Deck 27: Water, Electrolyte, and Acid-Base Balance

Question 1

Which of the following individuals would have the largest percentage of their body weight 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 1

A

Question 2

The predominant extracellular cation is ________.

A) bicarbonate
B) Na⁺
C) Cl⁻
D) K⁺
E) H⁺

Answer 2

B

Question 3

The predominant extracellular anion is ________.

A) protein
B) phosphate
C) bicarbonate
D) Cl⁻
E) Na⁺

Answer 3

D

Question 4

As the rate of sweat production increases, the amount of Na⁺ lost in the urine ________.

A) increases
B) decreases
C) remains the same

Question 5

When aldosterone is absent, Na⁺ reabsorption in the nephron is ________.

A) greatly increased
B) greatly decreased
C) unchanged

Question 6

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

A) protein
B) bicarbonate
C) Cl⁻
D) water volume
E) H⁺

Question 7

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 8

The major route of excretion for Na⁺ (under normal conditions) is the ________.

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

Question 9

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 10

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 11

Extracellular fluid has a ________.

A) higher protein content than intracellular fluid
B) higher K⁺ content than intracellular fluid
C) higher Na⁺ content than intracellular fluid
D) higher Mg²⁺ content than intracellular fluid
E) higher number of large organic molecules than intracellular fluid

Question 12

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 13

Renin is released by the ________.

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

Question 14

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

A) Plasma
B) Interstitial
C) Intracellular
D) Extracellular
E) Cytoplasm

Question 15

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

A) Na⁺
B) K⁺
C) Cl⁻
D) phosphate
E) H⁺

Question 16

The predominant intracellular cation is ________.

A) K⁺
B) Na⁺
C) Ca²⁺
D) Mg²⁺
E) Cl⁻

Question 17

Serum electrolyte concentrations are most often expressed as ________.

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

Question 18

The distribution of Na⁺ and K⁺ between intracellular and extracellular compartments is ________.

A) K⁺ mainly intracellular; Na⁺ mainly in extracellular
B) Na⁺ mainly intracellular; K⁺ 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 the choices are correct.

Question 19

Where is the highest concentration of bicarbonate ion found?

A) Plasma
B) Intracellular fluid
C) Interstitial fluid
D) Lymph

Question 20

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

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

Question 21

Oversecretion of aldosterone causes ________.

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

Question 22

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 23

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 the kidneys' afferent arterioles
E) blood pressure in the ventricles of the heart.

Question 24

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 25

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 26

Which 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 Na⁺ concentration inside the cell

Question 27

Which of the following statements concerning K⁺ is false?

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

Question 28

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 29

A decrease in plasma osmolality would increase ________.

A) ADH production
B) plasma Na⁺ levels
C) renin production
D) urine production
E) thirst

Question 30

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

Question 31

Decreased extracellular K⁺ levels cause

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

Question 32

Which of the following events occurs last?

A) Release of renin by the kidney
B) Release of aldosterone by the adrenal cortex
C) Sodium ion reabsorption by the kidney tubules
D) Angiotensinogen → angiotensin I
E) Angiotensin I → angiotensin II

Question 33

Which of the following would be expected to cause hyponatremia?

A) High intake of Na⁺
B) Increased aldosterone production
C) Increased urine output
D) Decreased aldosterone production
E) Decreased ADH production

Question 34

Potassium levels in the body are regulated by ________.

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

Question 35

The primary regulator of plasma Na⁺ concentration is ________.

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

Question 36

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 37

Atrial natriuretic hormone increases ________.

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

Question 38

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 39

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 40

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 41

Aldosterone secretion may be stimulated by ________.

A) ADH
B) elevated K⁺ levels
C) excess water intake
D) elevated Na⁺ levels
E) low K⁺ levels

Question 42

Parathyroid hormone affects 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 43

Hyperkalemia is defined as

A) excess excitability of kalems.
B) reduction of plasma Ca²⁺ level.
C) increase in plasma K⁺ level.
D) increase in plasma Na⁺ level.
E) decrease in plasma K⁺ level.

