Deck 13: Fluid and Acid Base Balance

Question 1

What happens 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.

Answer 1

D

Question 2

Which statement is correct concerning transcellular fluid?

A) It is the sum of fluid within all of the cells.
B) It consists of a number of small specialized fluid volumes, all of which are secreted by specific cells into a particular body cavity to perform a specialized function.
C) It plays a crucial role in fluid balance.
D) It includes the lymph.

Answer 2

B

Question 3

What is the primary anion of the ECF?

A) bicarbonate
B) chloride
C) sodium ion
D) potassium ion

Answer 3

B

Question 4

What is variation in percentage of body water among individuals primarily due to? __________

A) differences in amount of adipose tissue
B) differences in total muscle mass
C) differences in vasopressin secretion
D) differences in drinking habits

Question 5

What is the primary reason that extracellular fluid volume must be closely regulated?

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

Question 6

What is the primary electrolyte in the extracellular fluid?

A) calcium ion
B) chloride
C) potassium ion
D) sodium ion

Question 7

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

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

Question 8

Which ion has the greatest concentration in the cytoplasm?

A) calcium ion
B) chloride
C) phosphate
D) potassium ion

Question 9

Which tissues in the body contain the lowest percentage of water?

A) blood
B) skeleton
C) muscle
D) adipose

Question 10

The largest percentage of water is located in what "compartment?"

A) synovial fluids
B) plasma
C) interstitial fluids
D) intracellular fluids

Question 11

Which statement is NOT true concerning extracellular fluid?

A) It includes plasma.
B) It includes interstitial fluid.
C) It constitutes a greater percentage of total body water than does intracellular fluid.

Question 12

What is the barrier between the plasma and interstitial fluid?

A) the blood vessel walls
B) the plasma membrane
C) transports materials between these two fluid compartments by both passive and active means
D) the transcellular membrane

Question 13

Which of following is the transcellular fluid that serves as a shock absorber in the joints?

A) Intraocular
B) Pericardial
C) Peritoneal
D) Synovial

Question 14

Which statement is NOT true concerning interstitial fluid?

A) It is the largest component of the extracellular fluid.
B) It is the true internal environment of the body.
C) It represents a larger percentage of total body weight than does intracellular fluid.

Question 15

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.

Question 16

What happens when water is lost from the ECF but electrolytes are retained?

A) Both ECF and ICF become more dilute.
B) Osmosis moves water from the ICF to the ECF.
C) The osmolarity of the ECF drops.
D) There is an increase in the volume of the ICF.

Question 17

Which constitutes the largest percentage of body weight?

A) protein
B) H2O
C) Na+
D) carbohydrate

Question 18

What exists when total body input of a particular substance equals its total body output?

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

Question 19

The ICF contains about how much of the total water of the body?

A) 1/10
B) ¼
C) ½
D) 2/3

Question 20

What is the major source of water loss from the body?

A) insensible respiratory loss
B) insensible skin loss
C) sweat
D) urine

Question 21

What will happen 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.

Question 22

Which statement is NOT true concerning diabetes insipidus?

A) It is due to excess vasopressin secretion.
B) It is due to vasopressin deficiency.
C) It gives rise to hypertonicity of the ECF.

Question 23

Which statement is not true if an individual is overhydrated?

A) H2O will move by osmosis into the cells.
B) Both the ECF and ICF compartments will be hypertonic after the fluid shift has occurred.
C) Symptoms might include confusion, headache, lethargy, weakness, and edema.

Question 24

What is NOT a potential cause of hypertonicity in the body?

A) water deprivation
B) heavy sweating
C) excess vasopressin secretion
D) diabetes insipidus

Question 25

Which statement 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.

Question 26

What is the main control for salt balance?

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

Question 27

Which one of the following will NOT occur during water intoxication?

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

Question 28

What would be triggered by a drop in arterial blood pressure?

A) decreased GFR
B) release of aldosterone
C) increased sodium reabsorption
D) decreased chloride excretion

Question 29

Which mechanism does NOT directly or indirectly control sodium?

A) the baroreceptor reflexes
B) the renin-angiotensin mechanism
C) aldosterone activity
D) altering gastrointestinal absorption

Question 30

Which statement is correct for salt balance in humans?

A) It depends primarily upon control of Na+ intake through salt hunger.
B) It depends primarily upon control of Na+ output by the kidneys.
C) It is poorly regulated.
D) It depends upon Na+ secretion by the kidneys.

Question 31

What happens 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.

Question 32

Which statement concerning hypotonicity of the body fluids is INCORRECT?

A) Hypotonicity can occur as a result of diabetes insipidus.
B) Hypotonicity occurs when excess free H2O is present.
C) Drowsiness, headache, confusion, lethargy, weakness, and edema are symptoms associated with hypotonicity.
D) cells become swollen.

