Mastering Biology Chapter 42 (Cut)

You cut your finger, and after putting pressure on the wound for several minutes, you notice that it is still bleeding profusely. What may be the problem? A) Platelets are not functioning properly, or there are too few to be effective B) Mast cells are not releasing their chemical messengers C) There are too many antigens to allow clotting D) Hemoglobin levels are too high to allow clotting

A) Platelets are not functioning properly, or there are too few to be effective

Countercurrent exchange is evident in A) the flow of water across the gills of a fish and that of blood within those gills. B) the flow of blood in the dorsal vessel of an insect and that of air within its tracheae. C) the flow of air within the primary bronchi of a human and that of blood within the pulmonary veins. D) the flow of water across the skin of a frog and that of blood within the ventricle of its heart. E) the flow of fluid out of the arterial end of a capillary and that of fluid back into the venous end of the same capillary.

A) the flow of water across the gills of a fish and that of blood within those gills.

The greatest difference in the concentration of respiratory gases is found in which of the following pairs of mammalian blood vessels? A. the pulmonary vein and the superior vena cava B. the veins from the right and left legs C. the pulmonary vein and the aorta D. the pulmonary artery and the inferior vena cava

A) the pulmonary vein and the superior vena cava

If a molecule of CO₂ released into the blood in your left toe is exhaled from your nose, it must pass through all of the following except A) the pulmonary vein. B) an alveolus. C) the trachea. D) the right atrium. E) the right ventricle.

A) the pulmonary vein.

Blood is pumped at high pressures in arteries from the heart to ensure that all parts of the body receive adequate blood flow. Capillary beds, however, would hemorrhage under direct arterial pressures. How does the design of the circulatory network contribute to reducing blood pressure to avoid this scenario? A) Blood flow through the capillaries is essentially frictionless, and this reduces the amount of pressure on their walls. B) The total cross-sectional diameter of the arterial circulation increases with progression from artery to arteriole to capillary, leading to a reduced blood pressure. C) Fluid loss from the arteries is high enough that pressure drops off significantly by the time blood reaches the capillaries. D) Capillary beds have the thickest walls of any blood vessel to resist these high pressures.

B) The total cross-sectional diameter of the arterial circulation increases with progression from artery to arteriole to capillary, leading to a reduced blood pressure.

Organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body's cells are likely to have A) an open circulatory system. B) a closed circulatory system. C) a gastrovascular cavity. D) branched tracheae. E) hemolymph.

B) a closed circulatory system.

The sun shining on a tidal pool during a hot day heats the water. As some water evaporates, the pool becomes saltier, causing A) a decrease in its carbon dioxide content. B) a decrease in its oxygen content. C) an increase in its ability to sustain aerobic organisms. D) a decrease in the water's density. E) a decrease in the movement of the water molecules.

B) a decrease in its oxygen content.

An anthropologist discovers the fossilized heart of an extinct animal. The evidence indicates that the organism's heart was large, well-formed, and had four chambers, with no connection between the right and left sides. A reasonable conclusion supported by these observations is that the A) animal had evolved from birds. B) animal was endothermic and had a high metabolic rate. C) animal was most closely related to alligators and crocodiles. D) Animal was likely an invertebrate animal. E) species had little to no need to regulate blood pressure.

B) animal was endothermic and had a high metabolic rate.

An oil-water mixture works as an insecticidal spray against mosquitoes and other insects because it A) coats their lungs. B) blocks the openings into the tracheal system. C) interferes with gas exchange across the capillaries. D) clogs their bronchi. E) prevents gases from leaving the atmosphere.

B) blocks the openings into the tracheal system.

In order for the blood to always flow indirectly through a closed circulatory system, the __________. A) blood vessels farthest from the heart must have valves B) capillaries must have a thick endothelium C) arteries must be elastic D) pressure in all vessels must be equal

B) capillaries must have a thick endothelium

Blood returning to the mammalian heart in a pulmonary vein drains first into the A) vena cava. B) left atrium. C) right atrium. D) left ventricle. E) right ventricle.

B) left atrium.

Circulatory systems compensate for _____. A) temperature differences between the lungs and the active tissue B) the slow rate at which diffusion occurs over large distances C) the problem of communication systems involving only the nervous system D) the need to cushion animals from trauma

B) the slow rate at which diffusion occurs over large distances

The only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart are the A) amphibians. B) birds. C) fishes. D) mammals. E) reptiles.

C) fishes.

When you hold your breath, which of the following blood gas changes first leads to the urge to breathe? A) rising O₂ B) falling O₂ C) rising CO₂ D) falling CO₂ E) rising CO₂ and falling O₂

C) rising CO₂

Which of the following develops the greatest pressure on the blood in the mammalian aorta? A) systole of the left atrium B) diastole of the right ventricle C) systole of the left ventricle D) diastole of the right atrium E) diastole of the left atrium

C) systole of the left ventricle

Which of the following respiratory systems is not closely associated with a blood supply? A) the lungs of a vertebrate B) the gills of a fish C) the tracheal system of an insect D) the skin of an earthworm E) the parapodia of a polychaete worm

C) the tracheal system of an insect

During most daily activities, the human respiration rate is most closely linked to the blood levels of A) nitric acid. B) nitrogen. C) oxygen. D) carbon dioxide. E) carbon monoxide.

D) carbon dioxide.

Pulse is a direct measure of A) blood pressure. B) stroke volume. C) cardiac output. D) heart rate. E) breathing rate.

D) heart rate.

In an open circulatory system, blood is _____. A) always inside of vessels B) not confined in vessels and is under high pressure C) always inside pressure and under low pressure D) not always in vessels and is under low pressure

D) not always in vessels and is under low pressure

Which of the following is the correct sequence of blood flow in birds and mammals? A) left ventricle → aorta → lungs → systemic circulation B) right ventricle → pulmonary vein → pulmocutaneous circulation C) pulmonary vein → left atrium → left ventricle → pulmonary circuit D) vena cava → right atrium → right ventricle → pulmonary artery E) right atrium → pulmonary artery → left atrium → ventricle

D) vena cava → right atrium → right ventricle → pulmonary artery

The velocity of blood flow is the lowest in capillaries because A) the capillary walls are not thin enough to allow oxygen to exchange with the cells. B) the capillaries are far from the heart, and blood flow slows as distance from the heart increases. C) the diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate. D) the systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventricle. E) the total cross-sectional area of the capillaries is greater than the total cross-sectional area of the arteries or any other part of the circulatory system.

E) the total cross-sectional area of the capillaries is greater than the total cross-sectional area of the arteries or any other part of the circulatory system

Describe the one-way countercurrent exchange in the respirartory system of birds

blood flows in the opposite direction of water, flowing over the top of the gills allowing them to remove more than 80% of the dissolved oxygen in the water

Why is the velocity of blood flow the lowest in capillaries?

capillaries are extremely thin, only one cells layer thick

Mammalian lungs evolved from what organism?

fish

What is the benefit of gas exchange in the air compared with gas exchange in water?

water is only 1% oxygen where the air is 28% oxygen