Q&A Hero

Q: Hemoglobin's affinity for CO is 2 times that of its affinity for O2. a. True b. False

Q: When not combined with O2, hemoglobin is referred to as reduced hemoglobin, or deoxyhemoglobin. a. True b. False

Q: The more actively a tissue is metabolizing, the higher the cellular PO2 rises and the lower the cellular PCO2 falls. a. True b. False

Q: Inadequate gas exchange can occur when the thickness of the barrier separating the air and blood is pathologically decreased. a. True b. False

Q: The rate of gas exchange is directly proportional to the surface area across which exchange takes place. a. True b. False

Q: The amount of O2 picked up in the lungs exceeds the amount extracted and used by the tissues. a. True b. False

Q: A difference in partial pressure between the venous blood and the surrounding structures is known as a partial pressure gradient. a. True b. False

Q: An increase in alveolar O2 concentration caused by a mismatched large airflow and small blood flow brings about pulmonary vasodilation. a. True b. False

Q: Because the amount of atmospheric air that reaches the alveoli and is actually available for exchange with blood is more important than the total amount breathed in and out, alveolar ventilation is more important than pulmonary ventilation. a. True b. False

Q: Anatomic dead space greatly affects the efficiency of pulmonary ventilation. a. True b. False

Q: Inspiratory volume is the minimum volume of air remaining in the lungs even after a maximal expiration. a. True b. False

Q: When elastic recoil is decreased, as with asthma, passive expiration may be inadequate to expel the volume of air normally exhaled during quiet breathing. a. True b. False

Q: The tremendous surface tension of pure water is normally counteracted by pulmonary surfactant. a. True b. False

Q: The lungs' elastic behavior results from elastin fibers and alveolar surface tension. a. True b. False

Q: Emphysema is a long-term inflammatory condition of the lower respiratory airways, generally triggered by frequent exposure to irritating cigarette smoke, polluted air, or allergens. a. True b. False

Q: A double-walled, closed sac called the pleural sac separates each lung from the thoracic wall and other surrounding structures. a. True b. False

Q: In addition to the thin, wall-forming Type IV cells, 50% of the alveolar surface epithelium is covered by Type III alveolar cells. a. True b. False

Q: Beyond the larynx, the trachea divides into two main branches, the right and left bronchi. a. True b. False

Q: The term external respiration refers to the entire sequence of events in exchange of O2 and CO2 between the external environment and tissue cells. a. True b. False

Q: What are the two biggest risk factors associated with sudden infant death syndrome? a. stomach sleeping and exposure to nicotine b. side sleeping and exposure to nicotine c. lack of sleep and exposure to carbon monoxide d. exposure to nicotine and alcohol e. exposure to alcohol and ammonia

Q: Hiccups occur when involuntary, spasmodic contractions take place in what muscle? a. chest muscles b. abdominal muscles c. intercostal muscles d. bronchioles e. diaphragm

Q: How much can alveolar ventilation increase during heavy exercise in order to keep pace with the increased demand for O2 uptake and CO2 output? a. 2-fold b. 5-fold c. 10-fold d. 20-fold e. 50-fold

Q: Where are the central chemoreceptors located? a. aortic bodies b. carotid bodies c. lungs d. pons e. medulla

Q: Generation of respiratory rhythm is now known to lie in the: a. medullary respiratory center b. pneumotaxic center c. respiratory modulator d. pre-Btzinger complex e. apneustic center

Q: What is the primary respiratory control center called? a. brain stem control center b. medullary respiratory center c. pulmonary control center d. alveolar modulator e. respiratory modulator

Q: What is the medical term for difficult or labored breathing? a. asthma b. hyperpnea c. dyspnea d. cyanosis e. hypoxia

Q: Most CO2 is transported in the blood as: a. bicarbonate b. bound to hemoglobin c. dissolved in plasma d. carbon monoxide e. water

