Deck 27: Water, Electrolytes, and Acidbase Balance

Question 1

Where is the highest concentration of bicarbonate ion found?

A) plasma
B) intracellular fluid
C) interstitial fluid
D) lymph

Answer 1

C

Question 2

Which of the following individuals would have the largest percentage of their bodyweight as water?

A) a 7-month-old female
B) a lean 35-year-old male athlete
C) a chunky 52-year-old male athlete
D) a healthy 88-year-old male
E) an adult female marathon runner

Answer 2

A

Question 3

Synovial fluid is a part of which of the following fluid compartments?

A) plasma
B) interstitial
C) intracellular
D) extracellular
E) cytoplasm

Answer 3

D

Question 4

Receptors sensitive to changes in the osmolality of extracellular fluid are the

A) baroreceptors.
B) chemoreceptors.
C) osmoreceptors.
D) pressoreceptors.
E) proprioreceptors.

Question 5

Which of the following fluid compartments contains the largest volume of water?

A) plasma
B) interstitial compartment
C) intracellular compartment
D) extracellular compartment
E) lymph

Question 6

The major route of excretion for sodium ions (under normal conditions) is the

A) skin.
B) kidney.
C) GI tract.
D) adrenal cortex.
E) sweat.

Question 7

One difference between the plasma and interstitial fluid is that the plasma has significantly more _____ than interstitial fluid.

A) protein
B) bicarbonate
C) chloride
D) water volume
E) hydrogen ions

Question 8

Which of the following fluid compartments contains the smallest volume of water?

A) plasma
B) interstitial compartment
C) intracellular compartment
D) extracellular compartment
E) cytoplasm

Question 9

Serum electrolyte concentrations are most often expressed as

A) mg %.
B) mmHg.
C) mg/dl.
D) mEq/L.
E) None of these choices is correct.

Question 10

The cation that plays a major role in determining the osmotic pressure of the plasma is

A) sodium.
B) potassium.
C) chloride.
D) phosphate.
E) hydrogen ion.

Question 11

Renin is released by the

A) lungs.
B) kidney.
C) spleen.
D) liver.
E) pancreas.

Question 12

The distribution of sodium and potassium ions between intracellular and extracellular compartments is

A) potassium mainly intracellular; sodium mainly in extracellular.
B) sodium mainly intracellular; potassium mainly in extracellular.
C) little of either intracellular but large amounts of both extracellular.
D) equal amounts of both ions, in both intracellular and extracellular fluids.
E) None of these choices is correct.

Question 13

Extracellular fluid has a

A) higher protein content than intracellular fluid.
B) higher potassium content than intracellular fluid.
C) higher sodium content than intracellular fluid.
D) higher magnesium content than intracellular fluid
E) higher number of large organic molecules than intracellular fluid.

Question 14

The predominant extracellular cation is

A) bicarbonate.
B) sodium.
C) chloride.
D) potassium.
E) hydrogen ion.

Question 15

Water moves back and forth across the plasma membrane by the process of

A) osmosis.
B) filtration.
C) facilitated diffusion.
D) active transport.
E) endocytosis.

Question 16

The predominant intracellular cation is

A) potassium.
B) sodium.
C) calcium.
D) magnesium.
E) chloride.

Question 17

The predominant extracellular anion is

A) protein.
B) phosphate.
C) bicarbonate.
D) chloride.
E) sodium.

Question 18

When aldosterone is absent, sodium reabsorption in the nephron is

A) greatly increased.
B) greatly decreased.
C) unchanged.

Question 19

As the rate of sweat production increases, the amount of sodium lost in the urine

A) increases.
B) decreases.
C) remains the same.

Question 20

Which of the following people would be most severely affected by prolonged vomiting?

A) 3-year-old male
B) 15-year-old male
C) 35-year-old male
D) 35-year-old female
E) 50-year-old male

Question 21

What characteristic of the plasma membrane is responsible for maintaining the difference between intracellular and extracellular fluid?

A) presence of channels in the membrane
B) presence of lipids in the membrane
C) being selectively permeable
D) high sodium concentration inside the cell

Question 22

Antidiuretic hormone (ADH)

A) increases plasma osmolality.
B) is secreted by the anterior pituitary.
C) increases water reabsorption in the kidneys.
D) causes the production of a large volume of urine.
E) increases urine volume.

