Deck 20: Fluid, Electrolyte, and Acidbase Homeostasis

Question 1

Which is a hormone that regulates the extent of renal Na⁺ reabsorption?

A) aldosterone
B) angiotensin
C) somatomedin
D) calcitonin
E) endothelin

Answer 1

A

Question 2

Identify the true statement about water intoxication.

A) It causes significant shrinkage of cells.
B) It is a result of excessive water consumption.
C) It is a result of a significant increase in Na⁺ concentration.
D) It leads to reduced water content in the intracellular fluid.
E) It promotes the secretion of antidiuretic hormone.

Answer 2

B

Question 3

The production of which hormone triggers the thirst center in the hypothalamus when the body is dehydrated?

A) gonadotropin releasing hormone II
B) chorionic gonadotropin
C) angiotensin II
D) insulin-like growth factor I
E) luteinizing hormone

Answer 3

C

Question 4

How does antidiuretic hormone regulate water content in the body?

A) It triggers an increase in the activity of baroreceptors in blood vessels.
B) It inhibits signal transmission by the atrial volume receptors.
C) It increases the permeability of the distal tubules and collecting ducts of the kidneys.
D) It activates the renin-angiotensin-aldosterone pathway in the kidneys.
E) It inhibits the production of hepcidin to prevent the process of ion transport between cells.

Question 5

Identify the true statement about water content in the body.

A) Men have less water content in their bodies than women.
B) Infants have the lowest percentage of water content in their bodies.
C) Obese people have proportionally less water content than leaner people.
D) People suffering from edema have less water content than normal people.
E) People with high total body mass have less percentage of water than people with low total body mass.

Question 6

Identify the true statement about aldosterone production.

A) It decreases when blood pressure decreases.
B) It increases when the plasma has high levels of Ca⁺.
C) It increases when blood osmolarity decreases.
D) It decreases when renin levels decline.
E) It decreases when the plasma has a low Na⁺ level.

Question 7

The hormone primarily responsible for the regulation of water loss is

A) erythropoietin
B) gastrin
C) atriopeptin
D) oxytocin
E) vasopressin

Question 8

Antidiuretic hormone's influence on the renal cells causes osmosis of water molecules from the renal fluid to the renal cells and then to the blood stream. This leads to

A) an increase in blood osmolarity
B) an increase in blood volume
C) the production of a large volume of diluted urine
D) a sudden drop in blood pressure
E) the activation of the thirst center in the hypothalamus

Question 9

Water _____ is known to cause swelling of the brain's neurons that can result in mental confusion, seizures, coma, and death.

Question 10

When is metabolic water produced in the body?

A) during the process of intravascular clotting
B) when electrons are accepted by oxygen during aerobic respiration
C) when inorganic compounds dissociate into ions
D) during the process of glomerular filtration
E) when solute exchange takes place between the synovial fluid and the interstitial fluid

Question 11

An increase in which of the following stimulates the thirst center in the hypothalamus?

A) the blood volume
B) the release of renin from kidneys
C) the production of metabolic water
D) the activity of atrial volume receptors
E) the activity of baroreceptors in blood vessels

Question 12

One of the processes by which the human body loses water is

A) agglutination
B) transfusion
C) digestion
D) perspiration
E) inflammation

Question 13

When the human body is dehydrated, there will be

A) a decrease in the activity of osmoreceptors
B) diffusion of water from cells into the interstitial spaces
C) an increase in the osmolarity of body fluids
D) a decrease in solute concentration
E) an increase in blood pressure

Question 14

What happens when a person with increased blood volume fails to secrete atrial natriuretic peptide (ANP)?

A) blood pressure decreases
B) osmolarity of blood increases
C) Na⁺ reabsorption increases
D) expulsion of excess na through urine is inhibited
E) loss of water through urine is hindered

Question 15

The shape and size of a cell remain unaffected under normal conditions because

A) extracellular fluid has a higher concentration of Na⁺
B) extracellular fluid has higher osmolarity than intracellular fluid
C) intracellular fluid and extracellular fluid have the same osmolarity
D) intracellular fluid has a higher osmolarity than extracellular fluid
E) intracellular fluid and extracellular fluid have the same components

Question 16

The fluid present within the cells of the human body is called

A) cytosol
B) plasma
C) endolymph
D) intrapleural fluid
E) vitreous humor

Question 17

What role does antidiuretic hormone play in the regulation of Na⁺ concentration in the body?