Q: The influence of CO2 and acid on the release of O2from hemoglobinis known as the: a. Frank effect b. Bohr effect c. Fick's constant d. Boyle's law e. dissociation curve

Q: If hemoglobin levels fall by half, what happens to the O2 carrying capacity of the blood? a. remains the same b. doubles c. drop by 25% d. drops by 50% e. drops by 75%

Q: The most important factor determining the percentage of hemoglobin saturation is the: a. systemic blood pressure b. diastolic blood pressure c. pH of the blood d. PCO2 of the blood e. PO2 of the blood

Q: What percentage of the O2 in the blood is dissolved? a. 0% b. 0.5% c. 1.5% d. 5% e. 15%

Q: What arethe only two places in the entire circulatory system at which gas exchange can take place? a. pulmonary and cardiac capillaries b. pulmonary and the systemic capillaries c. bronchioles and alveoli d. arterial and venous capillaries e. arteries and veins

Q: What are three diseases that increase the thickness of the barrier separating the air and blood? a. pulmonary edema, pulmonary fibrosis, and pneumonia b. pulmonary edema, lung cancer, and asthma c. pulmonary fibrosis, lung cancer, and pneumonia d. pulmonary fibrosis, pneumonia, and asthma e. asthma, bronchitis, emphysema

Q: At the end of inspiration, how much of the air in the alveoli is fresh air? a. about 3% b. about 5% c. about 8% d. about 10% e. about 13%

Q: What is the partial pressure of O2 in atmospheric air? a. 180 mm Hg b. 175 mm Hg c. 170 mm Hg d. 165 mm Hg e. 160 mm Hg

Q: The individual pressure exerted independently by a particular gas within a mixture of gases is known as its: a. passive pressure b. active pressure c. partial pressure d. incomplete pressure e. maximum pressure

Q: Aside from oxygen, atmospheric air mainly consists of: a. nitrogen b. hydrogen c. helium d. neon e. carbon dioxide

Q: How much oxygen does atmospheric air have? a. 15% b. 17% c. 19% d. 21% e. 25%

Q: What is arteriolar and bronchiolar smooth muscle especially sensitive to in their immediate environments? a. O2 levels b. CO2 levels c. surfactant levels d. pH e. glucose

Q: What is the average respiratory rate under resting conditions for most people? a. 7 breaths per minute b. 9 breaths per minute c. 12 breaths per minute d. 16 breaths per minute e. 20 breaths per minute

Q: What is the maximum volume of air that the lungs can hold when healthy? a. 3,600 mL b. 4,700 mL c. 5,700 mL d. 6,500 mL e. 7,500 mL

Q: What is the typical tidal volume under resting conditions for adults? a. 1,500 mL b. 1,200 mL c. 1,000 mL d. 800 mL e. 500 mL

Q: The changes in lung volume that occur with different respiratory efforts can be determined by a: a. breath-o-lizer b. inspirogram c. breathmeter d. spirometer e. exhalogram

Q: During strenuous exercise, what percentage of the body's energy is used for increased ventilation? a. 5% b. 8% c. 10% d. 15% e. 20%

Q: What percentage of the total energy expended by the body is used for quiet breathing? a. 1% b. 3% c. 5% d. 8% e. 10%

Q: Pulmonary surfactant is a complex mixture of lipids and proteins secreted by: a. type I alveolar cells b. type II alveolar cells c. type III alveolar cells d. type I bronchial cells e. type II bronchial cells

Q: What condition is characterized by normal lung tissue being replaced with scar-forming fibrous connective tissue as a result of exposure to asbestos fibers or similar irritants? a. pleurisy b. chronic bronchitis c. emphysema d. pulmonary fibrosis e. asthma

Q: A breakdown of alveolar walls is a characterization of what COPD? a. pleurisy b. chronic bronchitis c. emphysema d. pulmonary edema e. asthma

Q: Profound constriction of the smaller airways caused by trigger-induced spasm of the smooth muscle in the walls of these airways causes what COPD? a. pleurisy b. chronic bronchitis c. emphysema d. pulmonary edema e. asthma