Question 23

Which of the following events occurs last?

A) release of renin by the kidney
B) release of aldosterone by the adrenal cortex
C) sodium reabsorption by the kidney tubules
D) angiotensinogen $\rightarrow$ angiotensin I
E) angiotensin I $\rightarrow$ angiotensin II

Question 24

Which of the following is most likely to happen to a group of students who relax by drinking a pitcher of their favorite beverage?

A) an increase in urine volume
B) an increase in urine osmolality
C) an increase in ADH production
D) increased aldosterone secretion
E) a decrease in urine volume

Question 25

The stimulus for secretion of atrial natriuretic hormone is increased

A) blood osmolality.
B) aldosterone production.
C) blood pressure in atria of heart.
D) blood pressure in kidney's afferent arterioles.
E) blood pressure in the ventricles of the heart.

Question 26

Decreased extracellular potassium levels cause

A) cells to become more excitable.
B) hyperpolarization of cell membranes.
C) more action potentials to be generated.
D) increased permeability of cell membranes.
E) hypopolarization of cell membranes.

Question 27

Oversecretion of aldosterone causes

A) hyperkalemia.
B) hypercalcemia.
C) hypernatremia.
D) increased urine volume.
E) hyponatremia.

Question 28

You've been working outside in the hot sun and are dripping wet with sweat. Your fluid intake has been minimal as you have been too busy to stop and get a drink. You would expect

A) your blood osmolality to be low.
B) an increase in the production of urine.
C) aldosterone levels to decrease.
D) ADH levels to increase.
E) ADH levels to decrease.

Question 29

Increased ADH secretion could be stimulated by which of the following situations?

A) increased renal blood flow
B) increased blood osmolality
C) increased atrial natriuretic hormone production
D) increased blood pressure
E) decreased blood osmolality

Question 30

Which of the following is NOT a principle sensor for thirst regulation?

A) osmoreceptors in the hypothalamus
B) arterial baroreceptors
C) juxtaglomerular apparatus
D) mouth mucosa

Question 31

Which of the following statements concerning potassium ions is false?

A) An increase in the extracellular potassium ion concentration leads to depolarization.
B) Potassium ions are secreted into the nephron by the distal convoluted tubule.
C) When aldosterone levels are high, potassium secretion is low.
D) Aldosterone secretion is stimulated by high blood levels of potassium ions.
E) None of these choices is false.

Question 32

The primary regulator of plasma sodium concentration is

A) renin.
B) aldosterone.
C) antidiuretic hormone (ADH).
D) atrial natriuretic hormone.
E) insulin.

Question 33

A decrease in plasma osmolality would increase

A) ADH production.
B) plasma sodium levels.
C) renin production.
D) urine production.
E) thirst.

Question 34

Loss of water through diffusion and evaporation from the skin is called __________ and is important in ____________ control.

A) insensible perspiration; blood volume
B) insensible perspiration; heat loss
C) sensible perspiration; blood volume
D) sensible perspiration; temperature

Question 35

The composition of extracellular fluid has little affect on intracellular fluid amounts.

Question 36

Chloride ions

A) are cations.
B) are found only inside cells.
C) are part of the DNA molecule.
D) are regulated with Na+.
E) are not found in extracellular fluid.

Question 37

Which of the following would be expected to cause hyponatremia?

A) high intake of sodium
B) increased aldosterone production
C) increased urine output
D) decreased aldosterone production
E) decreased ADH production

Question 38

Potassium levels in the body are regulated by

A) ADH.
B) PTH.
C) calcitonin.
D) aldosterone.
E) insulin.

Question 39

Elevated blood pressure under resting conditions results in increased urinary output because

A) baroreceptors signal the hypothalamus to increase ADH secretion.
B) elevated blood pressure stimulates renin secretion.
C) the amount of angiotensin II formed is increased.
D) aldosterone levels increase.
E) baroreceptors signal the hypothalamus to decrease ADH secretion.

Question 40

Atrial natriuretic hormone increases

A) urine volume.
B) ADH secretion.
C) aldosterone secretion.
D) the reabsorption of sodium ions.
E) blood volume.

Question 41

Aldosterone secretion may be stimulated by

A) ADH.
B) elevated potassium levels.
C) excess water intake.
D) elevated sodium levels.
E) low potassium levels.

