Chapter 10

Question 1

What is the function of the respiratory system?

Answer 1

The organs of the respiratory system ensure that oxygen enters the body and carbon dioxide leaves the body.

Question 2

Respiration or ventilation includes what two processes?

Answer 2

Ventilation is another term for breathing that includes both inspiration, or inhalation, and expiration, or exhalation. Gas exchange is necessary because the cells of the body carry out cellular respiration to make energy in the form of ATP.

Question 3

What is the function of the nose and nasal cavities?

Answer 3

The two nasal cavities, which contain receptor cells, receive tear ducts from the eyes and communicate with the sinuses. The auditory tube from the middle ear communicates with the nasopharynx.

Question 4

Where are the auditory tubes located? What causes the popping sensation in your ears when you change elevation?

Answer 4

The nose warms and cleanses incoming air. Auditory tubes connected to the nasopharynx also connect to the middle ear. When air pressure in the middle ears equalizes with that of the pharynx, a popping sensation may be heard.

Question 5

What is the function of the pharynx?

Answer 5

The pharynx, a passageway from the nasal cavities and the oral cavities and to the larynx, contains the tonsils. The pharynx takes air from the nose to the larynx and transports food from the oral cavity to the esophagus. If someone swallows and food enters the larynx, coughing occurs to dislodge the food.

Question 6

What is the Heimlich maneuver?

Answer 6

The Heimlich maneuver can be used to dislodge food blocking the airway.

Question 7

What is the function of the larynx? What is the function of the epiglottis?

Answer 7

The epiglottis covers the glottis, an opening to the larynx, which contains the vocal cords. The vocal cords are mucosal folds supported by elastic ligaments. A voice’s high or low pitch is regulated by changing the tension on the vocal cords.

Question 8

Describe the structure and function of the trachea.

Answer 8

The trachea, supported by C-shaped cartilaginous rings, is lined by ciliated cells, which sweep impurities up to the throat. The trachea takes air to the bronchial tree.

Question 9

Describe the relationship among bronchi, bronchioles, and alveoli. What happens during an asthma attack?

Answer 9

Two primary bronchi, which divide into ever-smaller bronchioles, conduct air into and within the lungs. During an asthma attack, the bronchioles constrict. Each bronchiole leads to an elongated space enclosed by air pockets called alveoli.

Question 10

How many lobes does each lung have? What are the pleurae?

Answer 10

The lungs are paired, cone-shaped organs within the thoracic cavity. The right lung has three lobes, while the left has two lobes to allow room for the heart. Each lung is enclosed by pleurae, serous membranes that produce serous fluid.

Question 11

What type of epithelium lines the alveoli? What is the function of the alveoli? What is surfactant?

Answer 11

The alveoli are air sacs lined by squamous epithelium and surrounded by blood capillaries. Alveoli function in gas exchange between air in the alveoli and capillary blood. Premature infants often suffer from infant respiratory distress syndrome due to a lack of surfactant, which lowers the surface tension of water and prevents the alveoli from closing.

Question 12

What are the two phases of ventilation or breathing?

Answer 12

Ventilation, or breathing, has two phases: inspiration, which moves air into the lungs, and expiration, which moves air out of the lungs.
Ventilation is governed by Boyle’s Law, which states that at a constant temperature, the pressure of a given quantity of gas is inversely proportional to its volume.

Question 13

Describe what happens with the diaphragm and intercostal muscles during inspiration. Explain what is meant by the statement: “Humans inhale by negative pressure.”

Answer 13

During inspiration, the diaphragm and external intercostal muscles contract, increasing the volume of the thoracic cavity, which creates a partial vacuum in the lungs, causing air to move into the lungs. Humans inhale by negative pressure.

Question 14

Describe what happens during expiration.

Answer 14

Expiration is the passive phase of breathing. The elastic properties of the thoracic wall and lungs cause them to recoil, moving air out.

Question 15

What activities can occur when expiration is forced?

Answer 15

Maximum inspiratory effort involves muscles of the back, chest, and neck, and it increases the size of the thoracic cavity to larger than normal. Although expiration is normally passive, it can also be forced. This is necessary to sing and to blow out air.

Question 16

Define the following terms: tidal volume, vital capacity, inspiratory and expiratory reserve volume, residual volume.

Answer 16

Tidal Volume - The tidal volume, only about 500 ml, is the small amount of air that moves in and out with each breath when we are relaxed.

