NURS 5315 Advanced Patho Exam 1
UPDATED Questions and CORRECT
Answers
Steps of the Action Potential - CORRECT ANSWER - Depolarization
Repolarization
Hyperpolarization
Depolarization - CORRECT ANSWER - movement of the intracellular charge towards
zero (more positive charge)
Voltage gated Na channels open and allow Na to enter the cell -> voltage inside the cell moves
towards zero
Repolarization - CORRECT ANSWER - Once the intracellular charge reaches zero, the
negative polarity of the inside of the cell is restored back to its baseline of -70 to -85 mV
-Na channels close, K channels open
Hyperpolarization - CORRECT ANSWER - when the cell's resting membrane potential is
greater than -85mV. Is less excitable, because there is a greater distance between the resting
membrane potential and the threshold potential.
In order for the action potential to be sucessful - CORRECT ANSWER - t has to
depolarize by 15-20 mV (threshold potential) to reach -55 to -65 mV.
An alteration in action potential may result from - CORRECT ANSWER - neurologic
diseases, muscle disease or electrolyte imbalances.
,What is the main protein responsible for maintaining the correct balance of extracellular Na and
intracellular K, which is needed for cellular excitation and membrane conductivity. - CORRECT
ANSWER - Na+-K+ ATPase
Resting membrane potential - CORRECT ANSWER - when the cell is in a nonexcited
state and is at -70 to -85 mV.
Refractory Period - CORRECT ANSWER - is a period of time during most of the action
potential which the cell membrane resists stimulation and it cannot depolarize
Absolute refractory period - CORRECT ANSWER - occurs when the membrane will not
respond to ANY stimulus no matter how strong.
Relative Refractory Period - CORRECT ANSWER - occurs when the membrane is
repolarizing and will only respond to a very strong stimulus.
Hyperpolarized - CORRECT ANSWER - when the cell's resting membrane potential is
greater than -85mV.
Is less excitable, because there is a greater distance between the resting membrane potential and
the threshold potential.
Hypopolarized - CORRECT ANSWER - when the cell's resting membrane potential is
closer to zero, for instance it is -65mV.
Is more excitable because the resting membrane potential is closer to the threshold potential,
there is less distance between them.
Action potential altered by hypokalemia - CORRECT ANSWER - (serum outside of cell is
low)
-Hyperpolarized (cell becomes more negative, ex: -100)
-Affects the resting membrane potential of cells
-The cell is less likely to depolarize and transmit impulses
, Can cause a decrease in neuromuscular excitability and leads to weakness, smooth muscle atony,
paresthesias, and cardiac dysrhythmias
Action potential altered by hyperkalemia - CORRECT ANSWER - Hypopolarized
-Also has an effect on the resting membrane potential
-If the ECF potassium increases without any change in the ICF potassium levels, the resting
membrane potential of the cell becomes more positive.
-The cells are more excitable and conduct impulses more easily and more quickly because the
resting membrane potential is closer to the threshold potential. Therefore, the person will have
peak T waves on EKG.
-As potassium rises, the resting membrane potential will continue to become more positive and it
will eventually become equal to the threshold potential. As this happens the EKG will show a
widening QRS complex. If the resting membrane potential equals the threshold potential, an
action potential will not be generated and cardiac standstill will occur. Paralysis and paresthesias
may also occur.
Action potential altered by hypocalcemia - CORRECT ANSWER - -Causes an increase in
the cell permeability to Na causing a progressive depolarization
-Causes the RMP and the TP to be closer to one another & making it easier to initiate an action
potential - the cells are more excitable.
-Results in tetany, hyperreflexia, circumoral paresthesias, seizures, dysrhythmias
Action potential altered by hypercalcemia - CORRECT ANSWER - -Causes a decrease in
cell permeability to Na
-Causes the RMP and the TP to increase in distance - the cells are less excitable and requires
more of a stimulus to initiate an action potential.
-Leads to weakness, hyporeflexia, fatigue, lethargy, confusion, encephalopathy, a shortened QT
segment and depressed widened T waves on EKG.
Atrophy - CORRECT ANSWER - decrease or shrinkage in the size of the cell
-Imbalance between protein synthesis and degradation, , reduction of the intracellular contents,
also includes a self-eating process called autophagy.
