CHAPTER 16: PULMONARY ANATOMY AND PHYSIOLOGY {Urden: Critical Care Nursing, 9th Edition}

C HAPTER 16: P ULMONARY A NATOMY AND
P HYSIOLOGY
Urden: Critical Care Nursing, 9th Edition



MULTIPLE CHOICE


1. Which part of the pulmonary anatom y does most of the work of breathing?
a. Pleura
b. Intercostal muscles
c. Diaphragm
d. Sternocleidomastoid



ANS: C



The main muscle of inhalation is the diaphragm. It is connected to the
sternum, ribs, and vertebrae. During normal, quiet breathing, the
diaphragm does approximatel y 80% of the work of breathing. The most
important of these are the external intercostal muscles, which elevate
the ribs and expand the chest cage outward. The scalene, anterior
serratus, and sternocleidomastoid muscles also participate to elevate
the first two ribs and sternum.



PTS: 1 DIF: Cognitive Level : Remembering REF: p. 413
OBJ: Nursing Process Step: N/A TOP: Pulmonary
MSC: NC LEX: Physiologic Integrit y

,2. Which statement best describes the left bronchus?
a. The left bronchus has a slight angle of 20 to 30 degrees from the
midline.
b. The two mainstem br onchi are structurally and functionall y similar.
c. The left bronchus is slightl y narrower.
d. The bronchi are the end units of the bronchial tree.



ANS: C



The two mainstem bronchi are structurally different. The right
bronchus is wider and angles at 20 to 30 d egrees from the midline. The
right mainstem bronchus is the most common site of aspiration of
foreign objects. The left bronchus is slightl y narrower than the right,
and because of its position above the heart, the left bronchus angles
directl y toward the left lung at approximatel y 45 to 55 degrees from
the midline.



PTS: 1 DIF: Cognitive Level: Understanding REF: p.
415 | p. 416 | Figure 16 -5 OBJ: Nursing Process Step:
N/A TOP: Pulmonary MSC: NC LEX: Physiologic Integrit y



3. What is the most important f unction of t ype I alveolar epithelial cells?
a. They comprise 90% of total alveolar surface in the lungs for gas
exchange.
b. The abilit y to produce, store, and secrete pulmonary surfactant.
c. The abilit y to trap foreign particles for auto digestion.
d. The maintenan ce, repair, and restoration of the mucociliary
escalator.



ANS: A

, Type I alveolar epithelial cells comprise approximatel y 90% of the
total alveolar surface within the lungs. The most important function of
the t ype II cells is their abilit y to produce, sto re, and secrete
pulmonary surfactant.



PTS: 1 DIF: Cognitive Level: Remembering REF: p. 417
OBJ: Nursing Process Step: N/A TOP: Pulmonary
MSC: NC LEX: Physiologic Integrit y



4. Which statement describes the relationship between the pulmonary
circulation and the pulmonary vascular bed?
a. The pulmonary circulation is a high -pressure system with normal
pressures averaging 100/60 to 120/70 mm Hg.
b. Because of the low pulmonary arterial pressures, the right
ventricular wall thickness needs to be only one -third that of the left
ventricle.
c. Pulmonary hypertension is defined as increased pulmonary artery
systolic pressure above 20 mm Hg.
d. The most common cause of pulmonary hypertension is right -sided
heart failure.



ANS: B



Because of low pulmonary artery pressures, rig ht ventricular wall
thickness needs to be onl y approximatel y one -third of left ventricular
wall thickness. Pulmonary hypertension is defined as increased
pressure (pulmonary artery systolic greater than 35 mm Hg and
pulmonary artery mean less than 25 mm Hg at rest or less than 30 mm
Hg with exertion) within the pulmonary arterial system. Pulmonary