Question 42

Calcium balance is influenced by

A) ADH and parathyroid hormone levels.
B) ADH and aldosterone levels.
C) parathyroid hormone and vitamin D levels.
D) aldosterone and parathyroid hormone levels.
E) insulin and glucagon.

Question 43

What is the main role of magnesium ions in the body?

A) muscle contraction
B) nerve impulse
C) blood clotting
D) cofactors for intracellular enzymes

Question 44

Calcitonin

A) promotes the absorption of calcium from the gastrointestinal tract.
B) promotes osteoclast activity in the bones.
C) reduces calcium excretion by the kidneys.
D) reduces extracellular calcium ion levels.
E) increases blood calcium levels.

Question 45

Which of the following is correctly matched?

A) alkalosis - hypokalemia
B) cell destruction - hypokalemia
C) increased secretion of aldosterone - hyperkalemia
D) overuse of diuretics - hyperkalemia
E) acidosis - hypokalemia

Question 46

In hypocalcemia,

A) depolarization is prevented.
B) PTH production is reduced.
C) blood calcium levels are increased.
D) neuromuscular excitability increases.
E) neuromuscular excitability decreases.

Question 47

A major complication of thyroid surgery is the accidental damaging or removal of the parathyroid glands. This damage or removal of the parathyroid glands can result in

A) increased sodium retention.
B) increased plasma volume.
C) decreased plasma calcium.
D) delayed healing.
E) increased plasma calcium.

Question 48

The main regulator of serum phosphate levels is a transport process in the

A) liver.
B) kidneys.
C) pancreas.
D) small intestine.
E) large intestine.

Question 49

Increased osmolality of the ECF

A) increases thirst.
B) inhibits ADH.
C) increases renin secretion.
D) increases aldosterone secretion.
E) decreases thirst.

Question 50

The most common cause of hyperkalemia is

A) vomiting.
B) increased dietary intake.
C) increased urinary output.
D) cellular injury or death.
E) diarrhea.

Question 51

Hyperkalemia is defined as

A) excess excitability of kalems.
B) reduction of plasma calcium level.
C) increase in plasma potassium level.
D) increase in plasma sodium level.
E) decrease in plasma potassium level.

Question 52

Angiotensin II increases blood volume by stimulating

A) thirst.
B) vasodilatation.
C) water movement into the cells.
D) renal excretion of sodium.
E) ADH production.

Question 53

The sensation of thirst results from

A) an increase in the plasma volume.
B) hypertension (increased blood pressure).
C) stimulation of osmoreceptor cells in the hypothalamus.
D) a decrease in the osmolality of the extracellular fluid.
E) stimulation of baroreceptors.

Question 54

Parathyroid hormone effects the

A) bones, heart, and blood.
B) kidney, liver, and spleen.
C) intestine, kidneys, and bone.
D) liver, stomach, and small intestine.
E) stomach, pancreas, and bone.

Question 55

Stimulus for the secretion of parathyroid hormone is a decrease in serum

A) potassium levels.
B) calcium levels.
C) calcitonin levels.
D) phosphate levels.
E) sodium levels.

Question 56

An increase in parathyroid hormone levels results in

A) increased rate of bone resorption.
B) increased rate of vitamin D degradation.
C) increased concentration of potassium ions in the urine.
D) increased rate of calcium ion excretion by the kidneys.
E) decreased levels of blood calcium.

Question 57

Which of the following will the body begin to do in order to compensate for hyperkalemia?

A) vasoconstriction of blood vessels
B) increase ADH secretion
C) decrease aldosterone secretion
D) increase the release of atrial natriuretic hormone
E) increase aldosterone secretion

Question 58

Oversecretion of aldosterone causes

A) decreased secretion of calcium by the kidney.
B) increased secretion of potassium by the kidney.
C) decreased reabsorption of sodium by the kidney.
D) increased reabsorption of phosphate ions by the kidney.
E) decreased secretion of potassium by the kidney.

Question 59

Calcium's roles in the body include

A) bone health.
B) muscle contraction.
C) blood clotting.
D) action potentials in heart muscle.
E) All of these choices are correct.

Question 60

Most of the calcium in the body is in the

A) bones.
B) plasma.
C) kidneys.
D) GI tract.
E) extracellular fluid.

Question 61

Under normal conditions, most water loss from the body is through the

A) skin.
B) kidneys.
C) lungs.
D) GI tract.
E) sweat.