Question 33

How do the baroreceptor reflexes affect sodium balance?

A) by causing release of renin
B) by causing the release of vasopressin
C) by lowering GFR through vasoconstriction of afferent arterioles
D) by lowering GFR through vasodilation of afferent arterioles

Question 34

When the ECF becomes hypertonic,water __________

A) Water movement is unaffected.
B) Water moves into the cells by active transport.
C) Water moves into the cells by osmosis.
D) Water moves out of the cells by osmosis.

Question 35

What is the amount of Na⁺ filtered equal to?

A) CMO ?6? GRF
B) plasma concentration ?6? CMO
C) plasma concentration ?6? GRF
D) urine output ?6? CMO

Question 36

What contributes the vast majority of the extracellular fluid's osmotic activity?

A) plasma proteins
B) Na+ and its attendant anions
C) K+ and its attendant anions
D) Ca2+ and its attendant anions

Question 37

What is the most important factor in the long-term regulation of ECF volume?

A) maintenance of salt balance
B) maintenance of water balance
C) the baroreceptor reflex
D) fluid shifts between the interstitial fluid and plasma

Question 38

What is the importance of regulating ECF osmolarity?

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

Question 39

Which of the following is not true about the 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 vasculature into the interstitial compartment
C) a reduction in the urinary excretion of salt and accompanying fluid

Question 40

What will happen when isotonic fluid is added to the ECF?

A) Fluid will shift from the ICF into the ECF
B) Fluid will not shift between the ECF and ICF
C) Fluid will shift from the ECF into the ICF
D) Fluid will move the solutes out from ICF

Question 41

Which of the following is NOT a source of water input?

A) fluid intake
B) ingested food
C) osmotic diuresis

Question 42

Which statement about acids is INCORRECT ?

A) Carbohydrates are acidic.
B) HCl is one example.
C) They can be strong or weak.
D) They dissociate to produce anions.

Question 43

What does NOT happen 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, aldosterone secretion is increased to increase the amount of Na+ reabsorbed.

Question 44

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

Question 45

Insensible water loss includes loss ___________

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

Question 46

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

Question 47

What is the pH of a solution with a H⁺ concentration of 0.0000567?

A) between 4 and 5
B) between 5 and 6
C) between 6 and 7
D) between 7 and 8

Question 48

Given the following information,what is the pH?
Ratio of [HCO₃]/[CO₂] = 20/0.5
PK = 6.1
Log of 10 = 1.0
Log of 20 = 1.3
Log of 40 = 1.6

A) pH = 7.0
B) pH = 7.4
C) = 7.7
D) It is impossible to determine the pH with the information provided.

Question 49

An increased secretion of H ions in the kidney has the greatest direct effect on the tubular secretion of which type of ions?

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

Question 50

Which statement concerning acids is INCORRECT?

A) Acids can dissociate in solution to yield free hydrogen ions and anions.
B) All substances that contain hydrogen are considered to be acids.
C) A strong acid has a greater tendency to dissociate than does a weak acid.
D) The extent of dissociation for a given acid is a constant, K.

Question 51

Which acid would be considered a strong acid?

A) one with a dissociation constant (K) = 0.05
B) one with a dissociation constant (K) = 0.10
C) one with a dissociation constant (K) = 0.47
D) one with a dissociation constant (K) = 0.99

Question 52

Which statement isNOT true for metabolic water?

A) It results from cellular respiration.
B) It is roughly 15% of daily water input.
C) Its production increases during times of dehydration to compensate for water loss.

Question 53

Which statement is NOT true for vasopressin?

A) It is released when hypothalamic osmoreceptors are activated.
B) atrial volume are activated.
C) It causes increased systemic vasoconstriction.

Question 54

Which symptom(s)is/are associated with acidosis?

A) extreme nervousness
B) disorientation and coma
C) "pins and needles" sensations
D) muscle twitches and muscle spasms

Question 55

Hypothalamic osmoreceptors are nearest to which of the following?

A) angiotensin-secreting cells
B) carotid baroreceptors
C) the adrenal cortex
D) sopressin-secreting cells

Question 56

Which statement concerning pH is NOT true?

A) It is equal to log 1/[H+].
B) It is equal to pK + log [HCO3-]/[CO2].
C) It is high when acidosis is present.

Question 57

A pH of 4 is how many times as acidic as a pH of 7?

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

Question 58

Which statement concerning pH is NOT true?

A) It equals the logarithm to the base 10 of the reciprocal of the hydrogen-ion concentration.
B) It can be calculated if the HCO3- and CO2 concentration in the body fluids is known, even if the H+ concentration is unknown.
C) It is lower in arterial blood than venous blood.

