Exam 18: Gas Exchange and Transport

Blocking afferent action potentials from the chemoreceptors in the carotid and aortic bodies would interfere with the brain's ability to regulate breathing in response to all EXCEPT which of the following?

Of the factors that influence diffusion of respiratory gases, the most variable and, therefore, important factor to consider is the

In the science fiction movie The Abyss, a diver is able to breathe while his head is immersed in a specially prepared liquid pumped into a water-tight helmet attached to a suit, thus allowing him to dive without an air tank and at greater depths than possible for scuba divers.Is this purely fiction, or is it at least theoretically possible? Explain, considering the nature of alveoli and alveolar gas exchange.Assuming it is possible, describe the composition and nature of the liquid in terms of its oxygen pressure and concentration.

Diffusion rate is directly proportional to ________ and ________.

At a PO₂ of 70 mm Hg and normal temperature and pH, hemoglobin is ________% saturated with oxygen.

________ is characterized by a decreased surface area for gas exchange in the lungs.

Diffusion rate is indirectly proportional to ________.

What are the two possible causes of lower alveolar PO₂? Give examples of each.

Hemoglobin binds to and has a much higher affinity for carbon monoxide (CO)than for oxygen.CO is colorless and odorless and can be produced in homes heated by natural gas; victims usually do not realize they are being poisoned and often die in their sleep.Describe the likely changes in a CO poisoning victim.

In the medulla oblongata, the nucleus tractus solitarius contains the ________ of neurons.

Explain how oxygen and carbon dioxide are transported in the blood.How does the means of transport relate to the solubility and chemical reactivity of these gases in plasma?

Match the lung disease to its description. -thickened alveolar membrane and decreased lung compliance

Specialized ________ in the carotid and aortic bodies are activated by a decrease in PO₂ and pH or an increase in PCO₂.What do they trigger?

Jill lives in St.Louis, which is close to sea level.She decides to spend a month of her summer vacation working in the mountains outside of Denver.After a week in the mountains, what kinds of changes would you expect to see as Jill adapts to the higher altitude?

Match the lung disease to its description. -destruction of alveoli

Match the factor with its effect on the affinity of hemoglobin for oxygen. -increased PCO₂

The graph below shows an oxygen dissociation curve, with the normal curve in the center.What is the name of the phenomenon that shifts the curve to the right? What causes this change in oxygen dissociation? Is the shift beneficial or detrimental? Explain.

Match the lung disease to its description. -increased airway resistance

Inappropriate relaxation of the ________ muscles during sleep contributes to ________, a sleep disorder associated with snoring.

Write the chemical equation catalyzed by the enzyme carbonic anhydrase.Suppose the concentration of H⁺ is increased by an outside force in a solution that had been at equilibrium.According to the law of mass action, what must happen to the CO₂ concentration to reestablish equilibrium after this disturbance? What must happen to the concentration of bicarbonate?