NU-362 - PATHO EXAM 1 QUESTIONS
AND ANSWERS
Capillary (plasma) oncotic pressure: - Answer-osmotically attracts water from the
interstitial space back into the capillary.
Interstitial hydrostatic pressure: - Answer-facilitates the inward movement of water from
the interstitial space into the capillary.
Interstitial oncotic pressure: - Answer-osmotically attracts water from the capillary into
the interstitial space.
aquaporins are: - Answer-a family of water channel proteins that provide permeability to
water.
The four main causes of Edema are: - Answer-1)Increased Capillary Permeability.
2)Decreased Capillary Oncotic Pressure.
3)Lymphatic Obstruction.
4)Increased Capillary Hydrostatic Pressure.
How does a decrease in capillary oncotic pressure cause edema? - Answer-Lost or
diminished plasma albumin production contributes to decreased plasma oncotic
pressure. The decreased oncotic attraction of fluid within the capillaries causes capillary
fluid to move into the interstitial space, resulting in edema.
What forces promote net filtration? - Answer-The net filtration of fluid, or the movement
of water back and forth across capillary membranes, is controlled by capillary and
interstitial hydrostatic and oncotic pressures (Starling forces). Forces favoring
movement of water from capillaries to interstitium are relative increases in capillary
hydrostatic pressure and interstitial hydrostatic pressure.
What hormones regulate salt and water balance - Answer-Primarily Antidiuretic
hormone (ADH). When the serum osmolarity is elevated, ADH is released by the
posterior pituitary gland and causes water to be reabsorbed into the blood from the
distal tubules and collecting ducts of the kidneys. Sodium serum level is regulated
primarily by aldosterone from the adrenal cortex, which causes the kidneys to reabsorb
both sodium and water when the extracellular fluid level or the sodium level is low. In
addition, natriuretic hormones are released in response to an increase in blood volume
or blood pressure and act to increase sodium and water excretion.
How does an increase in capillary hydrostatic pressure cause edema? - Answer-
Hydrostatic pressure increases as a result of venous obstruction or salt and water
retention. Venous obstruction causes hydrostatic pressure to increase behind the
, obstruction, pushing fluid out of the capillaries and into the interstitial spaces, thereby
causing edema.
What causes isotonic imbalance? - Answer-Changes in the isotonic (normal) sodium
and water balances of the body can be caused by a gain or loss of extracellular fluid
(ECF) or sodium that changes the normal 0.9% salt solution of the body fluids.
Hypertonic imbalances result when water is lost or sodium gained. Hypotonic
imbalances result when water is gained or sodium lost.
What is a hypotonic imbalance? Give two examples. - Answer-Hypotonic imbalance can
be caused by a decrease in serum sodium levels as a result of factors such as diuresis
or profuse sweating. In diuresis, sodium is lost through excessive excretion by the
kidneys. In sweating, sodium is lost through the skin. Hypotonic imbalance also can be
caused by excessive oral or intravenous (IV) water intake or by a decrease in water
excretion (as can occur in renal failure).
What role does potassium play in the body? What metabolic dysfunctions occur in
potassium deficiency? In potassium excess? - Answer-Potassium facilitates glycogen
deposition in the liver and skeletal muscles. It maintains the resting membrane
potentials of cells, which is important for normal nerve conduction; cardiac rhythm; and
skeletal, smooth, and cardiac muscle contraction.
In hypokalemia (potassium deficiency). - Answer-1) carbohydrate metabolism is
affected because insulin secretion is depressed and muscle and liver glycogen
synthesis is reduced;
2) metabolic alkalosis can occur because, as potassium moves from the intracellular
fluid (ICF) to the ECF, hydrogen ions move into the cells to maintain cation balance;
3) polyuria and volume depletion can occur because decreased potassium levels impair
renal function, resulting in a decreased ability of the kidneys to respond to ADH and to
concentrate urine; and
4) skeletal, smooth, and cardiac muscle weakness and cardiac dysrhythmias can occur
because low potassium levels decrease neuromuscular and cardiac excitability.
In hyperkalemia (potassium excess). - Answer-1) skeletal, smooth, and cardiac muscle
excitability is increased;
2) cardiac dysrhythmias such as heart block and cardiac arrest can occur;
3) metabolic acidosis can occur as potassium moves from the ECF into the cells and
intracellular and hydrogen ions move out of the cells and into the ECF; and
4) renal function is affected, resulting in fluid retention and oliguria.
How can you NOT have a deficiency in total body potassium and still have
hypokalemia? - Answer-ECF hypokalemia can develop without loss of total body
potassium. Potassium shifts into the cells during respiratory or metabolic acidosis or
after administration of insulin. In alkalosis, potassium shifts into the cell in exchange for
hydrogen ions to maintain plasma acid-base balance. Insulin also promotes cellular
uptake of potassium, causing an ECF potassium deficit.
