Deck 14: Fluid and Acid-Base Balance

Question 1

The barrier between the plasma and interstitial fluid

A) is the blood vessel walls.
B) is the plasma membrane.
C) transports materials between these two fluid compartments by both passive and active means.
D) two of these answers.
E) all of these answers.

Answer 1

is the blood vessel walls.

Question 2

Extracellular fluid

A) includes plasma.
B) includes interstitial fluid.
C) constitutes a smaller percentage of total body water than does intracellular fluid.
D) includes both plasma and interstitial fluid.
E) all of these answers.

Answer 2

all of these answers.

Question 3

Which factor is controlled by vasopressin?

A) ECF volume
B) ECF osmolarity
C) maintenance of free water balance
D) both (a) and (b)
E) both (b) and (c)

Answer 3

both (b) and (c)

Question 4

Interstitial fluid

A) is the largest component of the extracellular fluid.
B) is the true internal environment of the body.
C) represents a larger percentage of total body weight than does intracellular fluid.
D) both (a) and (b)
E) all of these answers.

Question 5

The primary reason that extracellular fluid volume must be closely regulated is

A) to prevent changes in ICF osmolarity.
B) to maintain adequate urine formation.
C) to maintain proper blood pressure.
D) to prevent cells from swelling or shrinking.
E) to allow changes in ICF volume.

Question 6

Which of the following does not occur during water deficit?

A) ECF volume increases
B) increase release of vasopressin
C) decreased urine output
D) increased thirst
E) all of the above occur

Question 7

The component that constitutes the largest percentage of body weight is

A) protein.
B) H₂O.
C) Na⁺.
D) carbohydrate.
E) phospholipid.

Question 8

Why would eating a very salty snack make you thirsty?

A) it would cause decreased ECF volume.
B) it would decrease the osmolarity of the ECF.
C) it would inhibit the hypothalamic osmoreceptors.
D) it would stimulate the hypothalamic osmoreceptors.
E) it would immediately cause more urine output.

Question 9

A ____ exists when total body input of a particular substance exceed its total body output.

A) positive balance.
B) negative balance.
C) stable balance.
D) state of equilibrium.
E) steady state.

Question 10

When water is lost from the ECF but electrolytes are retained

A) both ECF and ICF become more dilute.
B) cells will lose water
C) the osmolarity of the ECF drops.
D) there is an increase in the volume of the ICF
E) water levels remain unchanged

Question 11

The major source of controlled water loss from the body is

A) feces.
B) respiratory loss.
C) skin loss.
D) sweat.
E) urine.

Question 12

The primary anion in the extracellular fluid is

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

Question 13

When large amounts of pure water are consumed

A) the volume of the ICF will decrease.
B) the volume of the ECF will decrease.
C) the ECF becomes hypertonic to the ICF.
D) osmolarities of the ICF and ECF will drop.
E) vasopressin will be released

Question 14

The tissue in the body containing the lowest percentage of water is the

A) skin.
B) skeleton.
C) muscle.
D) internal organs.
E) adipose (fat).

Question 15

The ICF contains about ____ of the total water of the body.

A) 1/10
B) 1/4
C) 1/2
D) 2/3
E) 5/6

Question 16

The ion in greatest concentration within the cytoplasm is

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

Question 17

Variation in percent body water among individuals is primarily due to differences in

A) amount of adipose tissue.
B) total muscle mass.
C) vasopressin secretion.
D) drinking habits.
E) glomerular filtration rate.

Question 18

The primary ECF cation is ____, and the primary ICF cation is ____.

A) K⁺, Na⁺
B) K⁺, Ca²⁺
C) Ca²⁺, Na⁺
D) Na⁺, K⁺
E) Na⁺, Ca²⁺

Question 19

Which of the following are compensatory measures for a fall in arterial blood pressure?

A) increased cardiac output and increased total peripheral resistance as a result of the baroreceptor reflex.
B) a shift of fluid out of the interstitial compartment into the vasculature.
C) a reduction in the urinary excretion of salt and accompanying fluid.
D) both (a) and (b) above.
E) all of these answers.

Question 20

Extracellular fluid

A) constitutes a greater percentage of total body water than does intracellular fluid.
B) osmolarity must be regulated to prevent an acid-base imbalance because the hydrogen ions might become too concentrated or too dilute in the body fluids.
C) volume must be regulated to prevent the cells from swelling or shrinking.
D) is composed of interstitial and intracellular fluids
E) none of the above

Question 21

If an individual is overhydrated,

A) H₂O will move by osmosis into the cells.
B) both the ECF and ICF compartments will be hypotonic after the fluid shift has occurred.
C) symptoms might include confusion, headache, lethargy, weakness, and edema.
D) two of these answers.
E) all of these answers.