Question 59

What 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

Question 60

When is the thirst mechanism NOT invoked?

A) when the plasma osmolarity increases
B) when the plasma osmolarity decreases
C) when hypothalamic osmoreceptors are activated

Question 61

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) to enable further renal secretion of H+.

Question 62

Which statement concerning normal blood pH is not True?

A) It is slightly basic.
B) It is slightly alkaline.
C) It falls between 7.35 and 7.45.

Question 63

Which statement is NOT true for a patient with lung congestion?

A) He would have higher levels of carbonic acid in the blood.
B) He would have a slower respiratory rate.
C) He would be making use of chemical buffers to a greater extent.

Question 64

Which statement concerning HCO₃- excretion by the kidneys is INCORRECT?

A) During HCO3- reabsorption, HCO3- in the tubular fluid is actively cotransported by K+.
B) HCO3- is not excreted at pH = 7.4.
C) Secretion of H+ is accompanied by the addition of new HCO3- to the plasma.
D) HCO3- excretion increases during alkalosis.

Question 65

What is the primary buffer system in the ECF?

A) bicarbonate/carbonic acid
B) chloride/hydrochloric acid
C) haemoglobin
D) Phosphate

Question 66

When the concentration of H⁺ increases above normal,what is the compensating response?

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

Question 67

Which statement concerning the kidneys' response to increased [H⁺] in the body fluids is INCORRECT?

A) When [H+] increases, the kidneys conserve HCO3- by reabsorbing more HCO3- and reducing its excretion in the urine.
B) When [H+] increases, the kidneys secrete more H+ to be eliminated in the urine.
C) When [H+] increases, the kidneys secrete more basic phosphate to buffer the H+ in the tubular filtrate.
D) When [H+] decreases, the kidneys excrete more HCO3- into the urine.

Question 68

If the tubular filtrate becomes too acidic,what is secreted by the tubular epithelial cells to buffer the secreted H⁺?

A) HCO3-
B) OH-
C) NH3
D) NH4+

Question 69

Which statement concerning chemical buffer systems is correct?

A) They can act within a fraction of a second to buffer changes in [H+].
B) They are the only mechanism available for regulating changes in [H+] within the body.
C) They actually eliminate acid from the body.
D) They actually eliminate bicarbonate from the body.

Question 70

Which symptom(s)is/are NOT associated with alkalosis?

A) disorientation and coma
B) "pins and needles" sensations.
C) muscle twitches and muscle spasms
D) extreme nervousness

Question 71

Vomiting of gastric contents ________________

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

Question 72

If the [HCO₃-]/[CO₂] is 20/2,what is the situation?

A) uncompensated respiratory acidosis
B) uncompensated respiratory alkalosis
C) uncompensated metabolic acidosis
D) uncompensated metabolic alkalosis

Question 73

What 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

Question 74

Which statement concerning the respiratory mechanism of pH control is INCORRECT?

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 second line of defence against changes in pH of the body fluids.
D) Metabolic alkalosis inhibits (depresses) respiration.

Question 75

Which statement concerning the respiratory mechanism of pH control is correct?

A) Respiratory rate and depth decrease as a compensatory measure to combat metabolic acidosis.
B) The respiratory system can compensate completely for uremic acidosis.
C) Metabolic alkalosis inhibits (depresses) the respiratory centre.
D) The respiratory responses to acid-base imbalances represent the first line of defence against changes in pH of the body fluids.

Question 76

Which condition would be a cause of metabolic acidosis?

A) severe diarrhea
B) severe vomiting
C) aspirin poisoning
D) emphysema

Question 77

H⁺ generated at the tissue level from CO₂ is buffered in transit between the tissues and the lungs primarily by what?

A) haemoglobin
B) phosphate buffer system
C) H2CO3: HCO3- buffer system
D) plasma proteins

Question 78

Which statement concerning chemical buffer systems is correct?

A) They respond in one to three minutes to changes in hydrogen ion concentration.
B) They stimulate the respiratory centre when acidosis is present.
C) They promote H+ excretion by the kidneys when acidosis is present.
D) They buffer changes in acid or base levels.

Question 79

Which statement concerning chemical buffer systems is INCORRECT?

A) A chemical buffer system consists of a pair of substances involved in a reversible reaction, one that can yield free H+ and one that can bind with free H+.
B) A chemical buffer system minimizes changes in the pH of a solution when an acid or base is added to or removed from the solution.
C) Buffers respond to pH changes in three minutes.
D) A buffer system cannot actually eliminate hydrogen ions from the body.

Question 80

Which chemical buffer system primary buffers against carbonic acid changes?

A) Bicarbonate
B) Protein
C) haemoglobin
D) Phosphate