-Example: aging brain cells, malnutrition, uterus decreasing in size after childbirth
UPDATED Questions and CORRECT
Answers
Steps of the Action Potential - CORRECT ANSWER - Depolarization
Repolarization
Hyperpolarization
Depolarization - CORRECT ANSWER - movement of the intracellular charge towards
zero (more positive charge)
Voltage gated Na channels open and allow Na to enter the cell -> voltage inside the cell moves
towards zero
Repolarization - CORRECT ANSWER - Once the intracellular charge reaches zero, the
negative polarity of the inside of the cell is restored back to its baseline of -70 to -85 mV
-Na channels close, K channels open
Hyperpolarization - CORRECT ANSWER - when the cell's resting membrane potential is
greater than -85mV. Is less excitable, because there is a greater distance between the resting
membrane potential and the threshold potential.
In order for the action potential to be sucessful - CORRECT ANSWER - t has to
depolarize by 15-20 mV (threshold potential) to reach -55 to -65 mV.
An alteration in action potential may result from - CORRECT ANSWER - neurologic
diseases, muscle disease or electrolyte imbalances.
,What is the main protein responsible for maintaining the correct balance of extracellular Na and
intracellular K, which is needed for cellular excitation and membrane conductivity. - CORRECT
ANSWER - Na+-K+ ATPase
Resting membrane potential - CORRECT ANSWER - when the cell is in a nonexcited
state and is at -70 to -85 mV.
Refractory Period - CORRECT ANSWER - is a period of time during most of the action
potential which the cell membrane resists stimulation and it cannot depolarize
Absolute refractory period - CORRECT ANSWER - occurs when the membrane will not
respond to ANY stimulus no matter how strong.
Relative Refractory Period - CORRECT ANSWER - occurs when the membrane is
repolarizing and will only respond to a very strong stimulus.
Hyperpolarized - CORRECT ANSWER - when the cell's resting membrane potential is
greater than -85mV.
Is less excitable, because there is a greater distance between the resting membrane potential and
the threshold potential.
Hypopolarized - CORRECT ANSWER - when the cell's resting membrane potential is
closer to zero, for instance it is -65mV.
Is more excitable because the resting membrane potential is closer to the threshold potential,
there is less distance between them.
Action potential altered by hypokalemia - CORRECT ANSWER - (serum outside of cell is
low)
-Hyperpolarized (cell becomes more negative, ex: -100)
-Affects the resting membrane potential of cells
-The cell is less likely to depolarize and transmit impulses
, Can cause a decrease in neuromuscular excitability and leads to weakness, smooth muscle atony,
paresthesias, and cardiac dysrhythmias
Action potential altered by hyperkalemia - CORRECT ANSWER - Hypopolarized
-Also has an effect on the resting membrane potential
-If the ECF potassium increases without any change in the ICF potassium levels, the resting
membrane potential of the cell becomes more positive.
-The cells are more excitable and conduct impulses more easily and more quickly because the
resting membrane potential is closer to the threshold potential. Therefore, the person will have
peak T waves on EKG.
-As potassium rises, the resting membrane potential will continue to become more positive and it
will eventually become equal to the threshold potential. As this happens the EKG will show a
widening QRS complex. If the resting membrane potential equals the threshold potential, an
action potential will not be generated and cardiac standstill will occur. Paralysis and paresthesias
may also occur.
Action potential altered by hypocalcemia - CORRECT ANSWER - -Causes an increase in
the cell permeability to Na causing a progressive depolarization
-Causes the RMP and the TP to be closer to one another & making it easier to initiate an action
potential - the cells are more excitable.
-Results in tetany, hyperreflexia, circumoral paresthesias, seizures, dysrhythmias
Action potential altered by hypercalcemia - CORRECT ANSWER - -Causes a decrease in
cell permeability to Na
-Causes the RMP and the TP to increase in distance - the cells are less excitable and requires
more of a stimulus to initiate an action potential.
-Leads to weakness, hyporeflexia, fatigue, lethargy, confusion, encephalopathy, a shortened QT
segment and depressed widened T waves on EKG.
Atrophy - CORRECT ANSWER - decrease or shrinkage in the size of the cell
-Imbalance between protein synthesis and degradation, , reduction of the intracellular contents,
also includes a self-eating process called autophagy.
-Example: aging brain cells, malnutrition, uterus decreasing in size after childbirth
