What determines the direction of gas movement?

A)Solubility in water
B)partial pressure gradient
C)temperature
D)molecular weight and size of gas molecule

B)partial pressure gradient

When the inspiratory muscles contract

A)the size of the thoracic cavity increases in diameter
B)the size of the thoracic cavity increases in length
C)the volume of the thoracic cavity decreases
D)the size of the thoracic cavity is increased in both length and diameter

C)the volume of the thoracic cavity decreases

The nutrient blood supply of the lungs is provided by what?

A)The pulmonary arteries
B)The aorta
C)The pulmonary veins
D)the bronchial arteries

D)the bronchial arteries

Oxygen and carbon dioxide are exchanged in the lungs and through all cell membranes by what?

A)Active transport
B)Diffusion
C)Filtration
D)Osmosis

B)Diffusion

Which of the following would not normally be treated by 100% oxygen therapy?

A)Anoxia
B)Carbon monoxide poisoning
C)respiratory crisis in an emphysema patient and eupnea
D)eupnea

C)respiratory crisis in an emphysema patient and eupnea
D)eupnea

Most Oxygen carried in the blood is

A)In solution in the plasma
B)Combined with plasma protein
C)Chemically combined with the heme in red blood cells
D)In solution in the red blood cells

C)Chemically combined with the heme in red blood cells

Which of the following has the greatest stimulating effect on the respiratory centers in the brain?

A)Oxygen
B)Carbon dioxide
C)Calcium
D)Willpower

B)Carbon dioxide

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 is correct?

1. Expansion of the victim's lungs is brought by blowing air in at higher than atmospheric pressure
2. During inflation of the lungs, the intrapleural pressure increases
3. This technique will not work if the victim has a hole in the chest wall, even if the lungs are intact
4. Expiration during this procedure depends on the elasticity of the alveolar and thoracic walls

A)All of these
B)1, 2, 4
C)1, 2, 3
D)1, 4

B)1, 2, 4

A baby holding its breath will

A)Have brain cells damaged because of low blood oxygen levels
B)automatically start to breathe again when the carbon dioxide levels in the blood reach a high enough value
C)suffer heart damage because of increased pressure in the ceratoid sinus and aortic arch areas
D)be called a “blue baby”

B)automatically start to breathe again when the carbon dioxide levels in the blood reach a high enough value

Under ordinary circumstances which of the following blood components is of no physiological significance?

A)Biocarbonate
B)Carbaminohemoglobin
C)Nitrogen
D)Chloride

C)Nitrogen

Damage to which of the following would most likely result in cessation of breathing?

A)The pontine respiratory group
B)the ventral respiratory group of the medulla
C)the stretch receptors in the lungs
D)the dorsal respiratory group of the medulla

B)the ventral respiratory group of the medulla

The bulk of carbon dioxide is carried

A)Chemically combined with amino acids of hemoglobin as carbaminohemoglobin in the red blood cells
B)as the ion HCO3- in the plasma after first entering the red blood cell
C)as carbonic acid in the plasma
D)chemically combined with the heme protion of Hb

B)as the ion HCO3- in the plasma after first entering the red blood cell

Trace the route of air from the external nares to the alveolus. Name subdivisions, of organs where applicable, then, differentiate between conducting and respiratory zone structures.

The route of air from the external nares to an alveolus and the organs involved are as follows: conducting zone structures—external nares, nasal cavity, pharynx (nasopharynx, oropharynx, laryngopharynx), larynx, trachea, and right and left primary bronchi, secondary bronchi, tertiary bronchi and successive bronchi orders, bronchioles, and terminal bronchioles; respiratory zone structures—respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli. (pp. 805–816)

a) Why is it important that the trachea is reinforced with cartilage rings?

B) Why is it advantageous that the rings are incomplete posteriorly?

a. The trachea is reinforced with cartilage rings to prevent the trachea from collapsing and to keep the airway patent despite the pressure changes that occur during breathing.

b. The advantage of the rings not being complete posteriorly is that the esophagus is allowed to expand anteriorly during swallowing.

Briefly explain the reasons that men have deeper voices than boys or women.

The adult male larynx as a whole is larger and the vocal cords are longer than those of women or boys. These changes occur at puberty under the influence of rising levels of testosterone. (p. 808)

The lungs are mostly passageways and elastic tissue. a) what is the role of the elastic tissue?
b) of the passageways?

a. The elastic tissue is essential both for normal inspiration and expiration; expiration is almost totally dependent on elastic recoil of the lungs when the inspiratory muscles relax. (p. 819)

b. The passageways are air conduits used to warm, moisten, and transport air into the alveoli, the site of gas exchange. (p. 803)

Describe the functional relationships between volume changes and gas flow into and out of the lungs.