A) It deactivates aquaporin-2 proteins in the renal cells.
B) It inhibits osmoreceptors in the hypothalamus.
C) It makes the distal tubules and collecting ducts less permeable.
D) It activates the neurons that detect dryness in the mouth.
E) It promotes water reabsorption into the body.

Question 18

Where are blood vessel walls thin enough to allow exchange of water and solutes between plasma and the interstitial fluid?

A) arterioles
B) alveoli
C) arteries
D) veins
E) capillaries

Question 19

The amount of metabolic water produced is inversely proportional to the amount of adenosine triphosphate (ATP) produced during anaerobic respiration.

Question 20

How would you treat a person with high blood pressure and excess plasma sodium concentration especially when he or she does not exhibit any symptoms of dehydration?

A) by providing calcium supplements
B) by starting the person on thrombolytic agents
C) by administering vasopressin
D) by administering an aldosterone antagonist
E) by starting the person on intravenous heparin

Question 21

A buffer system converts strong acids and strong bases into weak acids and weak bases by removing H⁺ ions from body fluids.

Question 22

Which is the most important regulator of Ca²⁺ concentration in plasma?

A) antidiuretic hormone
B) parathyroid hormone
C) aldosterone
D) vasopressin
E) luteinizing hormone

Question 23

Why does the interstitial fluid have a low concentration of protein anions?

A) due to the impermeability of the capillary membranes to the plasma proteins
B) due to the low affinity of the interstitial fluid to the protein anions
C) due to the hypertonicity of the intracellular fluid
D) due to the inactivation of the protein channels between the cells and the interstitial fluid
E) due to the acidic nature of the interstitial fluid

Question 24

What is the normal concentration of unattached Ca²⁺ in the plasma?

A) 95-105 mEq/liter
B) 3.0- 4.0 mEq/liter
C) 22-26 mEq/liter
D) 4.5-5.5 mEq/liter
E) 136-148 mEq/liter

Question 25

Which of the following is a function of parathyroid hormone?

A) Increasing bone resorption
B) decreasing Ca²⁺ reabsorption
C) decreasing calcitriol production
D) inhibiting the activity of osteoclasts
E) accelerating Ca²⁺ deposition into bones

Question 26

What is the normal plasma Na⁺ concentration?

A) 30-50 mEq/liter
B) 220-280 mEq/liter
C) 100-130 mEq/liter
D) 56-86 mEq/liter
E) 136-148 mEq/liter

Question 27

What happens when the plasma concentration of Na⁺ increases?

A) blood osmolarity decreases
B) antidiuretic hormone is synthesized
C) atrial natriuretic peptide production increases
D) aldosterone production is initiated
E) blood pressure decreases

Question 28

The concentration of K⁺ is higher in the extracellular fluid than the intracellular fluid.

Question 29

What is the function of K⁺ ion in the body?

A) it helps increase the acidity of body fluids
B) it helps establish the resting membrane potential
C) it helps in the secretion of aldosterone
D) it helps maintain a hypotonic intracellular fluid
E) it helps in the depolarization of action potentials

Question 30

One of the functions of Mg²⁺ in the body is

A) maintaining normal neuromuscular activity
B) inhibiting synaptic transmissions
C) inhibiting the secretion of parathyroid hormone
D) regulating aldosterone production
E) deactivating the sodium-potassium pump

Question 31

The kidneys increase urinary excretion of Mg²⁺ in response to

A) low plasma levels of Ca²⁺
B) low plasma levels of Mg²⁺
C) decrease in extracellular fluid volume
D) decrease in parathyroid hormone
E) low pH of the blood

Question 32

What triggers the body to retain excess amounts of sodium and water?

A) adrenal insufficiency
B) water intoxication
C) hypovolemia
D) hyperaldosteronism
E) hyperkalemia

Question 33

Why do the solutions used in oral rehydration therapy include a small amount of table salt?

