Ch. 3: The Cellular Environment: Fluids, Electrolytes, Acids and Bases Flashcards
Which of the following statements is TRUE?
Two thirds of the body’s water is intracellular.
One fourth of the body’s fluid is extracellular.
The two main extracellular compartments are interstitial and intracellular.
Standard total body water is 40% of body weight.
Two thirds of the body’s water is intracellular
Two thirds of the body’s water is intracellular. One third is extracellular. There are two components of the extracellular compartment: interstitial and intravascular. Total body water is about 60% of body weight.
Which of the following statements is TRUE?
Potassium is the most abundant ECF ion.
Sodium maintains the osmotic balance of the ICF space.
Water moves freely across membranes.
Aquaporins block water movement across the membrane.
Water moves freely across membranes
Water moves freely across the capillary or cell membrane. Aquaporins are a family of water channel proteins that provide permeability to water at the capillary membrane. Sodium is the major ECF cation, and potassium is the major ICF cation; this is due to the sodium-potassium pump.
Which of the following is NOT one of the four most common causes of edema formation (increased filtration of fluid from capillaries and lymph into surrounding tissues)?
Decreased hydrostatic pressure
Decreased plasma oncotic pressure
Increased capillary membrane permeability
Lymphatic obstruction
Decreased hydrostatic pressure
There are four common causes of increased edema: increased hydrostatic pressure, decreased plasma oncotic pressure, increased capillary membrane permeability, and lymphatic obstruction.
Which of the following statements regarding water balance is TRUE?
The kidneys and liver have a central role in maintaining sodium and water balance.
Antidiuretic hormone (ADH) is released from the adrenal gland.
Sodium is regulated by aldosterone released from the pituitary.
Thirst is experienced when water loss is equal to approximately 2% of body weight.
Thirst is experienced when water loss is equal to approximately 2% of body weight
Thirst and secretion of ADH are the primary factors that regulate water balance. Thirst occurs with a loss of 2% of an individual’s body weight. ADH is secreted from the posterior pituitary, and sodium is regulated by aldosterone from the adrenal cortex.
Which of the following statements regarding aldosterone is TRUE?
It is a hormone that is secreted when sodium levels are depressed.
It is a hormone that is secreted when potassium levels are depressed.
Its action is to decrease the retention of sodium.
Its action is to decrease the secretion of potassium.
It is a hormone that is secreted when sodium levels are depressed
Aldosterone is a mineralocorticoid secreted from the adrenal gland (the adrenal gland is on the kidney). Aldosterone is secreted when potassium is increased or sodium is decreased. Therefore, it makes sense that aldosterone helps reabsorb sodium to increase a depleted supply. It then helps secrete potassium to help lower its elevated level.
Which of the following statements is TRUE regarding water balance?
Isotonic fluids cause increased cellular swelling.
Hypertonic fluid causes increased cellular swelling.
Hypotonic fluid causes cellular swelling.
Hypernatremia causes cellular swelling.
Hypotonic fluid causes cellular swelling
Hypotonic ECF causes intracellular water gain. When the ECF is hypotonic, water moves from the intravascular space to the interstitial space, across the cell membrane into the cell. This causes the cell to swell. An isotonic solution is equal to the plasma in concentration of solute molecules. Therefore, no net water will move because there is equilibrium. The cell size is unchanged. A hypertonic fluid has excessive solute, so water will leave the cell and move into the vascular space to help balance this excess. Water leaving the cell results in cell shrinkage. Hypernatremia can occur with an acute gain in sodium or loss of water but generally does not cause cellular swelling.
Which of the following is NOT a cause of hypernatremia (high sodium)?
Excessive free water intake
Inappropriate administration of hypertonic saline solution
Oversecretion of aldosterone
Cushing syndrome
Excessive free water intake
An excessive free water intake will actually cause hyponatremia, or low sodium. This is because excessive water will dilute the concentration of sodium in the blood. High sodium can be caused by inappropriate administration of hypertonic saline (sodium bicarbonate in cardiac arrest), oversecretion of aldosterone, and Cushing syndrome (increased secretion of ACTH).
Which of the following statements is TRUE regarding hyperchloremia?
