Question 1

A 4-year-old child accidentally aspirates a small marble with a diameter of 0.8 mm.Where in the lung is the toy most likely to be found?
A)Bronchus
B)Trachea
C)Bronchioles
D)Alveolus

Accepted Answer

The bronchioles are the smallest branches of the bronchial tree and are the most likely place for a small object to become lodged.

Question 2

A 25-year-old woman with asthma is brought to the emergency department because of an acute asthmatic attack.She is using her sternocleidomastoid and internal/external intercostal muscles to breathe.This can be interpreted as:
A)Improved status; no intervention needed
B)Worsening status; intervention needed
C)Normal breathing pattern; no intervention needed
D)Bronchodilation of the airways

Accepted Answer

The use of accessory muscles such as sternocleidomastoid and intercostal muscles is a sign of worsening status in asthma, as the patient is using additional muscles to breathe due to impaired air flow in the lungs. Intervention is needed to help relieve the asthma attack.

Question 3

A 65-year-old woman with a smoking history of 2 packs/day for 30 years has received a diagnosis of chronic obstructive lung disease.She probably has increased mucus viscosity as a result of:
A)Bronchoconstriction.
B)Stimulation of parasympathetic fibers in bronchial glands.
C)Stimulation of the sympathetic nerves.
D)Abnormal breathing pattern.
E)Stimulation of smooth muscles

Accepted Answer

Smoking can stimulate the parasympathetic fibers in bronchial glands, leading to increased mucus production and viscosity. This is one of the contributing factors to the development of chronic obstructive lung disease. Bronchoconstriction, stimulation of sympathetic nerves, abnormal breathing pattern, and stimulation of smooth muscles may also contribute to the development of the disease, but they do not directly increase mucus viscosity.

Question 4

A baby born at 30 weeks of gestation who develops respiratory distress characterized by atelectasis (collapse of the lung)probably suffers from a physiological defect in:
A)Production of surfactant component phosphatidylglycerol.
B)Lack of surfactant components cholesterol and cholesterol esters.
C)Diaphragmatic movement.
D)Surfactant proteins.
E)Clara cell dysfunction.

Accepted Answer

A baby born at 30 weeks of gestation likely suffers from a deficiency in surfactant production, particularly the component phosphatidylglycerol, which is crucial for reducing surface tension in the lungs and preventing atelectasis.

Question 5

A 65-year-old woman with a smoking history of 2 packs/day for 30 years has received a diagnosis of chronic obstructive lung disease.She is obviously using her accessory respiratory muscles for breathing; this behavior is caused by:
A)Decreased work of breathing as a result of airflow obstruction.
B)Increased work of breathing as a result of a dysfunction in the neuromuscular junction.
C)Increased work of breathing as a result of airflow obstruction that necessitates active contraction of the expiratory muscles.
D)Abnormal breathing pattern.
E)Increased work of breathing as a result of airflow obstruction that necessitates active contraction of the inspiratory muscles.

Accepted Answer

The use of accessory respiratory muscles is a compensatory mechanism utilized to overcome airflow obstruction in chronic obstructive lung disease. This requires active contraction of the expiratory muscles to assist with exhalation, resulting in increased work of breathing. Option A is incorrect as decreased work of breathing is not seen in patients with chronic obstructive lung disease. Option B is incorrect as dysfunction in the neuromuscular junction is not the cause of the use of accessory respiratory muscles. Option D is incorrect as abnormal breathing patterns can occur in various conditions, but this does not explain the specific mechanism seen in chronic obstructive lung disease. Option E is incorrect as active contraction of the inspiratory muscles is not needed to overcome airflow obstruction in chronic obstructive lung disease.

Question 6

Surfactant aids in stabilizing the inflation of alveoli through its ability to decrease surface tension.What best describes the mechanism of interdependence,created by the pores of Kohn and canals of Lambert,which is also important in alveolar inflation?
A)Connection of adjacent alveoli and terminal airways to adjacent alveoli
B)Connection of nonrespiratory bronchioles to alveoli
C)Connection of nonrespiratory bronchioles to respiratory bronchioles
D)Connection of adjacent respiratory bronchioles

Accepted Answer

The pores of Kohn and canals of Lambert provide a mechanism of interdependence by connecting adjacent alveoli and terminal airways to adjacent alveoli. This connection allows for equalization of pressure throughout the lungs, which is important in alveolar inflation. Options B-D are incorrect as they do not accurately describe the role of the pores of Kohn and canals of Lambert.

Question 7

Which of the following is the correct proximal-to-distal alignment of the human airway?
A)Trachea $\rightarrow$ bronchi $\rightarrow$ respiratory bronchioles $\rightarrow$ nonrespiratory bronchioles $\rightarrow$ terminal bronchioles $\rightarrow$ alveolar ducts $\rightarrow$ alveolar sacs
B)Trachea $\rightarrow$ bronchi $\rightarrow$ alveolar ducts $\rightarrow$ alveolar sacs $\rightarrow$ bronchioles $\rightarrow$ terminal bronchioles
C)Trachea $\rightarrow$ bronchi $\rightarrow$ nonrespiratory bronchioles $\rightarrow$ terminal bronchioles $\rightarrow$ alveolar sacs $\rightarrow$ alveolar ducts
D)Trachea $\rightarrow$ bronchi $\rightarrow$ nonrespiratory bronchioles $\rightarrow$ respiratory bronchioles $\rightarrow$ terminal bronchioles $\rightarrow$ alveolar ducts $\rightarrow$ alveolar sacs

Accepted Answer

The correct proximal-to-distal alignment of the human airway is trachea → bronchi → nonrespiratory bronchioles → respiratory bronchioles → terminal bronchioles → alveolar ducts → alveolar sacs. Choice D is the only option that follows this order.

