The Respiratory System
Short Answer Essay Questions
Trace the route of air from the nares to an alveolus. Name
subdivisions of organs where applicable, and diﬀerentiate
between conducting and respiratory zone structures.
(a) Why is it important that the trachea is reinforced with
cartilage rings? (b) Why is it advantageous that the rings are
Brieﬂy explain the anatomical “reason” why most men have
deeper voices than boys or women.
±e lungs are mostly passageways and elastic tissue. (a) What is
the role of the elastic tissue? (b) Of the passageways?
Describe the functional relationships between volume changes
and gas ﬂow into and out of the lungs.
Discuss how airway resistance, lung compliance, and alveolar
surface tension inﬂuence pulmonary ventilation.
(a) Diﬀerentiate clearly between minute respiratory volume and
alveolar ventilation rate. (b) Which provides a more accurate
measure of ventilatory eﬃciency, and why?
State Dalton’s law of partial pressures and Henry’s law.
(a) Deﬁne hyperventilation. (b) If you hyperventilate, do you
retain or expel more carbon dioxide? (c) What eﬀect does
hyperventilation have on blood pH?
Describe age-related changes in respiratory function.
Critical Thinking and Clinical Application Questions
Harry, the swimmer with the fastest time on the Springﬁeld
College swim team, routinely hyperventilates before a meet, as
he says, “to sock some more oxygen into my lungs so I can swim
longer without having to breathe.” First of all, what basic fact
about oxygen loading has Harry forgotten (a lapse leading to false
thinking)? Second, how is Harry jeopardizing not only his time
but his life?
A member of the “Blues” gang was rushed into an emergency
room a²er receiving a knife wound in the le² side of his thorax.
±e diagnosis was pneumothorax and a collapsed lung. Explain
exactly (a) why the lung collapsed, and (b) why only one lung
(not both) collapsed.
A surgeon removed three adjacent bronchopulmonary segments
from the le² lung of a patient with TB. Almost half of the lung
was removed, yet there was no severe bleeding, and relatively
few blood vessels had to be cauterized (closed oﬀ). Why was the
surgery so easy to perform?
A²er a week of scuba diving in the Bahamas, Mary Ann boards
an airplane. During her ﬂight home, she develops aching joints,
nausea, and dyspnea, which resolve upon landing. During the
ﬂight, the cabin pressure was equivalent to an altitude of 8000
feet. Explain her problems.
±e nutrient blood supply of the lungs is provided by
the pulmonary veins,
the bronchial arteries.
Oxygen and carbon dioxide are exchanged in the lungs and
through all cell membranes by
Which of the following would not normally be treated by 100%
oxygen therapy? (Choose all that apply.)
respiratory crisis in an emphysema
Most oxygen carried in the blood is
in solution in the plasma,
combined with plasma proteins,
with the heme in red blood cells,
in solution in the red blood
Which of the following has the greatest stimulating eﬀect on the
respiratory centers in the brain?
In mouth-to-mouth artiﬁcial respiration, the rescuer blows air
from his or her own respiratory system into that of the victim.
Which of the following statements are correct?
Expansion of the victim’s lungs is brought about by blowing
air in at higher than atmospheric pressure (positive-pressure
During inﬂation of the lungs, the intrapleural pressure
±is technique will not work if the victim has a hole in the
chest wall, even if the lungs are intact.
Expiration during this procedure depends on the elasticity of
the alveolar and thoracic walls.
all of these,
1, 2, 4,
1, 2, 3,
A baby holding its breath will
have brain cells damaged
because of low blood oxygen levels,
automatically start to
breathe again when the carbon dioxide levels in the blood reach a
high enough value,
suﬀer heart damage because of increased
pressure in the carotid sinus and aortic arch areas,
be called a
Under ordinary circumstances, which of the following blood
components is of no physiological signiﬁcance?
Damage to which of the following would most likely result in
cessation of breathing?
the pontine respiratory group,
ventral respiratory group of the medulla,
the stretch receptors
in the lungs,
the dorsal respiratory group of the medulla.
±e bulk of carbon dioxide is carried
with the amino acids of hemoglobin as carbaminohemoglobin in
the red blood cells,
as the ion HCO
in the plasma a²er ﬁrst
entering the red blood cell,
as carbonic acid in the plasma,
chemically combined with the heme portion of Hb.
Related Clinical Terms
Surgical removal of an
infected pharyngeal tonsil (adenoids).
Adult respiratory distress syndrome (ARDS)
A dangerous lung
condition that can develop a²er severe illness or injury to the
body. Neutrophils leave the body’s capillaries in large numbers
and then secrete chemicals that increase capillary permeability.
±e capillary-rich lungs are heavily aﬀected. As the lungs ﬁll with
ﬂuid, the patient suﬀocates. Even with mechanical ventilation,
ARDS is hard to control and o²en lethal.
shun) (1) Inhaling or drawing something into
the lungs or respiratory passages. Pathological aspiration—
drawing vomit or excessive mucus into the lungs—may occur
when a person is unconscious or anesthetized; turning the head
to one side is preventive. (2) Withdrawing ﬂuid by suction (use
AT T H E C L I N I C