Exam 22: Gas Exchange

Which of the figures shown represents countercurrent exchange? The arrows indicate direction of flow, and the numbers indicate concentration of a gas.

Formaldehyde is a simple organic molecule with important industrial uses; however it is a known carcinogen (cancer-causing compound). Researchers have long known that formaldehyde is present in cigarette smoke, but it was only recently in 2014 that researchers determined that formaldehyde is also present in e-cigarette vapor. For this and other reasons, the U.S. FDA is now overseeing production and distribution of e-cigarettes. The data below are compiled from several studies examining the levels of formaldehyde in cigarette smoke and low- and high-voltage e-cigarette vapor (increasing the voltage of an e-cigarette allows for increased nicotine intake). The data in bar A are from individuals consuming 20 cigarettes a day. The data in bar B are from individuals consuming 3 mL of e-cigarette fluid a day when the e-cigarette is set to low voltage (n.d. = not detectable). The data in bar C are from individuals consuming 3 mL of e-cigarette fluid a day when the e-cigarette is set to high voltage. -Assuming e-cigarettes contain many similar chemical compounds to traditional cigarettes, what part of the respiratory system do they likely negatively affect?

When you hyperventilate (breathe too fast), respiratory alkalosis (decreased concentration of hydrogen ions in the blood) can occur, which can cause you to faint. A common but potentially dangerous method to reverse respiratory alkalosis is to hold a paper bag over your mouth and take normal breaths, thereby rebreathing the exhaled air. How might this method reverse respiratory alkalosis?

Physicians routinely give their patients pulmonary function tests in order to measure characteristics of lung function. The most common of these tests, spirometry, measures both the volume and the speed of air entering and exiting the lungs. In this test, a person first breathes normally while breathing into a spirometer, a machine that measures air volume and air speed. Then the person takes the deepest breath possible and exhales as hard as possible for 6 seconds into the spirometer. The resulting data are plotted on a graph of volume (y axis) versus time (x axis). Spirometry is useful not only for assessing lung function in healthy patients but also for characterizing patients with lung conditions such as pulmonary fibrosis, asthma, or emphysema. A sample graph for a healthy adult male is shown below. Normal breathing occurs between points A and B, a maximal inhalation occurs at point C, and a maximal exhalation occurs at point D. Normal breathing resumes between points E and F. -For this data set, what is the residual volume of the lungs?

What part of the human brain contains control centers that establish a breathing rhythm?

Sometime after a human baby is born, the production of the fetal hemoglobin protein ceases and the production of the adult hemoglobin protein begins. Imagine that a baby is born and this switch from fetal to adult hemoglobin does not occur. In which part of the world would this baby be well adapted to living?

Which of the following organisms has a respiratory system that does not require assistance from a circulatory system for gas exchange?

Which of the following statements regarding breathing and circulation in insects is false?

There is a condition that affects the lungs such that the lungs cannot remove all of the CO₂ that the body produces. Fortunately, animals' bodies respond to rising CO₂ levels, which can prevent this condition from occurring. Which of the following processes occur when CO₂ rises?

Labored breathing, coughing, lung infections, and respiratory failure are characteristics defining

Cigarette smoking can sometimes lead to development of a "smoker's cough," which results from paralysis of cilia in the airways. Why would the paralysis of cilia lead to smoker's cough?

Oxygen is mostly transported through the body in which of the following forms?

Physicians routinely give their patients pulmonary function tests in order to measure characteristics of lung function. The most common of these tests, spirometry, measures both the volume and the speed of air entering and exiting the lungs. In this test, a person first breathes normally while breathing into a spirometer, a machine that measures air volume and air speed. Then the person takes the deepest breath possible and exhales as hard as possible for 6 seconds into the spirometer. The resulting data are plotted on a graph of volume (y axis) versus time (x axis). Spirometry is useful not only for assessing lung function in healthy patients but also for characterizing patients with lung conditions such as pulmonary fibrosis, asthma, or emphysema. A sample graph for a healthy adult male is shown below. Normal breathing occurs between points A and B, a maximal inhalation occurs at point C, and a maximal exhalation occurs at point D. Normal breathing resumes between points E and F. -How is spirometry a potentially flawed experimental method to measure lung volume?

Consider an animal that exchanges gases through its skin. Which of the following body shapes would provide the most surface area for gas exchange?

Formaldehyde is a simple organic molecule with important industrial uses; however it is a known carcinogen (cancer-causing compound). Researchers have long known that formaldehyde is present in cigarette smoke, but it was only recently in 2014 that researchers determined that formaldehyde is also present in e-cigarette vapor. For this and other reasons, the U.S. FDA is now overseeing production and distribution of e-cigarettes. The data below are compiled from several studies examining the levels of formaldehyde in cigarette smoke and low- and high-voltage e-cigarette vapor (increasing the voltage of an e-cigarette allows for increased nicotine intake). The data in bar A are from individuals consuming 20 cigarettes a day. The data in bar B are from individuals consuming 3 mL of e-cigarette fluid a day when the e-cigarette is set to low voltage (n.d. = not detectable). The data in bar C are from individuals consuming 3 mL of e-cigarette fluid a day when the e-cigarette is set to high voltage. -What can you conclude from these data?

Many amphibians (including many frogs, toads, and salamanders) spend the early part of their lives in water but live on land as adults. The adults of many species return to water to breed and lay their eggs. Frogs have small lungs and supplement their oxygen intake by breathing through the skin. Although large frogs have more total surface area than smaller frogs, the larger frogs have a lower surface area/volume ratio (less skin surface relative to their total body volume). To keep their respiratory surfaces moist, frogs are generally found in wet or very moist locations. In an experiment designed to investigate oxygen consumption in relation to body size, frogs from five different species were weighed and placed in a respirometer (a machine that measures oxygen consumption) for 1 hour. The table shows the results of the experiment. Species Average Weight (grams) Oxygen Consumption in One Hour (cc) A 7 0.35 B 11 0.55 C 15 0.75 D 21 1.05 E 37 1.85 -You have obtained a frog from a species closely related to the frogs used in the preceding study. If the frog weighs 30 grams, what do you expect its oxygen consumption in 1 hour to be?

Cigarette smoking causes cancer due to the

Some crocodiles and turtles have an exceptional ability to divert blood flow through the heart when they are diving and no longer breathing and exchanging gases. Which of the following most likely occurs when these animals dive?

Animals that effectively use their body surface for gas exchange must

If the hemoglobin molecules in your red blood cells suddenly were unable to bind carbon dioxide and hydrogen ions, what would happen to your blood pH?