Question 1

Decreased neuromuscular excitability can be seen in which two electrolyte disorders?

Accepted Answer

Hypercalcemia and hypermagnesemia both can lead to decreased neuromuscular excitability. High levels of calcium and magnesium ions in the extracellular fluid can inhibit the release of acetylcholine from nerve endings and impair the depolarization of muscle fibers, leading to muscle weakness and decreased reflexes.

Question 2

Hypermagnesemia and hypercalcemia both cause excessive neuromuscular excitability.

Accepted Answer

Hypermagnesemia causes neuromuscular depression, while hypercalcemia can, in some cases, cause muscle weakness but more commonly leads to decreased neuromuscular excitability due to increased calcium binding to sodium channels.

Question 3

Administration of 5% dextrose in water (D₅W) is an effective way to manage saline deficit.

Accepted Answer

Administration of 5% dextrose in water is not an effective way to manage saline deficit as it does not contain sufficient electrolytes to replace lost fluids and salts. Saline solutions such as 0.9% sodium chloride are usually used to manage saline deficit.

Question 4

Filtration and diffusion are passive mechanisms of capillary transport.

Accepted Answer

Filtration and diffusion are both passive mechanisms of capillary transport, meaning they do not require energy input. Filtration involves the movement of fluid and solutes from an area of high pressure to an area of low pressure, while diffusion involves the movement of solutes from an area of high concentration to an area of low concentration.

Question 5

One liter of fluid weighs about one pound.

Accepted Answer

One liter of fluid weighs approximately 2.2 pounds, so it is false that one liter of fluid weighs about one pound.

Question 6

Which of the following statements best describes the pathophysiologic process of hypernatremia?

Accepted Answer

Hypernatremia is defined as a serum sodium level above 145 mEq/L. It occurs when there is excess extracellular fluid tonicity or relative water deficit. Increased extracellular osmolality leads to water moving out of the cells causing them to shrink or shrivel. This can cause neurological symptoms such as confusion, seizures, and coma.

Question 7

If an individual with normal fluid balance is given 2 L of normal saline, how will this fluid distribute in the body (assuming no excretion)?

Accepted Answer

Normal saline is a hypertonic solution that contains a high concentration of sodium and chloride ions, making it primarily an extracellular fluid. Therefore, if an individual with normal fluid balance is given 2 L of normal saline, the fluid will distribute mainly in the extracellular fluid compartment.

Question 8

Patients with water deficit have an elevated serum osmolality.

Accepted Answer

In patients with water deficit, there is an increase in the concentration of solutes in the blood, which leads to an elevated serum osmolality.

Question 9

Hypernatremia causes cells to accumulate sodium and water so that they swell.

Accepted Answer

Hypernatremia causes cells to lose water and shrink due to the high concentration of sodium outside the cells, leading to water moving out of the cells to balance the concentration.

Question 10

Abnormalities in intracellular regulation of enzyme activity and cellular production of ATP are associated with

Accepted Answer

Hypophosphatemia can cause abnormalities in intracellular regulation of enzyme activity and cellular production of ATP, leading to fatigue and muscle weakness.

Question 11

Which of the following serum electrolyte values is abnormal?

Accepted Answer

The normal range for serum calcium is 8.5-10.5 mg/dL, so a value of 10.0 mEq/L is outside of the normal range. The values for magnesium, potassium, and phosphate are all within normal limits.

Question 12

An increase in the resting membrane potential (hyperpolarized) is associated with

Accepted Answer

Hypokalemia increases the resting membrane potential.Hyperkalemia results in hypopolarization.Hypocalcemia and hypercalcemia do not affect the resting membrane potential.

Question 13

The primary force promoting fluid movement from the capillary to the interstitium is capillary oncotic pressure.

Accepted Answer

The primary force promoting fluid movement from the capillary to the interstitium is capillary hydrostatic pressure, not oncotic pressure. Capillary oncotic pressure actually helps to prevent fluid from leaving the capillary by exerting a pulling force on water molecules, which balances out the pushing force of capillary hydrostatic pressure.

Question 14

Patients with pure saline deficit have normal serum sodium concentrations.

Accepted Answer

Pure saline deficit refers to a loss of isotonic fluid (containing normal salt concentration) from the body. This would lead to a decrease in total body volume, but not necessarily a change in serum sodium concentration. Therefore, patients with pure saline deficit can have normal serum sodium concentrations.

Question 15

Which of the following is likely to lead to hyponatremia?

Accepted Answer

Frequent nasogastric tube irrigation with water can dilute the sodium levels in the body, leading to hyponatremia. Insufficient ADH secretion can lead to hypernatremia, excess aldosterone secretion can lead to hypernatremia, and administration of intravenous normal saline can increase sodium levels or maintain them, but not lead to hyponatremia.