A) to prevent excessive water retention by the kidneys
B) to prevent water intoxication
C) to inhibit intravascular clotting
D) to inhibit the activity of atrial volume receptors
E) to prevent inflammation of body tissues

Question 34

What is a function of calcitonin?

A) increases production of calcitriol
B) activates the renin-angiotensin-aldosterone pathway
C) deactivates the neurons in the mouth that detect dryness
D) accelerates Ca²⁺ deposition into bones
E) increases blood Ca²⁺ levels

Question 35

Which is the most abundant cation in the extracellular fluid?

A) Ca⁺
B) Na⁺
C) Mg²⁺
D) K⁺
E) P³⁺

Question 36

Which two hormones help regulate the level of HPO₄²⁻ in the plasma?

A) aldosterone and atrial natriuretic peptide
B) aldosterone and angiotensin II
C) parathyroid hormone and calcitriol
D) parathyroid hormone and calcitonin
E) antidiuretic hormone and calcitriol

Question 37

By affecting the repolarization phase of action potentials, hyperkalemia is known to cause

A) loss in the functioning of the late distal tubules
B) depolarization of action potentials
C) sodium and water retention
D) water intoxication
E) ventricular fibrillation

Question 38

What is the most likely outcome when a person consumes a salty meal?

A) Solute concentration in the extracellular fluid is likely to increase.
B) The synthesis of antidiuretic hormone is likely to be inhibited.
C) Aldosterone production in the body is likely to increase.
D) Extracellular fluid is likely to become hypotonic.
E) Cells in the body are likely to swell.

Question 39

Identify the true statement about bicarbonate ions (HCO₃⁻).

A) Normal plasma HCO₃⁻ concentration is 23-27 mEq/liter in systemic arterial blood.
B) Their concentration increases as carbon dioxide is exhaled.
C) Their concentration increases as blood flows through systemic capillaries.
D) No HCO₃⁻ is found in the intracellular fluid.
E) Their exchange with Cl^- helps maintain the correct balance of cations in the intracellular fluid and the extracellular fluid.

Question 40

One of the functions of the ions present in the body fluids is

A) acting as cofactors for optimal activity of enzymes
B) promoting inflammation during allergic reactions
C) decreasing membrane permeability to fluids
D) increasing the alkalinity of extracellular fluids
E) inhibiting the baroreceptors in blood vessels

Question 41

If the negative feedback regulation of blood pH by the respiratory system is defective when the blood pH is low, what is most likely to happen?

A) more CO₂ will be exhaled
B) the diaphragm and other respiratory muscles will relax
C) dorsal respiratory group in the medulla oblongata will be stimulated
D) the rate of blood flow in the body will increase
E) the concentration of oxygen in blood will decrease

Question 42

What is a function of the carboxyl group of the protein buffer system?

A) It helps convert CO to CO₂ to prevent carbon monoxide poisoning.
B) It helps form carbonic acid for the carbonic acid-bicarbonate buffer system.
C) It releases CO₂ for the purpose of expiration.
D) It combines with H⁺ to reduce the pH of the blood.
E) It releases H⁺ when the pH of the blood increases.

Question 43

One of the effects of an increase in blood acidity is

A) the relaxation of the diaphragm and other respiratory muscles
B) minimal expiration of CO₂
C) the stimulation of the dorsal respiratory group
D) a decrease in the rate of ventilation
E) a decrease in urination frequency

Question 44

Under what condition should a medical practitioner perform respiratory compensation on a patient?

A) altered blood pH
B) alveolar wall disintegration
C) Ca²⁺ deficiency
D) atelectasis of the lungs
E) ventilation-perfusion mismatch

Question 45

The H⁺ secreted into the tubular fluid of the late distal tubule and collecting duct are buffered by

A) NH₃ and HCO₃⁻
B) NH₃ and HPO₄²⁻
C) HCO₃⁻ and H₂PO₄^-
D) HPO₄²⁻ and NH₄⁺
E) H₂PO₄⁻ and HPO₄²⁻

Question 46

Respiratory acidosis occurs when the partial pressure of

A) CO₂ in the systemic arterial blood exceeds 45 mmHg
B) CO₂ in the systemic arterial blood falls below 35 mmHg
C) O₂ the systemic arterial blood exceeds 120 mmHg
D) CO in the systemic arterial blood exceeds 22 mmHg
E) O₂ in the systemic arterial blood falls below 60 mmHg

Question 47

Which of the following scenarios would likely cause a metabolic alkalosis?