Question 22

All of the following will occur during water intoxication except

A) ICF hypotonicity.
B) ECF hypotonicity circulatory.
C) excess free water retention.
D) water movement from ICF to ECF.
E) overhydration.

Question 23

If the ECF's osmolarity increases

A) water will shift from the ICF into the ECF.
B) water will not shift between the ECF and the ICF.
C) water will move from the ECF into the ICF.
D) vasopressin secretion will decrease.
E) potassium and sodium will compensate.

Question 24

Which of the following is not a potential cause of hypertonicity in the body?

A) water deprivation.
B) heavy sweating.
C) excess vasopressin secretion.
D) diabetes insipidus.
E) severe diarrhea.

Question 25

When there is excess Na⁺ in the body,

A) the plasma volume is expanded, and arterial blood pressure is increased.
B) as a compensatory measure, the GFR is increased.
C) as a compensatory measure, urine output decreases
D) both (a) and (b) above.
E) all of these answers.

Question 26

Which of the following statements concerning hypotonicity is correct?

A) during hypotonicity, water enters the cells by osmosis.
B) the only cause of hypotonicity is drinking excess fluid.
C) hypotonicity is a major consequence of diabetes mellitus, which is a deficiency of vasopressin.
D) hypotonicity is usually associated with a negative water balance.
E) common symptoms of hypotonicity include dry skin and sunken eyeballs.

Question 27

The vast majority of the extracellular fluid's osmotic activity is contributed by

A) plasma proteins.
B) Na⁺ and its attendant anions.
C) K⁺ and its attendant anions.
D) Ca²⁺ and its attendant anions.
E) red blood cells.

Question 28

When isotonic fluid is added to the ECF, fluid will

A) shift from the ICF into the ECF.
B) not shift between the ECF and ICF.
C) shift from the ECF into the ICF.
D) none of these answers.

Question 29

The importance of regulating ECF osmolarity is

A) to help maintain blood pressure.
B) to prevent the urine from becoming too concentrated.
C) to prevent fluid shifts between the cells and the extracellular fluid, which could produce profound symptoms as the cells swell or shrink.
D) to prevent spontaneous depolarization of nerve and muscle cell membranes because of shifts in Na⁺ balance.
E) to prevent an acid-base imbalance if the hydrogen ions were to become too concentrated or too dilute in the body fluids.

Question 30

The baroreceptor reflexes affect sodium balance by

A) causing release of renin.
B) causing the release of vasopressin.
C) lowering GFR through vasoconstriction of afferent arterioles.
D) lowering GFR through vasodilation of afferent arterioles.
E) none of these answers.

Question 31

Salt balance in humans

A) depends primarily upon control of Na⁺ intake through salt hunger.
B) depends primarily upon control of Na⁺ output by the kidneys.
C) is poorly regulated.
D) depends upon Na⁺ secretion by the kidneys.
E) is not affected by aldosterone secretion.

Question 32

Diabetes insipidus

A) is due to excess vasopressin secretion.
B) results in decreased urine production
C) gives rise to hypertonicity of the ECF
D) is caused by changes in insulin levels
E) results in water moving into cells by osmosis

Question 33

Sodium is directly or indirectly controlled through all these mechanisms except

A) the baroreceptor reflexes.
B) the renin-angiotensin mechanism.
C) aldosterone activity.
D) changes in kidney function
E) sweat production

Question 34

Hypothalamic osmoreceptors are nearest to

A) angiotensin-secreting cells.
B) carotid baroreceptors.
C) the adrenal cortex.
D) the adrenal medulla.
E) vasopressin-secreting cells.

Question 35

If an individual becomes dehydrated

A) increased facultative reabsorption of water occurs.
B) urinary output increases.
C) vasopressin secretion is decreased.
D) the ECF osmolarity becomes hypotonic.
E) all of these answers.

Question 36

A drop in arterial blood pressure would trigger

A) decreased GFR.
B) release of aldosterone.
C) increased sodium reabsorption.
D) decreased chloride excretion.
E) all of these answers.

Question 37

Which is a source of water input?

A) fluid intake
B) ingested food
C) chemical reactions within the cells that convert food and O₂ into energy
D) both (a) and (b) above.
E) all of these answers.

