The Respiratory System OpenStax Q&A's

Contraction of the external intercostal muscles causes which of the following to occur? The diaphragm moves downward. The rib cage is compressed. The thoracic cavity volume decreases. The ribs and sternum move upward.

the ribs and sternum upward

What is the role of alveolar macrophages? to secrete pulmonary surfactant to secrete antimicrobial proteins to remove pathogens and debris to facilitate gas exchange

to remove pathogens and debris

The pressure difference between the intra-alveolar and intrapleural pressures is called ________. atmospheric pressure pulmonary pressure negative pressure transpulmonary pressure

transpulmonary pressure

The pleura that surrounds the lungs consists of two layers, the ________. visceral and parietal pleurae. mediastinum and parietal pleurae. visceral and mediastinum pleurae. none of the above

visceral and parietal pleurae

A low partial pressure of oxygen promotes hemoglobin binding to carbon dioxide. This is an example of the ________. Haldane effect Bohr effect Dalton's law Henry's law

Haldane effect

Oxyhemoglobin forms by a chemical reaction between which of the following? hemoglobin and carbon dioxide carbonic anhydrase and carbon dioxide hemoglobin and oxygen carbonic anhydrase and oxygen

Hemoglobin and oxygen

Describe what is meant by the term "lung compliance."

Lung compliance refers to the ability of lung tissue to stretch under pressure, which is determined in part by the surface tension of the alveoli and the ability of the connective tissue to stretch. Lung compliance plays a role in determining how much the lungs can change in volume, which in turn helps to determine pressure and air movement.

A section of the lung that receives its own tertiary bronchus is called the ________. bronchopulmonary segment pulmonary lobule interpulmonary segment respiratory segment

bronchopulmonary segment

Which of the following are structural features of the trachea? C-shaped cartilage smooth muscle fibers cilia all of the above

c-shaped cartilage

Which of the following structures separates the lung into lobes? mediastinum fissure root pleura

fissure

Gas moves from an area of ________ partial pressure to an area of ________ partial pressure. low; high low; low high; high high; low

high; low

A decrease in volume leads to a(n) ________ pressure. decrease in equalization of increase in zero

increase in

What is the function of the conchae in the nasal cavity? increase surface area exchange gases maintain surface tension maintain air pressure

increase surface area

Gas exchange that occurs at the level of the tissues is called ________. external respiration interpulmonary respiration internal respiration pulmonary ventilation

internal respiration

The partial pressure of carbon dioxide is 45 mm Hg in the blood and 40 mm Hg in the alveoli. What happens to the carbon dioxide? It diffuses into the blood. It diffuses into the alveoli. The gradient is too small for carbon dioxide to diffuse. It decomposes into carbon and oxygen

it diffuses into the alveoli

The fauces connects which of the following structures to the oropharynx? nasopharynx laryngopharynx nasal cavity oral cavity

oral cavity

Which of the following processes does atmospheric pressure play a role in? pulmonary ventilation production of pulmonary surfactant resistance surface tension

pulmonary ventilation

Which of the following prevents the alveoli from collapsing? residual volume tidal volume expiratory reserve volume inspiratory reserve volume

residual volume

Gas flow decreases as ________ increases. resistance pressure airway diameter friction

resistance

The ________ circulation picks up oxygen for cellular use and drops off carbon dioxide for removal from the body. pulmonary interlobular respiratory bronchial

respiratory

Which of the following structures is not part of the bronchial tree? alveoli bronchi terminal bronchioles respiratory bronchioles

terminal bronchioles

When ventilation is not sufficient, which of the following occurs? The capillary constricts. The capillary dilates. The partial pressure of oxygen in the affected alveolus increases. The bronchioles dilate.

the capillary constricts

Which of the following factors play a role in the oxygen-hemoglobin saturation/dissociation curve? temperature pH BPG all of the above

All of the above

Compare and contrast Dalton's law and Henry's law.

Both Dalton's and Henry's laws describe the behavior of gases. Dalton's law states that any gas in a mixture of gases exerts force as if it were not in a mixture. Henry's law states that gas molecules dissolve in a liquid proportional to their partial pressure.

Compare and contrast adult hemoglobin and fetal hemoglobin.

Both adult and fetal hemoglobin transport oxygen via iron molecules. However, fetal hemoglobin has about a 20-fold greater affinity for oxygen than does adult hemoglobin. This is due to a difference in structure; fetal hemoglobin has two subunits that have a slightly different structure than the subunits of adult hemoglobin.

Describe three ways in which carbon dioxide can be transported.