The volume of gas flow to and from the alveoli is directly proportional to the difference in pressure between the external atmosphere and the alveoli. Very small differences in pressure are sufficient to produce large volumes of gas flow. As thoracic volume increases, intrapulmonary pressure decreases, resulting in air flow into the lungs. When the lungs recoil, thoracic volume decreases, causing intrapulmonary pressure to increase, and gases flow out of the lungs. (p. 820)

Discuss how airway resistance, lung compliance, and alveolar surface tension influence pulmonary ventilation.

Pulmonary ventilation, or gas flow into and out of the lungs, relies on the pressure gra-dient between the atmosphere and alveoli, and airway diameter. Given that gas flow in a system is equal to the pressure gradient divided by the resistance, when resistance increases, gas flow decreases, and vice versa. Changes in resistance are related to airway diameter, which is greatest in medium-sized bronchi. Lung compliance is based on two factors: distensibility and alveolar surface tension. Distensibility is the degree of stretch possible in the lung tissue, while alveolar surface tension is related to the collapsing force of water vapor within the alveoli. Surfactant is secreted in the alveoli to optimize surface tension. In terms of lung compliance, the greater the volume increase for a given rise in pressure, the greater the compliance. (pp. 820–821)

a) Differentiate clearly between minute respiratory voloume and alveolar ventilation rate?
b) Which provides a more accurate measure of ventilator efficiency, and why?

a. Minute ventilation is the total amount of gas that flows into and out of the respiratory tract in one minute. Alveolar ventilation rate takes into account the amount of air wasted in dead space areas and provides a measurement of the concentration of fresh gases in the alveoli at a particular time.

b. Alveolar ventilation rate provides a more accurate measure of ventilatory efficiency because it considers only the volume of air actually participating in gas exchange.

State Dalton’s law of partial pressure and Henry’s law

Dalton’s law of partial pressures states that the total pressure exerted by a mixture of gases is the sum of the pressure exerted independently by each gas in the mixture. Henry’s law states that when a mixture of gases is in contact with a liquid, each gas will dissolve in the liquid in proportion to its partial pressure and its solubility in the liquid. (p. 824)

a) Define hyperventilation.
b) If you hyperventilate, do you retain or expel more carbon dioxide?
c) what effect does hyperventilation have on blood pH?

a. Hyperventilation is rapid or deep breathing.
b. Hyperventilation causes and increases the release of carbon dioxide from the blood.
c. Hyperventilation increases blood pH, due to the increased loss of H+ associated with CO2 in the blood.

Describe age-related changes in respiratory function.

Age-related changes include a loss of elasticity in the lungs and a more rigid chest wall. These factors result in a slowly decreasing ability to ventilate the lungs. Accompanying these changes is a decrease in blood oxygen levels and a reduced sensitivity to the stimulating effects of carbon dioxide. (p. 842)

Critical Thinking

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?

Hemoglobin is almost completely (98%) saturated with oxygen in arterial blood at normal conditions. Hence, hyperventilation will increase the oxygen saturation very little, if at all. However, hyperventilation will flush CO2 out of the blood, ending the stimulus to breathe and possibly causing (1) cerebral ischemia due to hypocapnia, and (2) O2 decrease to dangerously low levels, resulting in fainting. (p. 828)

Critical Thinking

A member of the “Blues” gang was rushed into the emergency room after receiving a knife wound in the left side of his thorax. The diagnosis was pneumothorax and a collapsed lung. Explain exactly

(a) Why the lung collapsed, and

(b) why only one lung and not both collapsed.

a. The lung penetrated by the knife collapsed because the intrapleural pressure became equal to the atmospheric pressure, allowing the pleural membranes to separate.

b. Only the penetrated lung collapsed because it is isolated from the remaining mediastinal structures (and the other lung) by the pleural membranes. (p. 817)

Critical Thinking

A surgeon removed three adjacent bronchopulmonary segments from the left 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?

Adjacent bronchopulmonary segments are separated from one another by partitions of dense connective tissue, which no major vessels cross. Therefore, it is possible for a surgeon to dissect adjacent segments away from one another. The only vessels that had to be cauterized were the few main vessels to each bronchopulmonary segment. (p. 814)

Critical Thinking

After 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 during landing. During the flight, the cabin pressure was equivalent to an altitude of 8000 feet. Explain her problem.

Mary Ann is suffering from decompression sickness, brought on by the rapid ascent in the plane. During the week of diving, she accumulated nitrogen gas in her tissues that at normal altitudes leaves her tissues slowly and unnoticed. However, on the flight, cabin pressure decreased quickly enough to allow residual nitrogen gas to leave more rapidly, causing her symptoms. The return to a lower altitude with a higher atmospheric pressure upon landing alleviates her symptoms. (p. 825)