Review Questions

DIRECTIONS: Each of the numbered items or incomplete statements in this section is followed by an answer or by completions of the statement. Select the ONE lettered answer or completion that is BEST in each case.

1. Which of the following best characterizes the pulmonary circulation?

Flow Pressure Resistance Compliance

(A) Low High Low High

(B) High Low High Low

(C) Low Low Low High

(D) High Low High High

(E) High Low Low High

2. Pulmonary vascular resistance is decreased

(A) At low lung volumes

(B) By breathing low oxygen

(C) At high lung volumes

(D) With increased pulmonary arterial pressure

3. In healthy individuals, the pulmonary and systemic circulations have the same

(A) Mean pressure

(B) Vascular resistance

(C) Compliance

(D) Flow per minute

(E) Capillary blood volume

4. The effect of gravity on the pulmonary circulation in an upright individual will cause

(A) Blood flow to be the greatest in the middle of the lung

(B) Capillary pressure to be greater at the base of the lung compared with the apex

(C) C) Alveolar pressure to be greater than capillary pressure at the base of the lung

(D) Lower vascular resistance at the apex of the lung compared with the base

(E) Venous pressure to be greater than alveolar pressure at the apex

5. A patient lying on his back and breathing normally has a mean left atrial pressure of 7 cm H2O, a mean pulmonary arterial pressure of 15 cm H2O; a cardiac output of 4 L/min, and an anteroposterior chest depth of 15 cm, measured at the xiphoid process. Most of his lung is perfused under which of the following conditions?

6. Lowering pulmonary venous pressure will have the greatest effect on regional blood flow in

7. Which of the following best characterizes alveolar ventilation and blood flow at the base, compared with the apex, of the lungs of a healthy standing person?

VentilationVentilation Blood flow perfusion ratio

(A) Higher Higher Lower

(B) Lower Higher Higher

(C) Lower Lower Lower

(D) Higher Lower Higher

(E) Lower Lower Higher

8. The regional changes seen in ventilation and perfusion in lungs of a

(continued)

healthy standing individual are largely brought about by

(A) Differences in alveolar surface tension

(B) The pyramidal shape of the lung

(C) The effects of gravity

(D) Differences in lung compliance

(E) Differences in lung elastic recoil 9. Regional differences in ventilationperfusion ratios affect gas tensions in the pulmonary blood. Which of the following best describes the gas tensions in the blood leaving the alveolar capillaries of a healthy standing individual?

02 tension (P02) C02 tension (PC02)

(A) Lowest at base Highest at apex

(B) Highest at base Lowest at base

(C) Highest at apex Lowest at apex

(D) Highest at apex Lowest at base

(E) Lowest at base Lowest at base 10. A 26-year-old patient has a cardiac output of 5 L/min and mean pulmonary arterial and left atrial pressures of 20 and 5 mm Hg, respectively. What is her pulmonary vascular resistance?

11. The apex of the lungs of a 21-year-old subject is 20 cm above the heart. What pressure (in mm Hg) must his right ventricle produce to pump blood to the top of the lungs?

12. A 32-year-old patient has a pulmonary vascular resistance of 4 mm Hg/L per minute and a cardiac output of 5 L/min. What is her driving pressure for moving blood through the pulmonary circulation?

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Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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