Carbon dioxide can be transported by three mechanisms: dissolved in plasma, as bicarbonate, or as carbaminohemoglobin. Dissolved in plasma, carbon dioxide molecules simply diffuse into the blood from the tissues. Bicarbonate is created by a chemical reaction that occurs mostly in erythrocytes, joining carbon dioxide and water by carbonic anhydrase, producing carbonic acid, which breaks down into bicarbonate and hydrogen ions. Carbaminohemoglobin is the bound form of hemoglobin and carbon dioxide.

Which of the following occurs during the chloride shift? Chloride is removed from the erythrocyte. Chloride is exchanged for bicarbonate. Bicarbonate is removed from the erythrocyte. Bicarbonate is removed from the blood.

Chloride is exchanged for bicarbonate

Outline the steps involved in quiet breathing.

Quiet breathing occurs at rest and without active thought. During quiet breathing, the diaphragm and external intercostal muscles work at different extents, depending on the situation. For inspiration, the diaphragm contracts, causing the diaphragm to flatten and drop towards the abdominal cavity, helping to expand the thoracic cavity. The external intercostal muscles contract as well, causing the rib cage to expand, and the rib cage and sternum to move outward, also expanding the thoracic cavity. Expansion of the thoracic cavity also causes the lungs to expand, due to the adhesiveness of the pleural fluid. As a result, the pressure within the lungs drops below that of the atmosphere, causing air to rush into the lungs. In contrast, expiration is a passive process. As the diaphragm and intercostal muscles relax, the lungs and thoracic tissues recoil, and the volume of the lungs decreases. This causes the pressure within the lungs to increase above that of the atmosphere, causing air to leave the lungs.

What is respiratory rate and how is it controlled?

Respiratory rate is defined as the number of breaths taken per minute. Respiratory rate is controlled by the respiratory center, located in the medulla oblongata. Conscious thought can alter the normal respiratory rate through control by skeletal muscle, although one cannot consciously stop the rate altogether. A typical resting respiratory rate is about 14 breaths per minute.

Compare and contrast the conducting and respiratory zones.

The conducting zone of the respiratory system includes the organs and structures that are not directly involved in gas exchange, but perform other duties such as providing a passageway for air, trapping and removing debris and pathogens, and warming and humidifying incoming air. Such structures include the nasal cavity, pharynx, larynx, trachea, and most of the bronchial tree. The respiratory zone includes all the organs and structures that are directly involved in gas exchange, including the respiratory bronchioles, alveolar ducts, and alveoli.

A smoker develops damage to several alveoli that then can no longer function. How does this affect gas exchange?

The damaged alveoli will have insufficient ventilation, causing the partial pressure of oxygen in the alveoli to decrease. As a result, the pulmonary capillaries serving these alveoli will constrict, redirecting blood flow to other alveoli that are receiving sufficient ventilation.

If a person sustains an injury to the epiglottis, what would be the physiological result?

The epiglottis is a region of the larynx that is important during the swallowing of food or drink. As a person swallows, the pharynx moves upward and the epiglottis closes over the trachea, preventing food or drink from entering the trachea. If a person's epiglottis were injured, this mechanism would be impaired. As a result, the person may have problems with food or drink entering the trachea, and possibly, the lungs. Over time, this may cause infections such as pneumonia to set in.

Describe the three regions of the pharynx and their functions.

The pharynx has three major regions. The first region is the nasopharynx, which is connected to the posterior nasal cavity and functions as an airway. The second region is the oropharynx, which is continuous with the nasopharynx and is connected to the oral cavity at the fauces. The laryngopharynx is connected to the oropharynx and the esophagus and trachea. Both the oropharynx and laryngopharynx are passageways for air and food and drink.

Describe the relationship between the partial pressure of oxygen and the binding of oxygen to hemoglobin.

The relationship between the partial pressure of oxygen and the binding of hemoglobin to oxygen is described by the oxygen-hemoglobin saturation/dissociation curve. As the partial pressure of oxygen increases, the number of oxygen molecules bound by hemoglobin increases, thereby increasing the saturation of hemoglobin.

Compare and contrast the right and left lungs.

The right and left lungs differ in size and shape to accommodate other organs that encroach on the thoracic region. The right lung consists of three lobes and is shorter than the left lung, due to the position of the liver underneath it. The left lung consist of two lobes and is longer and narrower than the right lung. The left lung has a concave region on the mediastinal surface called the cardiac notch that allows space for the heart.

Why are the pleurae not damaged during normal breathing?

There is a cavity, called the pleural cavity, between the parietal and visceral layers of the pleura. Mesothelial cells produce and secrete pleural fluid into the pleural cavity that acts as a lubricant. Therefore, as you breathe, the pleural fluid prevents the two layers of the pleura from rubbing against each other and causing damage due to friction.

Which of the following anatomical structures is not part of the conducting zone? pharynx nasal cavity alveoli bronchi

alveoli