NURS 5315 ADVANCED PATHO EXAM QUESTIONS
AND ANSWERS A+ GRADED
Steps of the Action Potential
Depolarization
Repolarization
Hyperpolarization
Depolarization
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
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
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
t has to depolarize by 15-20 mV (threshold potential) to reach -55 to -65 mV.
An alteration in action potential may result from
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.
Na+-K+ ATPase
Resting membrane potential
when the cell is in a nonexcited state and is at -70 to -85 mV.
Refractory Period
is a period of time during most of the action potential which the cell membrane resists
stimulation and it cannot depolarize
Absolute refractory period
occurs when the membrane will not respond to ANY stimulus no matter how strong.
Relative Refractory Period
occurs when the membrane is repolarizing and will only respond to a very strong
stimulus.
Hyperpolarized
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
,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
(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
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
-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
-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
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
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
, -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
-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
dysplasia - abnormal changes in size, shape, and organization of mature cells due to
persistent, severe cell injury or irritation
Metaplasia
-reversible change in which one adult cell is replaced by another adult cell
-Etiology: found in tissue damage, repair, and regeneration
-Results from the exposure of the cells to chronic stressors, injury, or irritation. If the
influences that cause the cellular changes remain present, they can induce a malignant
change in the cells
-Ex: most common is the change from columnar cells to squamous cells - this occurs in
chronic smokers or gastroesophageal reflux (GERD)
Physiologic Example of Hyperplasia
-Occurs when there is an increase in tissue mass after damage or partial resection,
allowing the organ to regenerate
Ex - removal of part of the liver and the cells regenerating, uterine and mammary gland
enlargement occur during pregnancy to meet the demands of the increased work load,
callus on foot
Ex: (Hormonal) Breast and uterine enlargement during pregnancy.
Pathological Example of Hyperplasia
-Is an abnormal proliferation of normal cells usually caused by increased hormonal
stimulation
Ex - endometrial hyperplasia (imbalnce in estrogen & progesterone with increase in
estrogen - risk for cancer), Benign prostatic hyperplasia (BPH), thyroid enlargement -
thyroid goiters
Pathological Example of Hypertrophy
left ventricular hypertrophy
cardiomegaly
Physiological Example of Hypertrophy
Skeletal muscle, when a kidney is removed and the other kidney steps in to function as
both and increases in size
Physiological Example of Atrophy
Shrinking of the thymus gland during childhood, uterus decreasing in size after childbirth
Disuse - skeletal muscle atrophy that occurs from a person being immobilized or bed
ridden for a period of time
(arm in a cast,
AND ANSWERS A+ GRADED
Steps of the Action Potential
Depolarization
Repolarization
Hyperpolarization
Depolarization
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
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
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
t has to depolarize by 15-20 mV (threshold potential) to reach -55 to -65 mV.
An alteration in action potential may result from
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.
Na+-K+ ATPase
Resting membrane potential
when the cell is in a nonexcited state and is at -70 to -85 mV.
Refractory Period
is a period of time during most of the action potential which the cell membrane resists
stimulation and it cannot depolarize
Absolute refractory period
occurs when the membrane will not respond to ANY stimulus no matter how strong.
Relative Refractory Period
occurs when the membrane is repolarizing and will only respond to a very strong
stimulus.
Hyperpolarized
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
,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
(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
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
-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
-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
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
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
, -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
-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
dysplasia - abnormal changes in size, shape, and organization of mature cells due to
persistent, severe cell injury or irritation
Metaplasia
-reversible change in which one adult cell is replaced by another adult cell
-Etiology: found in tissue damage, repair, and regeneration
-Results from the exposure of the cells to chronic stressors, injury, or irritation. If the
influences that cause the cellular changes remain present, they can induce a malignant
change in the cells
-Ex: most common is the change from columnar cells to squamous cells - this occurs in
chronic smokers or gastroesophageal reflux (GERD)
Physiologic Example of Hyperplasia
-Occurs when there is an increase in tissue mass after damage or partial resection,
allowing the organ to regenerate
Ex - removal of part of the liver and the cells regenerating, uterine and mammary gland
enlargement occur during pregnancy to meet the demands of the increased work load,
callus on foot
Ex: (Hormonal) Breast and uterine enlargement during pregnancy.
Pathological Example of Hyperplasia
-Is an abnormal proliferation of normal cells usually caused by increased hormonal
stimulation
Ex - endometrial hyperplasia (imbalnce in estrogen & progesterone with increase in
estrogen - risk for cancer), Benign prostatic hyperplasia (BPH), thyroid enlargement -
thyroid goiters
Pathological Example of Hypertrophy
left ventricular hypertrophy
cardiomegaly
Physiological Example of Hypertrophy
Skeletal muscle, when a kidney is removed and the other kidney steps in to function as
both and increases in size
Physiological Example of Atrophy
Shrinking of the thymus gland during childhood, uterus decreasing in size after childbirth
Disuse - skeletal muscle atrophy that occurs from a person being immobilized or bed
ridden for a period of time
(arm in a cast,
