Deck 25: Structure and Function of the Pulmonary System

Question 1

The _____ is the maximum amount of gas that can be displaced (expired) from the lung.

A) vital capacity
B) total lung capacity
C) functional capacity
D) residual volume

Answer 1

vital capacity

Question 2

After entering a room of chemical fog, a 20-year-old male cannot stop sneezing. Which of the following structures is primarily responsible for his sneezing?

A) Upper respiratory tract mucosa
B) Irritant receptors in the trachea and large airways
C) Irritant receptors in the nostrils
D) Nasal hairs and turbinates

Answer 2

Irritant receptors in the nostrils

Question 3

All of the following may be found in the walls of the respiratory bronchi except:

A) smooth muscle.
B) surfactant-producing glands.
C) goblet cells.
D) ciliated cells.

Answer 3

surfactant-producing glands.

Question 4

The receptors that respond to increased pulmonary capillary pressure are called:

A) irritant receptors.
B) chemoreceptors.
C) stretch receptors.
D) J receptors.

Question 5

The pleural membranes are examples of _____ membranes.

A) mucous
B) serous
C) synovial
D) peritoneal

Question 6

During passive inspiration, muscular contraction of the diaphragm causes air to move into the lung. The mechanisms that drive air movement during passive inspiration are:

A) a decrease in intraalveolar pressure and lifting of the rib cage.
B) a decrease in the size of the thorax and alveolar expansion.
C) an increase in the size of the thorax and a decrease in intrapleural pressure.
D) an increase in atmospheric pressure and intrapleural pressure.

Question 7

The pressure required to inflate an alveolus is inversely related to:

A) wall thickness.
B) surface tension.
C) minute volume.
D) alveolar radius.

Question 8

Diffusion of respiratory gases takes place at the membrane between the:

A) alveolar ducts and lymphatic capillaries.
B) type I alveolar cells and pulmonary capillaries.
C) type I and type II alveolar cells.
D) type II alveolar cells and pulmonary venules.

Question 9

A 42-year-old male was involved in a motor vehicle accident during which he suffered a severe head injury. He died shortly after the accident from loss of respiration. The area of the brain most likely involved is the:

A) cerebral cortex.
B) thalamus.
C) basal ganglia.
D) brain stem.

Question 10

If an individual with respiratory difficulty were retaining too much carbon dioxide, which of the following compensatory responses would be initiated?

A) Increase in respiratory rate
B) Decrease in ventilation rate
C) Increase in tidal volume
D) Vasodilation of the pulmonary arterioles

Question 11

_____ are receptors in the lung that decrease ventilatory rate and volume when stimulated.

A) Carbon dioxide receptors
B) Baroreceptors
C) Stretch receptors
D) Chemoreceptors

Question 12

If an individual with respiratory difficulty was retaining too much carbon dioxide, which of the following receptors would be stimulated in an attempt to maintain a normal homeostatic state?

A) Irritant receptors
B) Stretch receptors
C) Peripheral chemoreceptors
D) Central chemoreceptors

Question 13

The lung receives parasympathetic innervation by the _____ nerve.

A) vagus
B) phrenic
C) brachial
D) pectoral

Question 14

The primary function of the pulmonary system is best described as the:

A) intake and expelling of air.
B) exchange of gases between the environment and blood.
C) movement of blood into and out of the capillaries.
D) principle mechanism for cooling of the heart.

Question 15

The slit-shaped space between the true vocal cords forms the:

A) glottis.
B) epiglottis.
C) larynx.
D) carina.

Question 16

Students in a histology class are assigned to identify regions of the lung. The slide shows a basement membrane, capillary lumen, and macrophages. They are looking at the:

A) trachea.
B) bronchioles.
C) alveoli.
D) bronchus.

Question 17

The movement of blood into and out of the capillary beds of the lungs to the body organs and tissues is called:

A) perfusion.
B) ventilation.
C) diffusion.
D) active transport.

