NURS 5315 ADVANCED PATHOPHYSIOLOGY EXAM 1 | QUESTIONS
AND ANSWERS | VERIFIED ANSWERS GRADED A+ | LATEST EXAM
UPDATE
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
Hypertrophy - CORRECT ANSWER - increase in the size of cells, which
ultimately increases the size of the organ
-Etiology: triggers include repetitive stretching, chronic pressure, volume
overload
-Pathophysiology: hormonal stimulation or increased functional demand, which
increases the cellular protein in the plasma membrane, endoplasmic reticulum,
myofilaments, and mitochondria
Hyperplasia - CORRECT ANSWER - -increase in number of cells, not the size
of the cell, which results from an increased rate of cell division, it can only
happen in cells that are capable of mitosis *
-Etiology: results from the production of growth factors which stimulate cells to
produce new cellular contents and divide
Dysplasia - CORRECT ANSWER - -abnormal changes in the size, shape, and
organization of mature cells due to persistent, severe cell injury or irritation
-Disordered cell growth and is mainly found in epithelial tissue of the uterine
cervix, the endometrium, GI and respiratory tract mucosa,
-Ex: pap smears often show dysplastic cells of the cervix, uterine cells
Referred to as atypical hyperplasia - CORRECT ANSWER - dysplasia -
abnormal changes in size, shape, and organization of mature cells due to
persistent, severe cell injury or irritation
AND ANSWERS | VERIFIED ANSWERS GRADED A+ | LATEST EXAM
UPDATE
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
Hypertrophy - CORRECT ANSWER - increase in the size of cells, which
ultimately increases the size of the organ
-Etiology: triggers include repetitive stretching, chronic pressure, volume
overload
-Pathophysiology: hormonal stimulation or increased functional demand, which
increases the cellular protein in the plasma membrane, endoplasmic reticulum,
myofilaments, and mitochondria
Hyperplasia - CORRECT ANSWER - -increase in number of cells, not the size
of the cell, which results from an increased rate of cell division, it can only
happen in cells that are capable of mitosis *
-Etiology: results from the production of growth factors which stimulate cells to
produce new cellular contents and divide
Dysplasia - CORRECT ANSWER - -abnormal changes in the size, shape, and
organization of mature cells due to persistent, severe cell injury or irritation
-Disordered cell growth and is mainly found in epithelial tissue of the uterine
cervix, the endometrium, GI and respiratory tract mucosa,
-Ex: pap smears often show dysplastic cells of the cervix, uterine cells
Referred to as atypical hyperplasia - CORRECT ANSWER - dysplasia -
abnormal changes in size, shape, and organization of mature cells due to
persistent, severe cell injury or irritation