Question 16

Orthostatic hypotension is a manifestation of saline deficit.

Accepted Answer

Orthostatic hypotension is a condition where there is a drop in blood pressure when standing up from a sitting or lying position. One of the common causes of orthostatic hypotension is a deficit in saline or fluids in the body. When there is not enough fluid volume, the blood pressure drops when standing, leading to symptoms such as dizziness, lightheadedness, and fainting. Therefore, orthostatic hypotension is a manifestation of saline deficit.

Question 17

The most appropriate therapy for an individual with hypernatremia is

Accepted Answer

The most appropriate therapy for hypernatremia is hypotonic fluids, such as 0.45% saline or D5W, to dilute the excess sodium and lower serum sodium levels. Volume expansion with normal saline or administration of colloids may further increase sodium levels, while diuretics may worsen dehydration and exacerbate hypernatremia.

Question 18

The best indicator of extracellular (saline) volume status would be

Accepted Answer

Weight change is the best indicator of extracellular volume status because it directly reflects changes in body fluid volume, including saline (extracellular) volume.

Question 19

Osmoreceptors located in the hypothalamus control the release of

Accepted Answer

Osmoreceptors in the hypothalamus detect changes in the concentration of solutes in the blood and signal for the release of vasopressin (ADH) from the posterior pituitary gland. This hormone regulates water balance in the body by causing the kidneys to reabsorb more water, reducing urine output, and increasing blood volume and blood pressure. The other hormones listed (angiotensin, atrial natriuretic peptide, and aldosterone) play roles in regulating blood volume and electrolyte balance, but they are not directly controlled by osmoreceptors in the hypothalamus.

Question 20

Two thirds of body fluids are within the intracellular fluid compartments.

Accepted Answer

Two thirds of body fluids are indeed within the intracellular fluid compartments, while the remaining one third is in extracellular fluid compartments such as interstitial fluid, plasma, and transcellular fluid.

Quiz 24: Fluid and Electrolyte Homeostasis and Imbalances

Decreased neuromuscular excitability can be seen in which two electrolyte disorders?

Hypermagnesemia and hypercalcemia both cause excessive neuromuscular excitability.

Administration of 5% dextrose in water (D₅W) is an effective way to manage saline deficit.

Filtration and diffusion are passive mechanisms of capillary transport.

One liter of fluid weighs about one pound.

Which of the following statements best describes the pathophysiologic process of hypernatremia?

If an individual with normal fluid balance is given 2 L of normal saline, how will this fluid distribute in the body (assuming no excretion) ?

Patients with water deficit have an elevated serum osmolality.

Hypernatremia causes cells to accumulate sodium and water so that they swell.

Abnormalities in intracellular regulation of enzyme activity and cellular production of ATP are associated with

Which of the following serum electrolyte values is abnormal?

An increase in the resting membrane potential (hyperpolarized) is associated with

The primary force promoting fluid movement from the capillary to the interstitium is capillary oncotic pressure.

Patients with pure saline deficit have normal serum sodium concentrations.

Which of the following is likely to lead to hyponatremia?

Orthostatic hypotension is a manifestation of saline deficit.

The most appropriate therapy for an individual with hypernatremia is

The best indicator of extracellular (saline) volume status would be

Osmoreceptors located in the hypothalamus control the release of

Two thirds of body fluids are within the intracellular fluid compartments.

Quiz 24: Fluid and Electrolyte Homeostasis and Imbalances

Decreased neuromuscular excitability can be seen in which two electrolyte disorders?

Hypermagnesemia and hypercalcemia both cause excessive neuromuscular excitability.

Administration of 5% dextrose in water (D5W) is an effective way to manage saline deficit.

Filtration and diffusion are passive mechanisms of capillary transport.

One liter of fluid weighs about one pound.

Which of the following statements best describes the pathophysiologic process of hypernatremia?

If an individual with normal fluid balance is given 2 L of normal saline, how will this fluid distribute in the body (assuming no excretion) ?

Patients with water deficit have an elevated serum osmolality.

Hypernatremia causes cells to accumulate sodium and water so that they swell.

Abnormalities in intracellular regulation of enzyme activity and cellular production of ATP are associated with

Which of the following serum electrolyte values is abnormal?

An increase in the resting membrane potential (hyperpolarized) is associated with

The primary force promoting fluid movement from the capillary to the interstitium is capillary oncotic pressure.

Patients with pure saline deficit have normal serum sodium concentrations.

Which of the following is likely to lead to hyponatremia?

Orthostatic hypotension is a manifestation of saline deficit.

The most appropriate therapy for an individual with hypernatremia is

The best indicator of extracellular (saline) volume status would be

Osmoreceptors located in the hypothalamus control the release of

Two thirds of body fluids are within the intracellular fluid compartments.

Administration of 5% dextrose in water (D₅W) is an effective way to manage saline deficit.