Question 8

Like the kidneys,the lungs demonstrate functional unity; that is,each unit is structurally and functionally identical.The basic physiological unit of the lung is the respiratory unit,which consists of:
A)Nonrespiratory and respiratory bronchioles,alveolar ducts,and alveolar sacs.
B)Respiratory bronchioles,alveolar ducts,and alveolar sacs.
C)Bronchi,nonrespiratory bronchioles,and respiratory bronchioles.
D)Conducting airways,alveolar ducts,and alveolar sacs.

Accepted Answer

The respiratory unit of the lung consists of respiratory bronchioles, alveolar ducts, and alveolar sacs. Option A includes nonrespiratory bronchioles, which are not part of the respiratory unit. Option C includes bronchi, which are larger airways and not part of the respiratory unit. Option D includes conducting airways, which are not part of the respiratory unit.

Question 9

Which statement best describes the unique features of the pulmonary circulatory system?
A)It is a dual system that accommodates large volumes of blood at low pressure.Bronchial circulation arises from the aorta to nourish lung tissue,whereas the pulmonary circulation brings deoxygenated blood to the gas-exchanging units.
B)It is a dual system that accommodates large volumes of blood at high pressure.Bronchial circulation arises from the aorta to nourish lung tissue,whereas the pulmonary circulation brings deoxygenated blood to the gas-exchanging units.
C)It is a dual system that accommodates steady,small volumes of blood at low pressure.Bronchial circulation arises from the aorta to nourish lung tissue,whereas the pulmonary circulation brings deoxygenated blood to the gas-exchanging units.
D)It is a dual system that accommodates large volumes of blood at low pressure.Bronchial circulation arises from the right ventricle to nourish lung tissue,whereas the pulmonary circulation brings deoxygenated blood to the gas-exchanging units.

Accepted Answer

The pulmonary circulatory system is unique because it operates at low pressure to accommodate large volumes of blood, and it indeed comprises two parts: the bronchial circulation, which originates from the aorta to supply the lung tissue with oxygenated blood, and the pulmonary circulation, which carries deoxygenated blood from the heart to the lungs for gas exchange.

Question 10

Which respiratory epithelial cell (1)is at maturation essential for survival of premature infants,(2)produces surfactant,(3)differentiates to establish normal cellular architecture during development and repair,and (4)normally occupies <5% of the luminal surface area after birth?
A)Clara cell
B)Type I epithelial cell
C)Type II epithelial cell
D)Goblet cell
E)Kultschitzky cell

Accepted Answer

Type II epithelial cells are essential for the production of surfactant, which is crucial for the maturation and survival of premature infants. They also differentiate to establish normal cellular architecture during development and repair. Goblet cells produce mucus, Clara cells are involved in detoxification, and Kultschitzky cells secrete hormones, but none of these functions match the description given in the question. Additionally, Type I epithelial cells are primarily involved in gas exchange and make up the majority of the luminal surface area, so they also do not fit the description.

Quiz 20: Structure and Function of the Respiratory System

A 4-year-old child accidentally aspirates a small marble with a diameter of 0.8 mm.Where in the lung is the toy most likely to be found?

A 25-year-old woman with asthma is brought to the emergency department because of an acute asthmatic attack.She is using her sternocleidomastoid and internal/external intercostal muscles to breathe.This can be interpreted as:

A 65-year-old woman with a smoking history of 2 packs/day for 30 years has received a diagnosis of chronic obstructive lung disease.She probably has increased mucus viscosity as a result of:

A baby born at 30 weeks of gestation who develops respiratory distress characterized by atelectasis (collapse of the lung) probably suffers from a physiological defect in:

A 65-year-old woman with a smoking history of 2 packs/day for 30 years has received a diagnosis of chronic obstructive lung disease.She is obviously using her accessory respiratory muscles for breathing; this behavior is caused by:

Surfactant aids in stabilizing the inflation of alveoli through its ability to decrease surface tension.What best describes the mechanism of interdependence,created by the pores of Kohn and canals of Lambert,which is also important in alveolar inflation?

Which of the following is the correct proximal-to-distal alignment of the human airway?

Like the kidneys,the lungs demonstrate functional unity; that is,each unit is structurally and functionally identical.The basic physiological unit of the lung is the respiratory unit,which consists of:

Which statement best describes the unique features of the pulmonary circulatory system?

Which respiratory epithelial cell (1) is at maturation essential for survival of premature infants,(2) produces surfactant,(3) differentiates to establish normal cellular architecture during development and repair,and (4) normally occupies <5% of the luminal surface area after birth?