Vital Capacity - The maximum amount of air that can be moved in plus the maximum amount that can be moved out during a single breath is called the vital capacity because your life depends on breathing.

Inspiratory and Expiratory Reserve Volume - The reserve volumes are measured during forced inspiration and expiration. The vital capacity is the sum of the tidal, inspiratory reserve, and expiratory reserve volumes.

Residual Volume - Some air always remains in the lungs. This is the residual volume, and it is not useful for gas exchange. Some of inhaled air fills the nasal cavities, trachea, bronchi, and bronchioles, which are not used for gas exchange. They contain dead air space.

Question 17

What part of the brain controls the rhythm of breathing?

Answer 17

Normally adults have a breathing rate of 12 to 20 ventilations per minute. This rhythm is controlled by a respiratory control center located in the medulla oblongata of the brain. It is thought that a faulty respiratory center signal is the cause of sudden infant death syndrome (SIDS). We can voluntarily change our breathing pattern to accommodate various activities.

Question 18

Describe the chemical control of breathing.

Answer 18

Chemoreceptors are sensory receptors in the body that are sensitive to the chemical composition of body fluids. The pH of blood will become more acidic when there is more carbon dioxide in the blood. Two sets of chemoreceptors, carotid and aortic bodies, that are sensitive to pH can cause breathing to speed up.

Question 19

Distinguish between external respiration and internal respiration.

Answer 19

External Respiration
External respiration is the diffusion of CO2 from pulmonary capillaries into alveolar sacs and O2 from alveolar sacs into pulmonary capillaries. CO2 is carried in the body as bicarbonate ions (HCO3–). The enzyme carbonic anhydrase speeds up the breakdown of carbonic acid (H2CO3) in red blood cells. When hemoglobin takes up oxygen, it is called oxyhemoglobin.

Internal Respiration
Internal respiration is the diffusion of O2 from systemic capillaries into tissues and CO2 from tissue fluid into systemic capillaries. When CO2 diffuses into the blood, a small amount is taken up by hemoglobin, forming carbaminohemoglobin (HbCO2).

Question 20

Briefly describe the following upper respiratory tract infections: “strep throat”, sinusitis, otitis media, tonsillitis, laryngitis.

Answer 20

Upper Respiratory Tract Infections
What we call “strep throat” is a bacterial infection caused by
Streptococcus pyogenes. It can be treated with antibiotics. Upper respiratory tract infections also include the following:
Sinusitis
Infection of cranial sinuses. Symptoms include facial pain and postnasal discharge.
Otitis Media
Infection of the middle ear. It can spread by way of the auditory tube to the middle ear.
Tonsillitis
Infection of the tonsils. The tonsils can be removed surgically in a tonsillectomy.
Laryngitis
Infection of the larynx, leading to the inability to speak audibly.

Question 21

Briefly describe the following lower respiratory infections: acute bronchitis, pneumonia, pulmonary tuberculosis.

Answer 21

Lower Respiratory Tract Disorders
Lower respiratory tract disorders include infections, restrictive and obstructive pulmonary disorders, and lung cancer.
Lower Respiratory Infections
Lower respiratory infections include acute bronchitis (infection of the primary and secondary bronchi), pneumonia (infection of the lungs), and pulmonary tuberculosis (infection caused by tubercle bacillus).

Question 22

What are the symptoms of restrictive pulmonary disorders?

Answer 22

Restrictive pulmonary disorders involve a reduction of vital capacity and can be caused by, for example, asbestos, which causes pulmonary fibrosis.

Question 23

Briefly describe the following obstructive pulmonary disorders: chronic bronchitis, emphysema, asthma.

Answer 23

Obstructive pulmonary disorders include chronic bronchitis (inflamed airways) and emphysema (alveolar walls break down and the surface area for gas exchange is reduced). Asthma is a disease of the bronchi and bronchioles that is marked by an unusual sensitivity to specific irritants. Asthma is not curable, but it is treatable by special inhalers, which control inflammation or stop muscle spasms during an attack.

Question 24

What are some of the symptoms of lung cancer?

Answer 24

Lung cancer has surpassed breast cancer as a cause of death in women and follows this sequence of events: thickening of airway cells, loss of cilia, atypical nuclei, tumor, and metastasis. An operation to remove a lobe or a whole lung before metastasis has occurred is called pneumonectomy. Secondhand smoke exposure can also cause lung cancer and lung disease.