Question 62

As a result of hyperventilation,

A) the body pH decreases.
B) the plasma PCO₂ level decreases.
C) the kidney will increase the rate of hydrogen ion excretion.
D) more bicarbonate ions are added to the plasma.
E) the plasma PCO₂ level increases.

Question 63

Which of the following is an example of water conservation by the body?

A) diarrhea
B) perspiration
C) decreased water intake
D) decreased urine volume
E) increased urine volume

Question 64

Once alkalosis has occurred, which of the following would you expect to happen?

A) increased respiratory rate
B) a plasma pH less than 7.40
C) retention of hydrogen ions by the kidney
D) increased renal reabsorption of bicarbonate ions
E) secretion of hydrogen ions by the kidney

Question 65

An increase in blood CO₂ levels is followed by a(n) ____ in H⁺ ions and a(n) ____ in blood pH.

A) decrease, decrease
B) decrease, increase
C) increase, increase
D) increase, decrease
E) increase, no change

Question 66

Which of the following substances releases hydrogen ions into a solution?

A) acids
B) bases
C) salts
D) glucose
E) water

Question 67

Sensible perspiration

A) contains only water.
B) is water lost through simple evaporation.
C) is secreted by the sweat glands.
D) is invisible on the skin.
E) is secreted by salivary glands.

Question 68

In which of the following situations does one see large volumes of dilute urine produced?

A) ADH levels decrease
B) renin levels increase
C) aldosterone levels increase
D) parathyroid hormone levels decrease
E) ADH levels increase

Question 69

Which of the following is NOT a buffer system of the body?

A) bicarbonate buffer system
B) phosphate buffer system
C) protein buffer system
D) NaCl buffer system
E) hemoglobin buffer

Question 70

Chemicals that function to minimize changes in the pH of body fluids are called

A) buffers.
B) inhibitors.
C) accelerators.
D) activators.
E) stabilizers.

Question 71

pH

A) increases with acidity.
B) is measured on a scale of 0 to 10.
C) is a measure of the hydrogen ion concentration.
D) reflects sodium content of body fluids.
E) is not related to amounts of carbon dioxide in the body.

Question 72

A person working in the hot sun loses the greatest amount of water from the

A) lungs.
B) urine.
C) mouth.
D) skin.
E) GI tract.

Question 73

Body fluid pH will rise dramatically when

A) sodium is excreted by the kidney.
B) large amounts of bicarbonate are ingested.
C) carbonic acid is formed.
D) the respiratory rate decreases.
E) carbon dioxide levels increase.

Question 74

In renal compensation of acidosis,

A) H⁺ secretion decreases; bicarbonate excretion increases.
B) H⁺ secretion decreases; bicarbonate reabsorption increases.
C) H⁺ secretion increases; bicarbonate reabsorption increases.
D) H⁺ secretion increases; bicarbonate excretion increases.
E) H⁺ secretion decreases; bicarbonate excretion decreases.

Question 75

Mr. I.M.A. Wreck's plasma pH is 7.2. Which of the following indicates that the body is attempting to compensate and return the body pH to normal?

A) an increase in respiration rate
B) a decrease in respiration rate
C) no change in respiration rate

Question 76

If the hydrogen ion concentration in the blood increases, bicarbonate ions act as buffers by

A) removing excess hydrogen ions from the plasma.
B) releasing hydrogen ions into the plasma.
C) dissociating into H+ and CO₃^-.
D) combining with chloride ions.
E) combining with hemoglobin.

Question 77

Which of the following can play a role in buffering the pH of urine?

A) ammonia
B) bicarbonate ions
C) phosphate ions
D) ammonia and bicarbonate ions
E) ammonia, bicarbonate ions and phosphate ions

Question 78

The normal pH for blood plasma is

A) 7.00.
B) 7.25 - 7.35.
C) 7.35 - 7.45.
D) 7.45 - 7.55.
E) 6.80 - 7.20.

Question 79

Which of the following terms does not belong with the other three?

A) acidosis
B) pH increases
C) H⁺ ion concentration increases
D) carbonic acid levels increase
E) pH decreases

Question 80

Loss of a large volume of sweat will

A) decrease the hematocrit.
B) decrease ADH production.
C) increase the blood pressure.
D) increase the osmolality of body fluids.
E) decrease the osmolality of body fluids.