Chapter 42
At an atmospheric pressure of 870 mm Hg of 21% oxygen, the partial pressure of oxygen is
182 mm Hg
A person with a tidal volume of 450 mL, a vital capacity of 4,000 mL, and a residual volume of 1,000 mL would have a potential total lung capacity of
5,000 mL
Diffusion rate is proportional to the square of the distance of molecules ions traveled. Which of the following would therefore be preferable for a midsized multicellular organism?
A system to circulate gases nutrients and wastes to and from cells
If the atrioventricular node could be surgically removed from the heart without disrupting signal transmission to the Purkinje fibers, what would be the effect?
Atria and ventricles would contract at about the same time.
What would be the long-term effect if the lymphatic vessels associated with a capillary bed were to become blocked?
Fluid would accumulate in interstitial areas.
For this capillary bed, which of the following statements is correct?
Fluids will leave the capillaries on the arterial side amid the bed and re enter on the venous side
How does the hemocyanin of arthropods and molluscs differ from the hemoglobin of mammals?
Hemocyanin has protein coupled to copper rather than iron.
Frogs put in smoke environment..most likely outcome?
Skin cancer
Which of the following is are a cause of vasoconstriction?
Stress or hormone concentration
What would be the expected if the amount of interstitial fluid surrounding the capillary beds of the lungs were to increase significantly?
The amount of oxygen entering the circulation from the lungs would decrease.
A species has a normal resting systolic blood pressure of >260 mm Hg. What is the most probable hypothesis?
The animal has a very long distance between heart and brain.
Cyanide acts as a mitochondrial poison by blocking the final step in the electron transport chain. What will happen to human red blood cells if they are placed in an isotonic solution containing cyanide?
The cells will probably be unaffected.
What is the reason that fluid is forced from the bloodstream to the surrounding tissues at the arteriole end of systemic capillaries?
The hydrostatic pressure of the blood is greater than the osmotic pressure of the blood.
Birds have negative pressure breathing, but it differs from that of mammals and is more efficient because of which of the following reasons?
The maximum PO2 is significantly higher in bird lungs.
Blood carbon dioxide levels determine the ph of other body fluids as well as blood, including the ph of cerebrospinal fluid. How does this enable the organism to control breathing?
The medulla, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing.
An oil-water mixture is used as a spray against mosquitoes. How might this spray also affect gas exchange in other insects?
The oil might block the openings into the tracheal system.
Why is the velocity of blood flow the lowest in capillaries?
The total surface area of the capillaries is larger than the total surface area of the arterioles.
Which of the following occurs with the exhalation of air from human lungs?
The volume of the thoracic cavity decreases.
Which of the following lung volumes would be different in a person at rest compared with when the person exercises?
Tidal volume
Why is gas exchange more difficult for aquatic animals with gills than for terrestrial animals with lungs?
Water contains much less O2 than air per unit volume.
In an animal species known for endurance running rather than fast sprinting, you would expect to find
a much higher rate of oxygen consumption for its size
Which of the following is a normal event in the process of blood clotting?
activation of prothrombin to thrombin
A blood vessel has the following characteristics: outer layer of connective tissue, a thick layer of smooth muscle with elastic fibers, no valves. It is which of the following?
an artery
Emphysema is a disease, frequently caused by smoking, that results in loss of the elastic elements of lung tissue. The effect will be more like which of the following?
an increase in airway resistance
How is most of the carbon dioxide transported by the blood in humans?
bicarbonate ions in the plasma
Organisms in which a circulating body fluid is distinct from the fluid that directly surrounds the body's cells are likely to have
closed circulatory system
In negative pressure breathing inhalation results from
contracting the diaphragm
The meshwork that forms the fabric of a blood clot is
fibrin
Human plasma proteins include which of the following?
fibrinogen and immunoglobulin
Which of the following are the only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart?
fishes
If, during protein starvation, the osmotic pressure on the venous side of capillary beds drops below the hydrostatic pressure, then
fluids will tend to accumulate in tissues.
A nonfunctional sinoatrial node would
have little significant effect on stroke volume.
Pulse is a direct measure of
heart rate
Hydrogen ions produced within human red blood cells are prevented from significantly lowering plasma pH because they bind to
hemoglobin
Which of the following is predicted in someone who smokes and whose diet includes significant trans fats
increased blood vessel inflammation
Blood returning to the heart from the pulmonary circuit first enters the
left atrium
Which of these are involved in the early stages of blood clotting?
platelets
Tidal volume in respiration is analogous to what measurement in cardiac physiology?
stroke volume
An anthropologist discovers fossilized animal remains that give strong evidence that the organism had a large, well-formed, most likely 4-chambered heart, with no connection between the right and left sides. Which of the following could most reasonably be hypothesized from this observation?
that the animal had a high energy requirement and was endothermic
Which of the following is measured by an electrocardiogram?
the spread of impulses from the SA node
Which of the following respiratory systems is not closely associated with a blood supply?
the tracheal system of an insect
Which of the following is a characteristic of both hemoglobin and hemocyanin?
transports oxygen
A human red blood cell in an artery of the left arm is on its way to deliver oxygen to a cell in the thumb. From this point in the artery, how many capillary beds must this red blood cell pass through before it returns to the left ventricle of the heart?
two
Average blood pressure is lowest in which structure(s)?
venae cavae
Damage to the sinoatrial node in humans
would disrupt the rate and timing of cardiac muscle contractions
