Physio Chp 13 Quiz Flashcards

What is one function of the type II alveolar cells?

a. Production of surfactant

b. Secretion of mucus

c. Phagocytizing bacteria and other foreign particles

d. Make up the majority of the epithelial wall of the alveoli

e. Lining the pleural space

Which of the following statements regarding pulmonary surfactant is TRUE?

a. It is secreted by type I alveolar cells.

b. It increases the compliance of the lungs.

c. It increases airway resistance.

d. It is secreted into the intrapleural space.

e. It can only interact with other lipid molecules.

In which form is most of the oxygen carried in arterial blood?

a. Bound to hemoglobin

b. Dissolved in the plasma

c. Dissolved in the cytosol of erythrocytes

d. Converted to HCO₃ ^-

e. Bound to myoglobin

Which of the following would cause a decrease in the binding affinity of hemoglobin for oxygen?

a. Increased pH of the blood

b. Increased temperature of the blood

c. Decreased DPG levels in erythrocytes

d. The presence of carbon monoxide

e. Decreased concentration of H⁺ in the blood

Carbonic anhydrase catalyzes a reaction that combines which of the following?

a. H₂O and O₂

b. H₂O and CO₂

c. H₂O and CO

d. H⁺ and HCO₃ ^-

e. CO₂ and O₂

After CO₂ is produced by tissues, in what form is most of that carbon transported to the lungs for removal from the body?

a. As dissolved CO₂

b. Bound to hemoglobin

c. As H₂CO₃

d. As dissolved HCO₃ ^-

^{e. As carbonic anhydrase}

Which of these correctly describes the chloride shift?

a. In the lungs, chloride enters red blood cells in exchange for bicarbonate ions.

b. In the tissues, chloride exits red blood cells in exchange for carbonic acid.

c. In the tissues, chloride enters red blood cells in exchange for bicarbonate ions.

d. In the lungs, chloride enters red blood cells in exchange for CO₂.

e. In the tissues, chloride enters red blood cells in exchange for CO₂.

Action potentials in neurons in the inspiratory center of the medulla oblongata result in action potentials in the __________ nerves to the diaphragm, which in turn cause __________ of the muscle, resulting in a/an __________ in the volume of the thoracic cage.

a. motor; contraction; decrease

b. parasympathetic; contraction; decrease

c. sympathetic; contraction; increase

d. motor; contraction; increase

e. sympathetic; relaxation; increase

Which of the following are chemoreceptors?

a. Hair cells in the cochlea

b. Receptors in the aortic and carotid bodies

c. Baroreceptors in the aortic and carotid arch

d. Receptors that mediate the Hering-Breuer reflex

Which of the following statements regarding control of respiration is correct?

a. A slight decrease in arterial P_O2 is a stronger stimulus for increased ventilation than is a comparable decrease in arterial P_CO2.

b. The most important signal for regulating ventilation is the H⁺ concentration of arterial blood.

c. Increased concentrations of lactic acid stimulate ventilation primarily by acting on peripheral chemoreceptors.

d. An increase in the HCO₃ ^- concentration in blood stimulates ventilation.

e. At high altitude, a decrease in P_CO2 of the blood stimulates an increase in ventilation.

Following strenuous exercise, blood levels of lactic acid are __________ compared to pre-exercise levels. This change in acid concentration causes a reflex __________ in ventilation by activating __________.

a. decreased; decrease; peripheral chemoreceptors

b. decreased; decrease; central chemoreceptors

c. increased; increase; baroreceptors in the aortic arch

d. increased; increase; central chemoreceptors

e. increased; increase; peripheral chemoreceptors

Which is characteristic of a person chronically suffering from hypoxic hypoxia?

a. Higher than normal alveolar P_O2

b. Higher-than-normal hematocrit

c. Higher-than-normal arterial P_O2

d. Lower-than-normal lactic acid production

e. Lower-than-normal blood flow through tissues

Which correctly describes the cause of the increase in alveolar ventilation that occurs when a person ascends to high altitude?

a. The decrease in P_CO2 of inspired air decreases alveolar P_CO2, stimulating the peripheral chemoreceptors.

b. The decrease in P_CO2 of inspired air decreases alveolar P_CO2, stimulating the central chemoreceptors.

c. The decrease in P_O2 of inspired air decreases alveolar and arterial P_O2, stimulating the peripheral chemoreceptors.

d. The decrease in total atmospheric pressure causes a greater negative pressure in the intrapleural space, resulting in deeper and more frequent breathing.

e. The decrease in the total barometric pressure at high altitude causes hypocapnea, which stimulates peripheral chemoreceptors.

Under what condition is lung compliance increased?

a. Respiratory distress syndrome of the newborn

b. Prolonged shallow breathing

c. Cystic fibrosis

d. Emphysema

e. Asthma

Which of the following is a cause of asthma?

a. Loss of alveoli

b. Inflammation of the bronchioles

c. Elevation of intrapleural pressure to equal atmospheric pressure

d. Environmental chemicals that stimulate β₂-adrenergic receptors

e. Lack of pulmonary surfactant

Which of the following drugs, administered as an aerosol spray, would be most likely to help a patient during an asthmatic attack?

a. Pulmonary surfactant

b. A β₂-adrenergic agonist

c. A muscarinic agonist

d. Histamine

e. A β₂-adrenergic antagonist

Regarding the relationships between the rates of oxygen consumption/carbon dioxide production and alveolar ventilation, which of these statements is TRUE?

a. Increased ventilation without a similar increase in metabolism is called hypoventilation.

b. In hypoventilation, alveolar P_CO2 decreases below resting levels.

c. In hyperventilation, alveolar P_CO2 can decrease to zero.

d. A decrease in metabolism without a similar decrease in alveolar ventilation would result in hyperventilation.

e. An increase in ventilation with a matching increase in metabolism is called hyperventilation.

