyl Cyclases are one type of Catalytic Receptor. -
Answer-True.
True or False. Receptors of Thyroid Hormone and steroids are always on the surface
(plasma membrane) of target cells. - Answer-False.
True or False. Dimerization is important for some catalytic receptors, but never for
steroid hormone receptors. - Answer-False.
True or False. The nervous system is usually divided into 3 anatomical components.
- Answer-False.
True or False. Glia are only present in the central nervous system. - Answer-False.
True or False. The Nucleus of the Solitary Tract is in the medulla oblongata. -
Answer-True.
True or False. The hypothalamus regulates both autonomic and endocrine function. -
Answer-True.
True or False. Afferent nerves transmit information from the central nervous system
to the peripheral nervous system. - Answer-False.
Questions and Answers
What chemical component of the plasma membrane prevents ions from readily and
freely moving across the membrane? - Answer-Lipids (phospholipids)
Where is the concentration of [K+] greater? - Answer-In the cytoplasm
Across a cell's plasma membrane, movemen of water is a ___________ event. -
Answer-Passive through a channel.
Where is the concentration of [Na+] greater? - Answer-In the extracellular fluid.
For a neutrally charged molecule, "Active" transport means the molecules move
across a membrane from? - Answer-A low concentration to a higher concentration.
What molecule is the source of energy for primary active transport to occur? -
Answer-ATP (adenosine triphosphate)
True of False: There is only one type of channel in cell membranes. - Answer-False.
True or False: Regarding primary active transport, solutes move from a compartment
of low concentration to a compartment of high concentration. - Answer-True. Always
low to high.
True or False: Regarding secondary active transport of glucose, the movement of
glucose is from a compartment of high concentration to a compartment of low
concentration. - Answer-False.
True or False: All transport through membrane channels is classified "Active"
transport. - Answer-False.
True or False: Electrolytes are pumped and leaked across cell membranes
simultaneously but independently. - Answer-True.
At what point in time does the electrochemical equilibrium potential exist? - Answer-
At equilibrium.
What major factor that regulates an electrolyte's electrochemical equilibrium potential
across a cell membrane? - Answer-Concentration (chemical) gradient.
True or False: The electrochemical equilibrium potential for a single highly permant
ion species is controlled by the concentration gradient. - Answer-True.
True or False: Movement of a charge electrolyte is determined by the major forces of
voltage plus chemical concentration gradients. - Answer-True.
,True or False: The cellular K+ Electrochemical Equilibrium Potential is regulated by
concentration differences across the plasma membranes. - Answer-True.
Which of these ion choices is primarily responsible for establishing a typical cell
membrane's resting potential?
A. Mg++
B. Na+
C. K+ - Answer-K+
True or False: Excessive extracellular acid (i.e. [H+]) will raise the concentration of
extracellular potassium ion concentration. - Answer-True.
True or False: Cell Membrane Potential is controlled by the relative degree of ion
permeability as well as ion concentration gradients existing across a cell's plasma
membrane. - Answer-True.
True or False: Rhabdomyolysis can lead to cardiac muscle cell pathology as the
result of creating a condition of hyperkalemia (excessive K+ concentration in the
plasma). - Answer-True.
True or False: A normal lean person consists of 90% water. - Answer-False, 60%
water.
True or False: Most of the sodium in the body is inside the cells. - Answer-False, it is
extracellular. K+ is intracellular.
True or False: The capillary is the main barrier between the intracellular and
extracellular fluids. - Answer-False. The cell wall, also called the plasma membrane,
separates ICF and ECF. The capillary separates the interstitium and the plasma
which are both subcompartments of the ECF.
True or False: To measure the volume of the entire extracellular fluid compartment,
we use a substance that moves freely across the capillary but cannot enter the cell. -
Answer-True. An example is insulin.
True or False: Water and small solutes move across the capillary wall by active
transport. - Answer-False. All movement across the capillary wall is PASSIVE.
Driven only by hydrostatic and colloid osmotic (oncotic) pressures.
True or False: The osmolality of the body fluids is greater when all the solutes are
large. - Answer-False. The total number of particles, irrespective of size, determines
the osmolality.
True or False: All water movement in and out of cell is passive. - Answer-True. All
water movement is driven by solute (osmotic) gradients across the cell wall.
True or False: Sodium (Na) is effectively impermeable at the cell wall. - Answer-
True. Any Na that does enter the cell will be immediately removed by the Sodium
Potassium ATPase in the cell wall.
, True or False: Eating a meal high in salt, without drinking any water, will lead to an
increase in both intracellular and extracellular fluid volume. - Answer-False. This is
HYPERTONIC expansion. Ingested NaCl stays extracellular, increases the ECF
osmolality, H2O moves OUT fo cells to restore osmotic equilibrium. Decrease in
ICFV, increase in ECFV.
True or False: A pure water solution can safely be infused intravenously to a
dehydrated person. - Answer-False.
True or False. Hormones produce physiological actions by binding to receptors at
their target cells/tissues. - Answer-True.
True or False. There are specific receptors for each hormone. - Answer-True.
True or False. Receptors for peptide hormones are always on the inside (cytoplasm;
nucleus) of target cells. - Answer-False.
True or False. GPCR are also known as seven trans-membrane (7TM) receptors. -
Answer-True.
True or False. Gaq proteins couple to adenylyl cyclase. - Answer-False.
True or False. Activation of ionotropic receptors results in an ion (Ca2+; Na+) moving
into the target cell through a channel in the receptor. - Answer-True.
True or False. Ionotropic receptors signal via G proteins. - Answer-False.
True or False. Receptor Guanylyl Cyclases are one type of Catalytic Receptor. -
Answer-True.
True or False. Receptors of Thyroid Hormone and steroids are always on the surface
(plasma membrane) of target cells. - Answer-False.
True or False. Dimerization is important for some catalytic receptors, but never for
steroid hormone receptors. - Answer-False.
True or False. The nervous system is usually divided into 3 anatomical components.
- Answer-False.
True or False. Glia are only present in the central nervous system. - Answer-False.
True or False. The Nucleus of the Solitary Tract is in the medulla oblongata. -
Answer-True.
True or False. The hypothalamus regulates both autonomic and endocrine function. -
Answer-True.
True or False. Afferent nerves transmit information from the central nervous system
to the peripheral nervous system. - Answer-False.
