Deck 14: Fluid and Acidbase Balance

Question 1

Variation in percentage of body water among individuals is due primarily to which of these factors

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

Answer 1

A

Question 2

Which of these statements does NOT describe 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 and into the interstitial compartment
C)a reduction in the urinary excretion of salt and accompanying fluid
D)reabsorption of sodium by the distal tubules

Answer 2

B

Question 3

Which 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 interstitial fluid and plasma

Answer 3

A

Question 4

Which mechanism does NOT directly or indirectly control sodium

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

Question 5

Which of these elements constitutes the largest percentage of body weight

A)protein
B)H₂Oa.
C)Na+
D)carbohydrate

Question 6

The ICF contains approximately how much of the body's total water

A)1/10
B)¼
C)½
D)2/3

Question 7

What is the barrier between plasma and interstitial fluid

A)blood vessel wall
B)plasma membrane
C)pleural membrane
D)transcellular membrane

Question 8

Which statement refers to transcellular fluid

A)It is the sum of fluid within all the cells.
B)It consists of a number of small specialized fluid volumes.
C)It plays a crucial role in fluid balance.
D)It includes the lymph.

Question 9

Which of these statements does NOT refer to 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.
D)It is the fluid in between cells.

Question 10

What is the primary anion of the ECF

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

Question 11

Which of these actions would be triggered by a drop in arterial blood pressure

A)decrease of GFR
B)release of aldosterone
C)increase of sodium reabsorption
D)decrease of chloride excretion

Question 12

Which tissues in the body contain the lowest percentage of water

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

Question 13

The largest percentage of water is located in which "compartment"

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

Question 14

Which of the following 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 15

What is the primary electrolyte in the extracellular fluid

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

Question 16

Which of these conditions 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 17

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 18

Which of these statements refers to transcellular fluid

A)It is the sum of fluid within all the cells.
B)It consists of a number of small specialized fluid volumes.
C)It is important functionally and plays a crucial role in the body's fluid balance.
D)It includes the lymph fluid that returned from the interstitial fluid to the plasma.

Question 19

How do the baroreceptor reflexes affect sodium balance

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

Question 20

Which of these statements does NOT refer to 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.
D)It includes synovial fluid.

Question 21

Which one of the following will NOT occur during water intoxication

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

Question 22

Which of the following is NOT a source of water input

A)fluid intake
B)ingested food
C)osmotic diuresis
D)metabolic production

Question 23

Which of these statements is the best description of the role of angiotensin II

A)It increases Na⁺ reabsorption by stimulating aldosterone secretion.
B)It suppresses the thirst centre at the brain.
C)It is activated when ECF volume and arterial blood pressure are increased.
D)It decreases Na⁺ reabsorption by inhibiting the secretion of vasopressin.

Question 24

Which of these events 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.
D)More K⁺ is secreted by the renal tubules.

Question 25

Which statement does NOT apply to metabolic water

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

Question 26

Which ion has the greatest concentration in the cytoplasm

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

Question 27

Which of these statements does NOT refer to 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.
D)It gives rise to polyuria.

Question 28

Which of these statements does NOT apply to an individual who is overhydrated

A)H₂Oa. will move by osmosis into the cells.
B)Both the ECF and the ICF compartments will be hypertonic after the fluid shift has occurred.
C)Symptoms might include confusion, headache, lethargy, weakness, and oedema.
D)Secretion of vasopressin will be inhibited.

Question 29

What is the importance of regulating ECF osmolarity

A)It helps maintain blood pressure.
B)It prevents the urine from becoming too concentrated.
C)It prevents fluid shifts between the cells and the extracellular fluid.
D)It prevents spontaneous depolarization of nerve and muscle cell membranes because of shifts in Na⁺ balance.

Question 30

Which of these statements refers to osmolarity

A)A hypertonic solution has a higher concentration of solutes and a lower concentration of H₂Oa. than an isotonic solution.
B)When the body becomes dehydrated (H₂Oa. deficit), urinary output increases as a compensatory measure.
C)Vasopressin secretion is decreased when a deficit of water develops in the body.
D)Diabetes insipidus often leads to hypotonicity of the body fluids.

Question 31

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

Question 32

Which of these statements does NOT apply to hypotonicity of the body fluids

A)It can occur as a result of diabetes insipidus.
B)It occurs when excess free H₂Oa. is present.
C)Drowsiness, headache, confusion, lethargy, weakness, and oedema are symptoms associated with it.
D)Cells become swollen.

Question 33

Which of these statements describes 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 34

What is the main control for salt balance

A)salt intake
B)salt output in the sweat
C)salt output in the feces
D)salt output in the urine

Question 35

Which of these statements applies to hypotonicity

A)Water enters the cells by osmosis.
B)Its only cause is drinking excess fluid.
C)It is a major consequence of diabetes mellitus, which is a deficiency of vasopressin.
D)It is usually associated with a negative water balance.