Which of these is demonstrated by the oxygen-hemoglobin dissociation curve?

a. The greater the P_O2 of the blood, the greater the dissociation of O₂ from hemoglobin.

b. At normal resting systemic arterial P_O2, hemoglobin is almost 100% saturated with oxygen.

c. At normal resting systemic venous P_O2, only about 75% of the hemoglobin is in the form of deoxyhemoglobin.

d. More additional oxygen binds to hemoglobin when going from a P_O2 of 60 to 100 mmHg, than is added when going from a P_O2 of 40 to 60 mmHg.

e. As P_O2 increases, the saturation of hemoglobin with oxygen increases linearly.

What is the primary regulator of the magnitude of alveolar ventilation under normal circumstances?

a. The H⁺ concentration in the brain extracellular fluid, which is monitored by central chemoreceptors

b. The PO₂ of the arterial blood, which is monitored by central chemoreceptors

c. The PO₂ of the arterial blood, which is monitored by peripheral chemoreceptors

d. The H⁺ concentration in the arterial blood, which is monitored by central chemoreceptors

e. Stretch receptors in the lung

Which of these would tend to increase ventilation?

a. Lower than normal arterial P_CO2

b. Higher than normal arterial pH

c. Breathing carbon monoxide

d. Breathing air with increased P_CO2

e. Iron-deficiency anemia

If the nerves from the carotid and aortic bodies are cut, which of these would occur?

a. A decrease in arterial P_O2 will no longer increase ventilation.

b. An increase in arterial P_CO2 will no longer increase ventilation.

c. An increase in arterial lactic acid will inhibit ventilation.

d. An increase in arterial P_CO2 will inhibit ventilation.

e. A decrease in arterial P_O2 will inhibit ventilation.

Which of the following conditions would result in a systemic arterial P_O2 lower than is typical of a healthy person at sea level?

a. Traveling to high altitude

b. Breathing 100% oxygen

c. Having iron-deficiency anemia

d. Breathing regular air in a hyperbaric chamber (higher that normal atmospheric pressure)

e. Maintaining alveolar ventilation constant while decreasing metabolic rate

Type II alveolar cells are among the last cells to mature during fetal development. In babies born prematurely, type II alveolar cells are often not ready to perform their function. Which of the following would be TRUE of these babies?

a. They would be at risk of alveolar collapse due to too much surface tension in the alveoli.

b. They would be at risk of bacterial infections in the lungs.

c. They would be at risk of autoimmune diseases with lung complications.

d. They would be more likely to have coughing fits.

e. None of these would occur.

During a yoga class you take a deep breath, then relax and let the breath out slowly. During that exhalation, which would NOT be true?

a. Alveolar pressure is greater than atmospheric pressure.

b. Intrapleural pressure is greater than alveolar pressure.

c. Intrapleural pressure becomes less negative.

d. The diaphragm relaxes.

e. Lung volume decreases.

Type II alveolar cells are among the last cells to mature during fetal development. In babies born prematurely, type II alveolar cells are often not ready to perform their functions. Which of the following drugs would be most likely to help an infant with immature type II alveolar cells?

a. Pulmonary surfactant

b. A beta-adrenergic agonist

c. A muscarinic agonist

d. Histamine

e. A beta-adrenergic antagonist

You embark on a hiking trip on Mt. Kilimanjaro (altitude = 19,000 ft; Atmospheric air pressure = 379 mmHg).mHg). As you ascend, what are you likely to notice about your breathing?

a. You need to work to exhale, using your muscles to decrease your thoracic size beyond what is normal

b. You need to work harder to inhale, expanding your thoracic size beyond what is normal

c. Both would happen

d. Neither would happen

During a run, your gastrocnemius (calf) muscle has a temperature of 38.5° C, while your biceps brachii (upper arm) muscle has a temperature of 37.5° C. Which of the following is TRUE of the red blood cells as they pass by these muscles?

a. The hemoglobin molecules will have the same affinity for oxygen at both locations.

b. The hemoglobin molecules will have a higher affinity for oxygen as they pass by the biceps brachii compared to the gastrocnemius.

c. The hemoglobin molecules will have a higher affinity for oxygen as they pass by the gastrocnemius compared to the biceps brachii.

d. The hemoglobin molecules may denature as they pass by the gastrocnemius.

Drug X is a new drug to treat Alzheimer’s Disease. This drug is able to cross the blood-brain barrier and circulate in the CSF. The drug is slightly acidic and at the recommended dose it decreases the CSF pH from 7.4 to 7.3. Will Drug X have any effect on respiration?

a. It will cause an increase in respiratory rate.

b. It will cause a decrease in respiratory rate.

c. It will have no effect on respiratory rate, but will cause an increase in depth of breathing.

d. It will have no effect on respiratory rate, but will cause the patient to take shallower breaths.

e. It will not impact respiratory function.

A decrease in metabolism without a similar, compensatory decrease in alveolar ventilation will have what effect on the systemic pH?

a. pH will decrease.

b. pH will increase.

c. No change to pH is expected in this circumstance.

d. It is impossible to predict the effect on pH without first understanding why metabolism decreased.