Q: What are the most important expiratory muscles? a. muscles of the abdominal wall b. intercostal muscle c. diaphragm d. lumber muscles e. inner pelvic muscles

Q: What nerve innervates the diaphragm? a. phrenic b. vagus c. intercostal d. T10 e. T8

Q: The abnormal condition of air in the pleural cavity is known as: a. pleurisy b. lung cancer c. pneumothorax d. pulmonary edema e. congestive failure

Q: What is the atmospheric (barometric) pressure at sea level? a. 660 mm Hg b. 700 mm Hg c. 720 mm Hg d. 760 mm Hg e. 860 mm Hg

Q: Approximately how many alveoli do the lungs contain? a. 50 million b. 500 million c. 5 billion d. 50 billion e. 500 billion

Q: What are the two tubes that lead from the pharynx? a. larynx and bronchus b. trachea and larynx c. trachea and esophagus d. nasal tube and esophagus e. bronchus and bronchiole

Q: What happens to angiotensin II in the blood as it passes through the lungs? a. It is converted to aldosterone. b. It is converted to renin. c. It is destroyed. d. It is activated. e. It is inactivated.

Q: What is the average respiratory quotient (RQ) based on the typical American diet? a. 2.5 b. 1.8 c. 1.4 d. 1 e. 0.8

Q: What is the respiratory quotient (RQ)? a. The ratio of CO2 produced to O2 consumed b. The ratio of O2 produced to CO2 consumed c. The ratio of CO2 produced to ATP consumed d. The ratio of O2 produced to ATP consumed e. The ratio of ADP produced to ATP consumed

Q: Where is cellular metabolism carried out within cells? a. endoplasmic reticulum b. mitochondria c. nucleus d. ribosomes e. plasma membrane

Q: Describe the dorsal respiratory group (DRG).

Q: Explain the Bohr effect on the release of O2.

Q: Discuss the net diffusion of O2 and CO2 between the alveoli and tissues.

Q: Discuss Boyle's law and respiratory muscle activity.

Q: Describe the structure and function of the alveoli.

Q: Which number in the figure represents a monocyte?a. 1b. 2c. 3d. 4e. 5

Q: Which number in the figure represents a type II alveolar cell?a. 1b. 2c. 3d. 4e. 5

Q: Which number in the figure represents an alveolar macrophage?a. 1b. 2c. 3d. 4e. 5

Q: Which number in the figure represents a type I alveolar cell?a. 1b. 2c. 3d. 4e. 5

Q: Which number in the figure represents an erythrocyte?a. 1b. 2c. 3d. 4e. 5

Q: If breathing does not resume following apnea, the condition is called __________.

Q: Changes in arterial hydrogen ion concentration cannot influence the __________ chemoreceptors because it does not readily cross the __________ barrier.

Q: The __________ center prevents the inspiratory neurons from being switched off, thus providing an extra boost to the inspiratory drive.

Q: The __________ respiratory group consists mostly of inspiratory neurons whose descending fibers terminate on the motor neurons that supply the inspiratory muscles.

Q: About 30% of the CO2 combines with hemoglobin to form __________.

Q: Factors that affect the affinity between hemoglobin and oxygen include CO2, __________, __________, and 2,3-bisphosphoglycerate.

Q: According to the law of __________, if the concentration of one substance involved in a reversible reaction is increased, the reaction is driven toward the opposite side.

Q: Oxygen is present in the blood in two forms: __________ dissolved and __________ bound to hemoglobin.

Q: The diffusion constant for CO2 is ______ times that of O2 because CO2 is much more soluble in body tissues than O2 is.

Q: As blood passes through the lungs, it picks up __________ and gives up CO2 by diffusion down partial pressure gradients between blood and __________.

Q: The greater the partial pressure of a gas in a liquid, the __________ of that gas is dissolved.