Question 36

What is the effect on water when ECF becomes hypertonic

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 37

Which of the following 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 the ICF.

Question 38

What will happen if the osmolarity of ECF 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 39

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 40

Which of these events happens if an individual becomes dehydrated

A)Increased facultative reabsorption of water occurs.
B)Urinary output increases.
C)Vasopressin secretion decreases.
D)The ECF osmolarity becomes hypotonic.

Question 41

Which of these statements does NOT describe pH

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 concentrations in the body fluids are known, even if the H⁺ concentration is unknown.
C)It is lower in arterial blood than in venous blood.
D)The value is higher in an alkaline situation.

Question 42

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 43

Which of these statements does NOT describe normal blood pH

A)It is slightly basic.
B)It is slightly acidic.
C)It falls between 7.35 and 7.45.
D)It has a very narrow normal range.

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

Which of these symptoms is/are associated with acidosis

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

Question 46

Which of these statements does NOT describe chemical buffer systems

A)They minimize changes in the pH of a solution when an acid or a base is added to or removed from the solution.
B)They can act within a fraction of a second to buffer changes in hydrogen ion concentration.
C)The direction of their reaction is determined according to the law of mass action.
D)They promote H⁺ excretion by the kidneys when acidosis is present.

Question 47

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

A)10
B)100
C)1000
D)10000

Question 48

Which of these symptoms 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 49

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)pH = 7.7
D)It is impossible to determine the pH with the information provided.

Question 50

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 will become hypertonic to the ICF.
D)The osmolarities of the ICF and the ECF will drop.

Question 51

Which of these statements does NOT describe pH

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.
D)It can be calculated if the HCO₃- and CO₂ concentrations in the body fluids are known, even if the H⁺ concentration is unknown.

Question 52

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 53

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

Question 54

Which of these situations 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 55

Insensible water loss includes loss ________________________.

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

Question 56

What is the major source of water loss from the body

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

Question 57

Which of these acids 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 58

Hypothalamic osmoreceptors are located nearest which of the following

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

Question 59

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

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

Question 60

Under which of these circumstances is the thirst mechanism NOT invoked

A)when the ECF volume decreases
B)when the plasma osmolarity decreases
C)when hypothalamic osmoreceptors are activated
D)when there is dryness in the mouth

Question 61

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 62

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

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

Question 63

Which of these statements describes chemical buffer systems

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 respond to changes in acid or base levels.

Question 64

Which chemical buffer system buffers primarily against carbonic acid changes

A)bicarbonate
B)protein
C)haemoglobin
D)phosphate

Question 65

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 66

Which of these situations might be a consequence of vomiting of gastric contents

A)abnormal buildup of plasma H⁺
B)abnormal decrease of plasma HCO₃-
C)dehydration and metabolic acidosis
D)dehydration and metabolic alkalosis

Question 67

Which of these statements describes chemical buffer systems

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 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

H⁺ generated from CO₂ at the tissue level is buffered in transit between the tissues and the lungs by primarily which of the following

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

Question 70

Which of these statements does NOT describe the kidneys' response to increased [H⁺] in the body fluids

A)They conserve HCO₃- by reabsorbing more HCO₃- and reducing its excretion in the urine.
B)They secrete more H⁺ to be eliminated in the urine.
C)They secrete more basic phosphate to buffer the H⁺ in the tubular filtrate.

Question 71

Which [HCO₃-]/[CO₂] ratio might exist in this condition

A)40/1
B)20/2
C)20/5
D)15/10

Question 72

Which of these statements does NOT pertain to 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.
D)His kidneys would likely be compensating for this condition.

Question 73

Which of these statements does NOT describe the respiratory mechanism of pH control

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 74

Given the following logarithms, what would be the pH of this patient
Log of 10 = 1.0
Log of 20 = 1.3
Log of 40 = 1.6
PK = 6.1

A)pH = 7.7
B)pH = 7.4
C)pH = 7.1
D)pH = 6.9

Question 75

The first line of defence against this change in [H⁺] is the chemical buffer systems.Which primary buffer system will respond to this change

A)phosphate buffer system
B)NH4+:NH3 buffer system
C)protein buffer system
D)haemoglobin buffer system

Question 76

Which of these conditions would be a cause of metabolic acidosis

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

Question 77

Which of these statements does NOT describe a chemical buffer system

A)It 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)It minimizes changes in the pH of a solution when an acid or a base is added to or removed from the solution.
C)Buffers respond to pH changes in three minutes.
D)It cannot actually eliminate hydrogen ions from the body.

Question 78

What is the primary buffer system in the ECF

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

Question 79

Which of these statements does NOT describe HCO₃- excretion by the kidneys

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)Excretion of HCO₃- increases during alkalosis.

Question 80

Which of these statements describes the respiratory mechanism of pH control

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 body fluids.