Question 18

The nasopharynx is lined with a ciliated mucosal membrane with a highly vascular blood supply. One function of the membrane is to:

A) absorb air.
B) humidify air.
C) cool air.
D) exchange gases.

Question 19

Which of the following volumes represents an average total lung capacity for a healthy adult?

A) 3000 ml
B) 4000 ml
C) 5000 ml
D) 6000 ml

Question 20

A newborn is in respiratory distress and requires ventilation. Tests reveal that he does not produce surfactant due to the absence of:

A) type I alveolar cells.
B) type II alveolar cells.
C) alveolar macrophages.
D) goblet cells.

Question 21

An 80-year-old male presents to his physician complaining of difficulty breathing. Pulmonary function tests reveal that he has increased residual volume. The most likely cause of this disorder is _____ in lung compliance.

A) an increase
B) a decrease
C) no change
D) an absence

Question 22

Carbon dioxide is mainly transported in the blood:

A) attached to oxygen.
B) dissolved in red blood cells.
C) combined with albumin.
D) in the form of bicarbonate.

Question 23

At the base of the lungs:

A) alveolar gas pressure exceeds arterial perfusion pressure.
B) arterial perfusion pressure and alveolar gas pressure are less than at the apex.
C) arterial perfusion pressure exceeds alveolar gas pressure.
D) arterial perfusion and alveolar gas pressure are equal.

Question 24

At sea level, the partial pressure of oxygen is approximately:

A) 16%.
B) 21%.
C) 32%.
D) 78%.

Question 25

In a patient with acidosis or a fever, you would expect the oxyhemoglobin dissociation curve to:

A) shift to the right, causing more O₂ to be released to the cells.
B) shift to the left, allowing less O₂ to be released to the cells.
C) shift downward, allowing less O₂ to dissolve in the plasma.
D) shift upward, allowing more O₂ to dissolve in the plasma.

Question 26

Approximately 1000 ml (1 liter) of oxygen is transported to cells each minute. Most of the oxygen is transported:

A) dissolved in the plasma.
B) bound to hemoglobin.
C) in the form of CO₂.
D) as a free-floating molecule.

Question 27

Determine the partial pressure of oxygen in the lung given the following conditions: Percentage of oxygen in air: 20
Barometric pressure: 700 mm Hg

A) 111 mm Hg
B) 124 mm Hg
C) 131 mm Hg
D) 140 mm Hg

Question 28

Which of the following occurs when there is a balance between outward recoil of the chest wall and inward recoil of lungs at rest?

A) FRC is reached.
B) VC is reached.
C) TLC is reached.
D) IC is reached.

Question 29

A consequence of alveolar hypoxia is:

A) reactive vasodilation.
B) local bronchoconstriction.
C) decreased respiratory rate.
D) pulmonary artery vasoconstriction.

Question 30

Alveoli in the apexes of the lungs are _____ than alveoli in the bases.

A) larger
B) more numerous
C) more compliant
D) better perfused

Question 31

Surfactant facilitates alveolar distention and ventilation by:

A) decreasing thoracic compliance.
B) attracting water to the alveolar surface.
C) decreasing surface tension in alveoli.
D) increasing diffusion in alveoli.

Question 32

Under most circumstances, increased work of breathing results in:

A) increased partial pressure of O₂ in the lungs.
B) increased oxygen consumption.
C) decreased PaCO₂.
D) alterations in alveolar perfusion.

Question 33

If a patient's hemoglobin concentration (Hb) is 14 g/100 ml and arterial oxygen saturation (SaO₂) is 98%, what would be his arterial oxygen content? Remember that 1.34 ml O₂ is the maximum amount of oxygen that can be transported per gram of hemoglobin. Hint: O₂ content = (1.34 × Hb) SaO₂.

A) 13.72 ml O₂ per 100 ml blood
B) 18.38 ml O₂ per 100 ml blood
C) 18.76 ml O₂ per 100 ml blood
D) 19.30 ml O₂ per 100 ml blood