Question 44

Calcitonin

A) promotes the absorption of Ca²⁺ from the gastrointestinal tract.
B) promotes osteoclast activity in the bones.
C) reduces Ca²⁺ excretion by the kidneys.
D) reduces extracellular Ca²⁺ ion levels.
E) increases blood Ca²⁺ levels.

Question 45

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 46

In hypocalcemia,

A) depolarization is prevented.
B) PTH production is reduced.
C) blood Ca²⁺ levels are increased.
D) neuromuscular excitability increases.
E) neuromuscular excitability decreases.

Question 47

Increased osmolality of the extracellular fluid

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

Question 48

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 Na²⁺ retention.
B) increased plasma volume.
C) decreased plasma Ca²⁺.
D) delayed healing.
E) increased plasma Ca²⁺.

Question 49

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 50

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

A) K⁺
B) Ca²⁺
C) calcitonin
D) phosphate
E) Na⁺

Question 51

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 the choices are correct.

Question 52

What is the main role of Mg²⁺ in the body?

A) Muscle contraction
B) Nerve impulse
C) Blood clotting
D) Cofactors for intracellular enzymes

Question 53

Adequate Ca²⁺ absorption from the GI tract depends on

A) serum K⁺ levels.
B) serum calcitonin levels.
C) adequate amounts of vitamin D.
D) the osmolality of the extracellular fluid.
E) adequate amounts of vitamin C.

Question 54

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 55

Most of the Ca²⁺ in the body is in the ________.

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

Question 56

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 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

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 59

Oversecretion of aldosterone causes

A) decreased secretion of Ca²⁺ by the kidney.
B) increased secretion of K⁺ by the kidney.
C) decreased reabsorption of Na⁺ by the kidney.
D) increased reabsorption of phosphate ions by the kidney.
E) decreased secretion of K⁺ by the kidney.

Question 60

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 K⁺ in the urine.
D) increased rate of Ca²⁺ excretion by the kidneys.
E) decreased levels of blood Ca²⁺.

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

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 63

Which of the following substances releases H⁺ into a solution?

A) Acids
B) Bases
C) Salts
D) Glucose
E) Water

Question 64

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 65

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 66

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 67

If the H⁺ concentration in the blood increases, bicarbonate ions act as buffers by

A) removing excess H⁺ from the plasma.
B) releasing H⁺ into the plasma.
C) dissociating into H+ and CO₃⁻.
D) combining with Cl⁻.
E) combining with hemoglobin.

Question 68

Body fluid pH will rise dramatically when

A) Na⁺ is excreted by the kidney.
B) large amounts of bicarbonate are ingested.
C) carbonic acid is formed.
D) the respiratory rate decreases.
E) CO₂ levels increase.

Question 69

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 70

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.

Question 71

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

A) Ammonia
B) Bicarbonate ions
C) Phosphate ions
D) All of the choices are correct.

Question 72

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 73

An increase in blood CO₂ levels is followed by a/an ________ in H⁺ ions and a/an ________ in blood pH.

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

Question 74

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 75

Angiotensin II increases blood volume by stimulating

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

Question 76

As a result of hyperventilation,

A) the body pH decreases.
B) the plasma P_CO2 level decreases.
C) the kidney will increase the rate of H⁺ excretion.
D) more bicarbonate ions are added to the plasma.
E) the plasma P_CO2 level increases.

Question 77

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 78

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

A) Acidosis
B) pH increases
C) H⁺ concentration increases
D) Carbonic acid levels increase
E) pH decreases

Question 79

Wilma'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 80

pH

A) increases with acidity.
B) is measured on a scale of 0 to 10.
C) is a measure of the H⁺ concentration.
D) reflects Na⁺ content of body fluids.
E) is not related to amounts of CO₂ in the body.