A) high altitude sickness
B) severe diarrhea
C) excessive vomiting
D) emphysema

Question 48

_____ _____ is a condition in which the systemic arterial blood HCO₃⁻ concentration is above 26 mEq/liter.

Question 49

When is the carbonic acid-bicarbonate buffer system ineffective against drastic pH changes in the body?

A) when there is an excess of CO₂ in the blood
B) when there is an excess of O₂ in the blood
C) during carbon monoxide poisoning
D) during atelectasis
E) when air enters the pleural cavity of the lungs

Question 50

The phosphate buffer system consist of

A) H₃PO₄ and P₂O₇^4-
B) PO₄^3- and HPO₄^2-
C) H₂PO₄⁻ and HPO₄²⁻
D) P₄O₁₀ and HPO₂
E) H₃PO₄ and H₃PO₃

Question 51

Identify the reaction where a weak acid buffers a base.

A) OH⁻ + H₂PO₄ $\rightarrow$ H₂O + HPO₄²⁻
B) H⁺ + HPO₄²⁻ $\rightarrow$ H₂PO₄⁻
C) H⁺ + HCO₃⁻ $\rightarrow$ H₂CO₃
D) H₂CO₃ $\rightarrow$ H⁺ + HCO₃^-
E) R-NH₂ + H⁺ $\rightarrow$ R-NH₃⁺

Question 52

In the process of secretion of H⁺ by the intercalated cells in the late distal tubule and collecting duct, what would happen if Cl⁻/HCO₃⁻ antiporters are absent?

A) HCO₃^- will accumulate in the intercalated cells
B) H⁺ secretion by the intercalated cells will be inhibited
C) CO₂ and H₂O will accumulate in the intercalated cells
D) The proton pumps will secrete both H⁺ and HCO₃^-
E) Na⁺ resorption will be inhibited

Question 53

_____ is the physiological response that normalizes arterial blood pH in the case of an acid-base imbalance.

Question 54

_____ is a condition in which blood pH is higher than 7.45.

Question 55

Respiratory alkalosis is a condition in which the partial pressure of CO₂ in the systemic arterial blood

A) exceeds 60 mmHg
B) drops below 22 mEq/liter
C) exceeds 26 mEq/liter
D) falls below 35 mmHg
E) is approximately 120 mmHg

Question 56

One of the physiological effects commonly associated with severe acidosis is

A) disorientation
B) chest angina
C) breathlessness
D) convulsions
E) muscle spasms

Question 57

How do you treat metabolic alkalosis?

A) by providing solute-free oral rehydration therapy
B) by providing ventilation therapy
C) by inhaling and exhaling into a paper bag for a short period
D) by performing respiratory compensation through hyperventilation
E) by giving fluid solutions to correct electrolyte deficiencies

Question 58

Since H₂CO₃ can be eliminated by exhaling CO₂, it is called a/an _____ _____.

Question 59

What is likely to happen if renal compensation fails to occur during respiratory alkalosis?

A) reduced excretion of H⁺ ions
B) excessive reabsorption of HCO₃⁻
C) water intoxication
D) enhanced ventilation-perfusion mismatch
E) hypoventilation

Question 60

Identify the equation that correctly represents that protein buffer system.

A) H⁺ + HPO₄²⁻ -> H₂PO₄⁻
B) R-NH₂ + H⁺ -> R-NH₃⁺
C) H₂CO₃ -> H⁺ + HCO₃^-

Question 61

The relationship between pH and the concentrations of the acid and base components of a buffer system is provided by the _____-_____ equation.

Question 62

Respiratory alkalosis is likely to occur in a person

A) at an altitude of 5,000 ft
B) at an altitude of 20,000 ft
C) in the supine position
D) engaging in deep-sea diving
E) engaging in jogging