538
U N I T 6
Respiratory Function
R E V I EW E X E R C I S E S
1.
Relate the efficiency and work of breathing to
changes in the tidal volume and respiratory rate
observed in persons with:
A.
Decreased lung compliance in fibrotic lung
disease
B.
Increased airway resistance in emphysema.
2.
Use the solubility coefficient for oxygen and the
oxygen-hemoglobin dissociation curve depicted in
Figure 22-17 to answer the following questions:
A.
What is the hemoglobin saturation at a high
altitude in which the barometric pressure is
500 mm Hg (consider oxygen to represent 21%
of the total gases)?
B.
It is usually recommended that the hemoglobin
saturation of persons with chronic lung disease
be maintained at about 89% when they are
receiving supplemental low-flow oxygen. What
would their PO
2
be at this level of hemoglobin
saturation, and what is the rationale for keeping
the PO
2
at this level?
C.
Why are measures of hemoglobin saturation
not necessarily a good measure of the oxygen-
carrying capacity of blood?
D.
What is the oxygen content of a person with
carbon monoxide poisoning who is receiving
100% oxygen at 3 atmospheres pressure in a
hyperbaric chamber? Consider that most of the
person’s hemoglobin is saturated with carbon
dioxide.
3.
Describe the receptor/s (peripheral and central),
afferent pathways, central integration, and efferent
neural pathways that:
■■
The cough reflex protects the lungs from the
accumulation of secretions and from the entry
of irritating and destructive substances; it is
one of the primary defense mechanisms of the
respiratory tract.
■■
Dyspnea is a subjective sensation of difficulty in
breathing that is seen in cardiac, pulmonary, and
neuromuscular disorders. It can present as air
hunger brought about by inadequate ventilation,
labored or difficulty breathing due to weakened
respiratory muscles, or chest tightness that
occurs with bronchoconstriction.
SUMMARY CONCEPTS
(continued)
A.
Determine the tidal volume and respiratory rate
of the minute volume
B.
Participate in the cough reflex
C.
Contribute to the breathlessness that
accompanies intensive exercise and the dyspnea
that accompanies lung disease.
B I B L I O G R A P H Y
Burke NK, Lu-Yuan L. Mechanisms of dyspnea.
Chest.
2010;135(5):1196–1201.
Canning BJ. Afferent nerves regulating the cough reflex: mechanisms
and mediators of cough in disease.
Otolaryngol Clin North Am.
2010;43(1):1–14.
Chroneos ZC, Zvezdana S-C, Shepard VL. Pulmonary surfactant:
an immunological perspective.
Cell Physiol Biochem.
2010;25:13–26.
Crapo RO. Pulmonary function testing.
N Engl J Med.
1994;331:25–30.
DeTroyer A, Kirkwood PA, Wilson TA. Respiratory action of
inspiratory muscles.
Physiol Rev.
2005;85:717–756.
Hall JE.
Guyton and Hall Textbook of Medical Physiology
. 12th ed.
Philadelphia, PA: Saunders Elsevier; 2011:465–523.
Koeppen BM, Stanton BA.
Berne and Levy Physiology
. 6th ed.
Philadelphia, PA: Mosby Elsevier; 2010:417–444.
Lansing RW, Gracely RH, Banzett RD. The multiple dimensions
of dyspnea: review and hypothesis.
Respir Physiol Neurobiol.
2009;167(1):53–60.
Moore KL, Dalley AF, Agur AMR.
Clinically Oriented Anatomy
.
6th ed. Philadelphia, PA: Wolters Kluwer Health/Lippincott
Williams & Wilkins; 2009:107–127.
O’Donnell DE, Banzett RB, Carrieri-Kohlman V, et al.
Pathophysiology of dyspnea in chronic obstructive lung disease: a
roundtable.
Proc Am Thorac Soc.
2007;4(2):145–168.
Prabhakar NR, Peng Y-J. Peripheral chemoreceptors in health and
disease.
J Applied Physiol.
2004;96:359–366.
Rhoades RA, Bell DR.
Medical Physiology: Principles of Clinical
Medicine
. 4th ed. Philadelphia, PA: Wolters Kluwer Health/
Lippincott Williams & Wilkins; 2013: 326–398.
Ross MH, Pawlina W.
Histology: A Text and Atlas
. 6th ed.
Philadelphia, PA: Wolters Kluwer Health/Lippincott Williams &
Wilkins; 2011:664–684.
West JB.
Respiratory Physiology: The Essentials
. 8th ed.
Philadelphia, PA: Wolters Kluwer Health/Lippincott Williams &
Wilkins; 2008.
Porth Essentials Resources
Explore these additional resources to enhance learning
for this chapter:
•
NCLEX-Style Questions and Other Resources
on
,
•
Study Guide for Essentials of Pathophysiology
•
Concepts in Action Animations
•
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