Question 38

The main control for salt balance is

A) control of salt intake.
B) control of salt output in the sweat.
C) control of salt output in the feces.
D) control of salt output in the urine.
E) regulation through salt hunger.

Question 39

Osmotic activity across the

A) capillary wall is not due to the unequal distribution of plasma proteins in the plasma and interstitial fluid.
B) cellular plasma membranes is not related to any differences in ionic concentration between the ECF and ICF.
C) cellular plasma membranes is not related to differences in protein composition between the ECF and ICF.
D) both (a) and (b) above.
E) both (a) and (c) above.

Question 40

The amount of Na⁺ excreted in the urine equals the amount of Na⁺ ____ minus the amount of Na⁺ ____.

A) filtered, reabsorbed
B) ingested, filtered
C) ingested, metabolically consumed
D) ingested, placed in storage
E) secreted, reabsorbed

Question 41

Normal blood pH

A) is slightly basic.
B) is slightly alkaline.
C) falls between 7.35 and 7.45.
D) varies greatly.
E) both (a) and (c) above.

Question 42

pH is

A) equal to log 1/[H⁺].
B) is a measure osmolarity of a solution
C) high when acidosis is present.
D) always below 7.0
E) none of the above

Question 43

Vasopressin

A) is released when hypothalamic osmoreceptors are activated.
B) atrial volume are activated.
C) causes increased systemic vasoconstriction.
D) both (a) and (b) above.
E) all of these answers.

Question 44

Solution A has a pH of 3, solution B has a pH of 6. Which statement is true?

A) Both solutions are considered acids
B) Solution A is an acid, solution B is a base
C) Solution A is half as strong an acid as solution B
D) Solution A is twice as strong an acid as solution B
E) none of the above

Question 45

Chemical buffer systems

A) can act within a fraction of a second to buffer changes in [H⁺].
B) are the only mechanism available for regulating changes in [H⁺] within the body.
C) actually eliminate acid from the body.
D) both (a) and (c) above.
E) all of these answers.

Question 46

Select the primary buffer system in the ECF.

A) bicarbonate/carbonic acid.
B) chloride/hydrochloric acid.
C) hemoglobin.
D) phosphate.
E) protein.

Question 47

The primary buffer in the ICF is

A) hemoglobin.
B) phosphate buffer system.
C) H₂CO₃: HCO₃^- buffer system.
D) proteins.
E) respiratory regulation.

Question 48

What is the primary regulatory mechanism to maintain water balance in the body?

A) control of intake through thirst.
B) control of sweating
C) control of output through regulation of urine production by the kidney
D) oral metering
E) control of insensible water loss

Question 49

Normal body fluids are:

A) slightly acidic
B) slightly basic
C) neutral
D) mildly acidic
E) mildly basic

Question 50

H₂ generated from CO₂ at the tissue level is

A) the major source of hydrogen ion in the body.
B) normally buffered in transit between the tissues and the lungs by hemoglobin.
C) responsible for the fact that the pH of the venous blood is higher than the pH of the arterial blood.
D) both (a) and (b) above.
E) all of these answers.

Question 51

Chemical buffer systems

A) respond in 1 to 3 minutes to changes in hydrogen ion concentration.
B) stimulate the respiratory center when acidosis is present.
C) promote H⁺ excretion by the kidneys when acidosis is present.
D) are the most powerful mechanism available for regulating changes in [H⁺] within the body.
E) buffers changes in acid or base levels.

Question 52

pH

A) equals the logarithm to the base 10 of the reciprocal of the hydrogen-ion concentration.
B) can be calculated if the HCO₃^- and CO₂ concentration in the body fluids is known, even if the H⁺ concentration is unknown.
C) is higher in arterial blood than venous blood.
D) both (a) and (b) above.
E) all of these answers.

Question 53

Metabolic water

A) results from cellular respiration.
B) Is roughly 15% of daily water input.
C) Its production increases during times of dehydration to compensate for water loss.
D) both (a) and (b) above.
E) both (a) and (c) above.

Question 54

When H⁺ secretion increases to compensate for acidosis, less of which of the following ions can then be secreted?

A) calcium
B) chloride
C) phosphate
D) potassium
E) sodium

Question 55

A pH of 4 is ____ times as acidic as a pH of 7.

A) 10
B) 100
C) 1,000
D) 10,000
E) 100,000

Question 56

The thirst mechanism is invoked when

A) the plasma osmolarity increases.
B) the plasma osmolarity decreases.
C) hypothalamic osmoreceptors are activated.
D) both (a) and (b) above.
E) both (a) and (c) above.