Occurs with a deficit of sodium
Occurs with an excess of bicarbonate
Has specific symptoms such as thirst
Treatment is to treat underlying disorder
Treatment is to treat underlying disorder.
Hyperchloremia (too much chloride) is usually related to an underlying disorder and therefore treatment is centered on the underlying disorder. It usually occurs with an increase in sodium and a deficit of bicarbonate. There are normally no specific symptoms associated with this syndrome.
Which of the following is TRUE regarding hyponatremia?
Inadequate sodium intake is a common cause of hyponatremia.
It can occur with a decrease in total body water (TBW).
It never occurs with burns, vomiting, or diarrhea.
It is considered when sodium drops below 135 mEq/L.
It is considered when sodium drops below 135 mEq/L.
It can occur as a result of burns, vomiting, diarrhea, or gastrointestinal suctioning. It can also occur with an increase in TBW. Inadequate sodium intake can cause hyponatremia, but it is uncommon.
Which of the following is a TRUE statement regarding potassium balance?
Potassium is the major extracellular electrolyte.
During acidosis, potassium shifts into the cell.
Aldosterone is secreted when potassium is decreased.
Insulin causes the movement of potassium into the cell.
Insulin causes the movement of potassium into the cell.
Insulin causes movement of potassium into the cell and is one of the treatments for hyperkalemia. Potassium is the major intracellular electrolyte. During acidosis, potassium is shifted out of the cell in exchange for hydrogen ions. Aldosterone is secreted when potassium is elevated.
Which of the following statements is TRUE regarding hypokalemia?
Hypokalemia occurs when the serum level is below 135 mEq/L.
One cause of hypokalemia is diabetic ketoacidosis.
Dietary causes of low potassium are common.
Diuretics do not cause hypokalemia.
One cause of hypokalemia is diabetic ketoacidosis.
Hypokalemia is low potassium. It is often caused by diuretics. Hypokalemia is defined as serum level less than 3.5 mEq/L. Diabetic ketoacidosis does cause hypokalemia. Potassium is shifted out of the cell in exchange for hydrogen and then excreted. The serum level may remain within normal range, but then when insulin is given, potassium is shifted back into the cells and there is a deficit. Dietary losses are uncommon.
Which of the following is NOT a clinical manifestation of hypokalemia?
Carbohydrate metabolism is affected as a result of decreased insulin secretion.
Renal function is impaired.
Neuromuscular excitability is decreased.
Skeletal muscle is affected with increased contractility.
Skeletal muscle is affected with increased contractility.
Hypokalemia causes the skeletal muscle to be weak. Neuromuscular excitability is decreased. Renal function may be impaired, and renal tubular atrophy and fibrosis may occur. Carbohydrate metabolism is affected.
Which of the following is a TRUE statement regarding hyperkalemia?
Dietary excesses are common.
It often occurs in acidosis.
Increased renal secretion of potassium is a cause.
Addison disease is a cause.
It often occurs in acidosis
Hyperkalemia (high potassium) often occurs with acidosis. During acidosis, hydrogen is taken up in the cell; when this occurs, it is exchanged for potassium and serum potassium rises. Dietary excesses are uncommon. Addison disease is a cause of hyperkalemia because there is decreased secretion of aldosterone. Aldosterone promotes the secretion of potassium.
Which of the following is NOT an appropriate treatment for hyperkalemia? Calcium gluconate Treating the contributing cause Administering glucagon Sodium bicarbonate
Administering glucagon
Administering glucose with insulin is an appropriate treatment. Glucagon is used in beta-blocker overdose or in hypoglycemia. Calcium gluconate and bicarbonate and treating the contributing cause are all appropriate.
Which of the following is a TRUE statement regarding hypocalcemia?
It occurs with serum concentration below 8.5 mg/dl.
It occurs with increases of vitamin D.
It occurs with increases in parathyroid hormone.
Metabolic acidosis is a known cause.
It occurs with serum concentration below 8.5 mg/dl.
When the serum concentration falls below 8.5 mg/dl, there is a deficiency of calcium. It occurs with vitamin D and parathyroid hormone deficiency. Metabolic and respiratory alkalosis are causes of the symptoms.
