Chapter 38
At any given point along the length of the gill lamella, how does the pO_2 of the blood flowing through the blood vessels in the lamella compare to the pO_2 of the water flowing over the gill lamella?
The pO_2 of the blood is lower than the pO_2 of the water.
Which answer option best reflects the difference in oxygen binding by fetal hemoglobin versus maternal hemoglobin?
There is a binding affinity difference such that fetal hemoglobin can remove oxygen from maternal hemoglobin.
Imagine a condition where the vessels that carry blood between the lungs and the body tissues were permeable to oxygen. What would you expect to observe relative to the normal condition of low permeability to oxygen in the vessels that carry blood from the lungs to the tissues?
Rates of diffusion of oxygen at the tissues would decrease because the difference in the concentration of oxygen between blood and tissues would be lower.
If an individual were to absorb a greater volume of fluid from the kidneys, this would increase blood volume. Which of the following would you also expect?
Stroke volume would increase
Certain injuries can cause a decrease in blood pressure. In order for blood flow to remain constant to its value before the injury, resistance would have to increase.
False
At elevations of 10,000 feet, the atmospheric pressure is 522 mmHg. This means that the percentage of oxygen in the air is _____ it is at 760 mmHg.
The same as
Some individuals with lung disease have damage that has resulted in a decrease in the overall amount of surface area in the lungs. What would you expect to see regarding diffusion of oxygen across the lung surface?
Diffusion rates are slower, and less oxygen will be absorbed than in individuals without lung disease.
A researcher has introduced molecules of human myoglobin and hemoglobin into a solution containing oxygen. Which of the statements is true of human hemoglobin and myoglobin?
Compared to human hemoglobin, human myoglobin will likely bind to oxygen molecules more quickly when introduced into the oxygen-containing solution.
When the ventricles are contracting, the SA node will be:
At resting potential
The pacemaker of the mammalian heart is:
A group of specialized cardiac muscle cells that initiate the heartbeat.
Some individuals have varicose veins, veins that are visible due to the pooling of blood in the vessels. Which anatomical condition most likely gives rise to the pooling of blood in veins?
Valves that are unable to open with muscular contraction
What is the main benefit of having hemoglobin in the blood?
It increases the amount of oxygen that can be carried in the blood.
Which of the statements about insect respiration is true?
The insect respiratory system is composed of a series of branching tubes called tracheae.
The heartbeat originates in the:
Sinoatrial node located at the junction of the vena cava and the right atrium.
How is a fetus able to extract O_2 from its mother’s blood?
Fetal hemoglobin has a higher affinity for O_2 than maternal hemoglobin.
An individual with a lung disorder has difficulty expanding their lungs to greater than 50% the volume of an individual without the lung disorder. This would result in _____ tidal volume, _____ air flow, and _____ rates of diffusion of oxygen into the blood.
Decreased; decreased; decreased
Which of the statements is accurate?
Blood flowing to the body tissues of fishes is at a lower pressure than the blood entering the gills.
What percentage of oxygen in the air is typically extracted by the mammalian lung when an animal is resting?
Less than 25%
Ventilation only refers to the movement of oxygen into and out of air sacs or lungs. As a result, fish and other gilled animals do not experience ventilation.
False
A researcher is culturing cells that require oxygen to live in an incubator where the gas levels are carefully regulated. If the researcher observes that the pO_2 in the incubator is 200 mmHg, what can the researcher deduce about the pO_2 of the cells?
The pO_2 of the cells is less than or equal to 200 mmHg.
As you read this sentence, you have breathed in and out. What you have just experienced is referred to as “gas exchange,” where you have taken oxygen into your lungs and expelled carbon dioxide into the environment.
True
What is the function of surfactant in the mammalian respiratory system?
Reduction of surface tension in the fluid covering the alveoli
Inhalation in insects occurs through spiracles along the side of the body. As a researcher, you are curious to know if spiracle activity, being either open or closed, is affected by flight. Your hypothesis is that spiracles will always be open during flight to meet the oxygen demands of muscles used in flight. Which observation would cause you to reject your hypothesis?
You observe the spiracles of the flying insect opening for two hours and then closing for two hours throughout the day.
