Chapter 17 review questions Flashcards
Level Two Reviewing Concepts
Compare and contrast the terms in each of the following sets:
a. compliance and elastance
b. inspiration, expiration, and ventilation
c. intrapleural pressure and alveolar pressure
d. total pulmonary ventilation and alveolar ventilation
e. type I and type II alveolar cells
f. pulmonary circulation and systemic circulation
(a) Compliance—ability to deform in response to force; elastance—ability to resume original shape after deforming force has been removed.
(b) Ventilation—air exchange between atmosphere and lungs. Inspiration—air movement into lungs. Expiration—air movement out of lungs.
(c) Intrapleural pressure—always subatmospheric (except during forced expiration, when it may become positive); alveolar pressures vary from subatmospheric to above atmospheric.
(d) Total pulmonary ventilation—volume of air entering or leaving airways in a given period of time. Alveolar ventilation—volume of air entering or leaving alveoli in a given period of time.
(e) Type I—thin cells for gas exchange; Type II—synthesize and secrete surfactant. (f)Pulmonary—from right heart to lung and back to left atrium. Systemic—left heart to most tissues and back to right atrium.
List the major paracrines and neurotransmitters that cause bronchoconstriction and bronchodilation. What receptors do theyact through? (muscarinic, nicotinic, alpha, beta1, beta2)
Bronchoconstriction: histamine, leukotrienes, acetylcholine (muscarinic); bronchodilators: carbon dioxide, epinephrine (Beta 2)
Compile the following terms into a map of ventilation. Use up arrows, down arrows, greater than symbols (>) and less than symbols (<) as modifiers. You may add other terms.
abdominal muscles
air flow
contract
diaphragm
expiratory muscles
external intercostals
forced breathing
in, out, from, to
inspiratory muscles
internal intercostals
PA
Patm
Pintrapleural
quiet breathing
relax
scalenes
See Figs. 17.8 and 17.9.
Decide whether each of the following parameters will increase, decrease, or not change in the situations given.
a. airway resistance with bronchodilation
b. intrapleural pressure during inspiration
c. air flow with bronchoconstriction
d. bronchiolar diameter with increased PCO2
e. tidal volume with decreased compliance
f. alveolar pressure during expiration
(a) decrease, (b) decrease, (c) decrease, (d) increase, (e) decrease, (f)increase
Define the following terms: pneumothorax, spirometer, auscultation, hypoventilation, bronchoconstriction, minute volume, partial pressure of a gas.
Pneumothorax—air in the pleural cavity. Spirometer—a device used to measure ventilation. Auscultation—listening for body sounds. Hypoventilation—decreased pulmonary ventilation. Bronchoconstriction—decrease in bronchiole radius. Minute volume—total pulmonary ventilation. Partial pressure of gas—portion of total pressure in a mixture of gases that is contributed by a specific gas.
The cartoon coyote is blowing up a balloon in another attempt to catch the roadrunner. He first breathes in as much air as he can, then blows out all he can into the balloon.
a. The volume of air in the balloon is equal to the ________ of the coyote’s lungs. This volume can be measured directly by measuring the balloon volume or by adding which respiratory volumes together?
b. In 10 years, when the coyote is still chasing the roadrunner, will he still be able to put as much air into the balloon in one breath? Explain.
(a) vital capacity. Sum of tidal volume and expiratory and inspiratory reserve volumes. (b) No, because lung function decreases with age as elastance and compliance diminish.
Match the descriptions to the appropriate phase(s) of ventilation:
a. usually depend(s) on elastic recoil
b. is/are easier when lung compliance decreases
c. is/are driven mainly by positive intrapleural pressure generated by muscular contraction
d. is usually an active process requiring smooth muscle contraction
- inspiration
- expiration
- both inspiration and expiration
- neither
(a) 2, (b) 2, (c) 4, (d) 4
Draw and label a graph showing the PO2 of air in the primary bronchi during one respiratory cycle. (Hint: What parameter goes on each axis?)
x-axis—time; y-axis – PO2 During inspiration, the
of the primary bronchi will increase, as fresh air
(PO2 = 160 mm Hg) replaces the stale air (PO2 = 100 mm Hg). During expiration, the PO2 will decrease, as the oxygen-depleted air exits the alveoli. The curve will vary from 100 mm Hg to 160 mm Hg.
Lung compliance increases but chest wall compliance decreases as we age. In the absence of other changes, would the following parameters increase, decrease, or not change as compliance decreases?
a. work required for breathing
b. ease with which lungs inflate
c. lung elastance
d. airway resistance during inspiration
(a) Work increases. (b) Lungs inflate more easily. (c) Elastance decreases. (d) Airway resistance is not affected.
Will pulmonary surfactant increase, decrease, or not change the following?
a. work required for breathing
b. lung compliance
c. surface tension in the alveoli
(a) decrease, (b) increase, (c) decrease
A student breathes at a rate of 20 breaths/min, with a tidal volume of 300 mL/breath. If his anatomic dead space is 130 mL, calculate his total pulmonary ventilation rate and his alveolar ventilation rate.
Level Three Problem Solving:
A 30-year-old computer programmer has had asthma for 15 years. When she lies down at night, she has spells of wheezing and coughing. Over the years, she has found that she can breathe better if she sleeps sitting nearly upright. Upon examination, her doctor finds that she has an enlarged thorax. Her lungs are overinflated on x-ray. Here are the results of her examination and pulmonary function tests. Use the normal values and abbreviations in Fig. 17.7 to help answer the questions.
(a) 9600 mL/min. (b) Dilating bronchioles reduces airway resistance. The patient is able to force more air out of the lungs on expiration, which increases her ERV and decreases her RV. (c) Respiratory rate is normal, but lung volumes are abnormal. Her high RV is confirmed by the X-ray. In obstructive lung diseases such as asthma, the bronchioles collapse on expiration, trapping air in the lungs and resulting in hyperinflation. Her low IRV accounts for most of the low vital capacity and is to be expected in someone with asthma, where the lungs are already overinflated at the beginning of inspiration. Her higher tidal volume may be the result of the effort she must exert to breathe.
After she was given a bronchodilator, her vital capacity increased to3650 mL.
a. What is her minute volume?
b. Explain the change in vital capacity with bronchodilators.
c. Which other values are abnormal? Can you explain why they might be, given her history and findings?
Expired alveolar air mixes with higher O2 atmospheric air in the anatomic dead space, increasing the PO2 of air leaving the airways.
Alveolar air has an average PO2 of 100 mm Hg, but expired air has an average PO2 of 120 mm Hg. If oxygen moves out of the lungs into the body, why is there more oxygen in the expired air?
Expired alveolar air mixes with higher
O2 atmospheric air in the anatomic dead space, increasing the PO2 of air leaving the airways.
Assume a normal female has a resting tidal volume of 400 mL, a respiratory rate of 13 breaths/min, and an anatomic dead space of 125 mL. When she exercises, which of the following scenarios would be most efficient for increasing her oxygen delivery to the lungs?
a. increase respiratory rate to 20 breaths/min but have no change in tidal volume
b. increase tidal volume to 550 mL but have no change in respiratory rate
c. increase tidal volume to 500 mL and respiratory rate to 15 breaths/min
Which of these scenarios is most likely to occur during exercise in real life?
Resting alveolar ventilation = 3575 mL/min.
Exercising: (a) 5500 mL/min (b) 5525 mL/min (c) 5625 mL/min. Increasing both rate and depth has the largest effect and is what would happen in real life.