Question 57

Sensible water loss includes loss

A) during cellular metabolism.
B) from the lungs.
C) from sweat.
D) in the feces.
E) from urine

Question 58

Which of the following is normally the major source of hydrogen ions in the body?

A) phosphoric and sulfuric acids formed during the metabolism of dietary proteins.
B) lactic acid production by the muscles during exercise.
C) carbonic acid generated from metabolically produced CO₂.
D) natural acids found in foods, such as citric acid.
E) fatty acids produced during fat metabolism.

Question 59

Which chemical buffer system primary buffers against pH changes in the urine?

A) bicarbonate.
B) protein.
C) hemoglobin.
D) phosphate
E) carbon dioxide

Question 60

Which of the following is not influenced by a change in the pH of body fluids?

A) phosphate excretion.
B) enzyme activity.
C) potassium excretion.
D) protein shape and activity.
E) nerve and muscle excitability.

Question 61

To compensate for changes in ECF volume, fluid shifts occur temporarily and automatically between the plasma and intracellular fluid.

Question 62

The percentage of body water varies from person to person.

Question 63

Which of the following can cause respiratory alkalosis?

A) anxiety attack
B) COPD
C) excess fat metabolism
D) diabetes mellitus
E) elevated levels of carbon dioxide

Question 64

The H₂O content of an individual remains fairly constant, largely because the kidneys efficiently regulate H₂O balance.

Question 65

During respiratory compensation for metabolic alkalosis

A) breathing becomes shallower.
B) breathing becomes slower.
C) CO₂ levels in the body decrease.
D) both (a) and (b) above.
E) both (b) and (c) above.

Question 66

The kidney tubular cells secrete NH₃

A) when the urinary pH becomes too high.
B) when the body is in a state of alkalosis.
C) to buffer the acid phosphate excreted in the urine.
D) when there is excess NH₃ in the body fluid.
E) to enable further renal secretion of H⁺.

Question 67

The kidneys control the pH of the body fluids by adjusting:

A) hydrogen excretion
B) bicarbonate excretion
C) ammonia secretion
D) (a) and (b)
E) all of the above

Question 68

Extracellular fluid is divided into two compartments, the plasma fluid and the interstitial fluid.

Question 69

The tissue with the lowest percentage of water is the skeleton.

Question 70

Which of the following statements concerning the respiratory mechanism of pH control is correct?

A) respiratory rate and depth increase as a compensatory measure to combat metabolic acidosis.
B) the respiratory system can compensate completely for metabolic acidosis.
C) the respiratory responses to acid-base imbalances represent the first line of defense against changes in pH of the body fluids.
D) hyperventilation can cause acidosis
E) the respiratory system responds to changes in [H⁺] within 1 to 3 seconds

Question 71

Extracellular fluid volume depends primarily on the sodium load in the body.

Question 72

Water is freely permeable through all cell membranes.

Question 73

Vomiting of gastric contents

A) can lead to dehydration.
B) can cause metabolic acidosis.
C) can cause metabolic alkalosis.
D) both can lead to dehydration and cause metabolic acidosis.
E) both can lead to dehydration and cause metabolic alkalosis.

Question 74

Water is the most abundant component of the body, making up over 95% of the body weight.

Question 75

If plasma H⁺ levels rise which of the following occur at the kidney to compensate?

A) bicarbonate is secreted
B) bicarbonate is conserved
C) H⁺ are conserved
D) ammonia is reabsorbed
E) none of the above

Question 76

The main reason ECF volume must be regulated is to maintain proper cell volume.

Question 77

When the concentration of H⁺ increases above normal, for compensation the response is a(n)

A) decreased excretion of H⁺ in the urine.
B) increased concentration of H⁺ in the plasma.
C) increased reabsorption of all filtered bicarbonate ions.
D) increased secretion of aldosterone from the posterior pituitary.
E) synthesis of H⁺ by acid dissociation.

Question 78

Under conditions of severe pH changes, which system can return the pH almost exactly to normal?

A) chemical buffers
B) respiratory system
C) urinary system
D) requires the function of both (b) and (c)
E) no system can return the pH to exactly normal values

Question 79

Which of the following conditions would be a cause of metabolic acidosis?

A) severe diarrhea.
B) severe vomiting.
C) aspirin poisoning.
D) emphysema.
E) none of these answers.

Question 80

The amount of salt in sweat is the major, controlled excretion of salt.