Question 1

Which of the following best explains why the intrapleural pressure is always negative relative to atmospheric pressure, and what is its functional significance?

Accepted Answer

It results from the opposing forces of lung recoil and chest wall expansion, creating a partial vacuum that keeps the lungs inflated.

Question 2

A patient presents with a blood pH of 7.25, elevated arterial $$\mathrm{P_{CO_2$}}$$, and normal bicarbonate levels. Which condition is most likely, and what is the primary compensatory mechanism?

Accepted Answer

Respiratory acidosis; compensation by renal retention of $$\mathrm{$$HCO_3$$^-}.$$

Question 3

Which of the following best describes the role of surfactant in the alveoli?

Accepted Answer

It decreases the surface tension of alveolar fluid, preventing alveolar collapse during expiration.

Question 4

A person with chronic bronchitis is likely to experience which of the following physiological changes?

Accepted Answer

Obstruction of airways due to excessive mucus and inflammation, leading to impaired ventilation.

Question 5

Which equation correctly represents Boyle's Law as it applies to pulmonary ventilation?

Accepted Answer

$$P_1V_1 = P_2V_2$$

Question 6

During intense exercise, which of the following changes would most likely facilitate increased oxygen unloading from hemoglobin in systemic tissues?

Accepted Answer

Increased temperature, increased $$\mathrm{P_{CO_2$}}$$, and increased 2,3-BPG.

Question 7

Which of the following best describes the sequence of structures that air passes through from the external environment to the alveoli?

Accepted Answer

Nose → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli

Question 8

Which of the following pressures directly opposes glomerular hydrostatic pressure and thus reduces the net filtration pressure in the renal corpuscle?

Accepted Answer

Capsular hydrostatic pressure

Question 9

A patient with uncontrolled diabetes mellitus is found to have glucose in their urine. Which renal process is most likely overwhelmed in this scenario?

Accepted Answer

Tubular reabsorption

Question 10

Which hormone increases water reabsorption in the collecting ducts of the kidney, and what is its mechanism of action?

Accepted Answer

Antidiuretic hormone (ADH); increases aquaporin insertion into the collecting duct membrane.

Question 11

Which of the following best describes the mechanism by which the kidneys contribute to acid-base balance during chronic respiratory acidosis?

Accepted Answer

By increasing the secretion of hydrogen ions and reabsorbing more bicarbonate ions.

Question 12

Which of the following is a consequence of hypotonic hydration (water intoxication)?

Accepted Answer

Cells swell as water moves into them, potentially causing cerebral edema.

Question 13

Which of the following best explains why sodium is the most important ion in determining extracellular fluid volume?

Accepted Answer

Sodium exerts the greatest osmotic pressure in the extracellular fluid, thus controlling water movement.

Question 14

A patient is found to have proteinuria (protein in the urine). Which of the following is the most likely explanation?

Accepted Answer

Damage to the glomerular filtration membrane, increasing its permeability.

Question 15

Which of the following best describes the effect of increased arterial $$\mathrm{P_{CO_2$}} on $$respiratory rate and depth?

Accepted Answer

It increases respiratory rate and depth via stimulation of central chemoreceptors.

Question 16

Which of the following best describes the mechanism responsible for the medullary osmotic gradient in the kidney?

Accepted Answer

Active transport of sodium and chloride in the ascending limb of the nephron loop, combined with countercurrent flow.

Question 17

Which of the following is a primary function of the respiratory zone of the respiratory system?

Accepted Answer

Gas exchange between air and blood.

Question 18

Which of the following best describes renal clearance, and what does a clearance value greater than zero but less than the glomerular filtration rate (GFR) indicate?

Accepted Answer

Renal clearance is the volume of plasma cleared of a substance per unit time; a value less than GFR indicates the substance is filtered and partially reabsorbed.

Question 19

Which of the following is a protective mechanism of the respiratory system that helps prevent infection?

Accepted Answer

The mucociliary escalator, which traps and moves particles out of the airways.

Study Notes: The Respiratory System, Urinary System, and Acid-Base Balance

Guida di studio - Domande di pratica

Study guide - Flashcard