Respiratory System True/False

The respiratory zone is composed of the trachea and the paranasal sinuses.

False

Lung cancer is among the easiest forms of cancer to successfully treat and cure.

False - Lung cancer is the leading cause of cancer death from both men and women in North America, causing more deaths than breast, prostate, and colorectal cancer combined. This is tragic, because lung cancer is largely preventable—nearly 90% of lung cancers are the result of smoking.

Most oxygen is transported in the blood as oxyhemoglobin, while most carbon dioxide is transported as carbaminohemoglobin.

False - Most carbon dioxide (about 70%) is transported as bicarbonate ions in the plasma.

The most prevalent gas in the atmosphere is oxygen.

False - Nitrogen (79%) is the most common gas in the atmosphere.

The dorsal respiratory group is the expiratory center.

False - The DRG stimulates the diaphragm and external intercostal muscles, which are inspiratory muscles.

The respiratory rate increases from birth until adulthood.

False - The respiratory rate is highest in newborns and decreases until adulthood.

Henry's law states that the total pressure exerted by a mixture of gases is the sum of the pressures exerted independently by each gas in the mixture.

False - This is Dalton's law, not Henry's law.

The transpulmonary air pressure is greatest during initial inspiratory events.

False - Transpulmonary pressure is greatest at the start of expiration.

Henry's law states that when a gas is in contact with a liquid, that gas will dissolve in the liquid in proportion to its partial pressure.

True

The bronchial, or respiratory, tree branches approximately 23 times within the lungs.

True

The two lungs differ in shape and size.

True

An increase in temperature of the blood will decrease Hb affinity for O2.

True - An increase in temperature will cause the oxygen-hemoglobin dissociation curve to shift to the right, because an increase in temperature enhances oxygen unloading from the blood.

An increase in carbon dioxide in the blood will cause a slight increase in H+ concentration (drop in pH).

True - As CO2 combines with H2O, carbonic acid is formed in the RBCs. Hb buffers most of the liberated H+, allowing only a slight increase in H+ concentration in the blood.

If intrapulmonary pressure and intrapleural pressure equalize, atelectasis will occur.

True - Atelectasis is lung collapse.

During fetal life the lungs are filled with fluid and all respiratory exchanges are made by the placenta.

True - During fetal development, circulating blood is routed through vascular shunts and largely bypasses the lungs. At birth, the fluid-filled pathway drains and fills with air when the newborn takes its first breath.

Emphysema is distinguished by permanent enlargement of the alveoli.

True - Emphysema is distinguished by permanent enlargement of the alveoli, accompanied by destruction of the alveolar walls.

External respiration refers to gas exchange between the blood and the alveoli.

True - Respiration involves four processes: ventilation, external respiration, gas transport, and internal respiration.

Without the secretions of the type II alveolar cells, the lungs would collapse between breaths.

True - Type II cells produce surfactant, which reduces surface tension.