AND ANSWERS
Capillary (plasma) oncotic pressure: - Answer-osmotically attracts water from the
interstitial space back into the capillary.
Interstitial hydrostatic pressure: - Answer-facilitates the inward movement of water from
the interstitial space into the capillary.
Interstitial oncotic pressure: - Answer-osmotically attracts water from the capillary into
the interstitial space.
aquaporins are: - Answer-a family of water channel proteins that provide permeability to
water.
The four main causes of Edema are: - Answer-1)Increased Capillary Permeability.
2)Decreased Capillary Oncotic Pressure.
3)Lymphatic Obstruction.
4)Increased Capillary Hydrostatic Pressure.
How does a decrease in capillary oncotic pressure cause edema? - Answer-Lost or
diminished plasma albumin production contributes to decreased plasma oncotic
pressure. The decreased oncotic attraction of fluid within the capillaries causes capillary
fluid to move into the interstitial space, resulting in edema.
What forces promote net filtration? - Answer-The net filtration of fluid, or the movement
of water back and forth across capillary membranes, is controlled by capillary and
interstitial hydrostatic and oncotic pressures (Starling forces). Forces favoring
movement of water from capillaries to interstitium are relative increases in capillary
hydrostatic pressure and interstitial hydrostatic pressure.
What hormones regulate salt and water balance - Answer-Primarily Antidiuretic
hormone (ADH). When the serum osmolarity is elevated, ADH is released by the
posterior pituitary gland and causes water to be reabsorbed into the blood from the
distal tubules and collecting ducts of the kidneys. Sodium serum level is regulated
primarily by aldosterone from the adrenal cortex, which causes the kidneys to reabsorb
both sodium and water when the extracellular fluid level or the sodium level is low. In
addition, natriuretic hormones are released in response to an increase in blood volume
or blood pressure and act to increase sodium and water excretion.
How does an increase in capillary hydrostatic pressure cause edema? - Answer-
Hydrostatic pressure increases as a result of venous obstruction or salt and water
retention. Venous obstruction causes hydrostatic pressure to increase behind the
, obstruction, pushing fluid out of the capillaries and into the interstitial spaces, thereby
causing edema.
What causes isotonic imbalance? - Answer-Changes in the isotonic (normal) sodium
and water balances of the body can be caused by a gain or loss of extracellular fluid
(ECF) or sodium that changes the normal 0.9% salt solution of the body fluids.
Hypertonic imbalances result when water is lost or sodium gained. Hypotonic
imbalances result when water is gained or sodium lost.
What is a hypotonic imbalance? Give two examples. - Answer-Hypotonic imbalance can
be caused by a decrease in serum sodium levels as a result of factors such as diuresis
or profuse sweating. In diuresis, sodium is lost through excessive excretion by the
kidneys. In sweating, sodium is lost through the skin. Hypotonic imbalance also can be
caused by excessive oral or intravenous (IV) water intake or by a decrease in water
excretion (as can occur in renal failure).
What role does potassium play in the body? What metabolic dysfunctions occur in
potassium deficiency? In potassium excess? - Answer-Potassium facilitates glycogen
deposition in the liver and skeletal muscles. It maintains the resting membrane
potentials of cells, which is important for normal nerve conduction; cardiac rhythm; and
skeletal, smooth, and cardiac muscle contraction.
In hypokalemia (potassium deficiency). - Answer-1) carbohydrate metabolism is
affected because insulin secretion is depressed and muscle and liver glycogen
synthesis is reduced;
2) metabolic alkalosis can occur because, as potassium moves from the intracellular
fluid (ICF) to the ECF, hydrogen ions move into the cells to maintain cation balance;
3) polyuria and volume depletion can occur because decreased potassium levels impair
renal function, resulting in a decreased ability of the kidneys to respond to ADH and to
concentrate urine; and
4) skeletal, smooth, and cardiac muscle weakness and cardiac dysrhythmias can occur
because low potassium levels decrease neuromuscular and cardiac excitability.
In hyperkalemia (potassium excess). - Answer-1) skeletal, smooth, and cardiac muscle
excitability is increased;
2) cardiac dysrhythmias such as heart block and cardiac arrest can occur;
3) metabolic acidosis can occur as potassium moves from the ECF into the cells and
intracellular and hydrogen ions move out of the cells and into the ECF; and
4) renal function is affected, resulting in fluid retention and oliguria.
How can you NOT have a deficiency in total body potassium and still have
hypokalemia? - Answer-ECF hypokalemia can develop without loss of total body
potassium. Potassium shifts into the cells during respiratory or metabolic acidosis or
after administration of insulin. In alkalosis, potassium shifts into the cell in exchange for
hydrogen ions to maintain plasma acid-base balance. Insulin also promotes cellular
uptake of potassium, causing an ECF potassium deficit.
