A paleontologist 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

animal was endothermic and had a high metabolic rate

A group of students was designing an experiment to test the effect of smoking on grass frogs. They hypothesized that keeping the frogs in a smoke-filled environment for defined periods would result in the animals developing lung cancer. However, when they searched for previously published information to shore up their hypothesis, they discovered they were quite wrong in their original assessment. Even though they were never going to go ahead with their experiment (so as not to harm frogs needlessly), they knew that a more likely outcome of putting carcinogens in the air would be the development of

skin cancer

Gas exchange in the aquatic salamander known as the axolotl is correctly described as

simple diffusion of oxygen into the salamander from the water

Circulatory systems compensate for

the slow rate at which diffusion occurs over large distances.

The fluid that moves around in the circulatory system of a typical arthropod is

the interstitial fliud

The circulatory system of bony fishes, rays, and sharks is similar to

the portal systems of mammals, where two capillary beds occur sequentially, without passage of blood through a pumping chamber

Organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body's cells are likely to have

a closed circulatory system

In which of the following organisms does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body?

frogs

The only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart are the

fishes

To adjust blood pressure independently in the capillaries of the gas-exchange surface and in the capillaries of the general body circulation, an organism would need a(n)

four-chambered heart

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. To travel from the artery in the arm to the left ventricle, this red blood cell must pass through

two capillary beds

Which of the following is the correct sequence of blood flow in reptiles and mammals?

vena cava → right atrium → right ventricle → pulmonary circuit

A patient with a blood pressure of 120/75, a pulse rate of 40 beats/minute, a stroke volume of 70 mL/beat, and a respiratory rate of 25 breaths/minute will have a cardiac output of

2,800 mL/minute

Damage to the sinoatrial node in humans

would disrupt the rate and timing of cardiac muscle contractions

A stroke volume in the heart of 70 mL/cycle, with a pulse of 72 cycles per minute, results in a cardiac output of

5 L/minute

The semilunar valves of the mammalian heart

prevent backflow of blood in the aorta and pulmonary arteries

Heart rate will increase in the presence of increased

epinephrine

Which of the following develops the greatest pressure on the blood in the mammalian aorta?

systole of the left ventricle

The material present in arterioles that is not present in capillaries is

circular smooth muscle cells that can alter the size of the arterioles

The set of blood vessels with the slowest velocity of blood flow is

the capillaries

The set of blood vessels with the lowest blood pressure driving flow is

the veins

An increased concentration of nitric oxide within a vascular bed is associated with

vasodilation

Among the following choices, which organism likely has the highest systolic pressure?

giraffe

Small swollen areas in the neck, groin, and axillary region are associated with

increased activity of the immune system

The velocity of blood flow is the lowest in capillaries because

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

The blood pressure is lowest in the

vena cava

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.

What will be the long-term effect of blocking the lymphatic vessels associated with a capillary bed?

the accumulation of more fluid in the interstitial areas

A species that has a normal resting systolic blood pressure of >260 mm Hg is likely to be

an animal that has a very long distance between its heart and its brain.

Large proteins such as albumin remain in capillaries rather than diffusing out, resulting in the

development of an osmotic pressure difference across capillary walls.

Large proteins such as albumin remain in capillaries rather than diffusing out, resulting in the

development of an osmotic pressure difference across capillary walls

The diagnosis of hypertension in adults is based on the

blood pressure being greater than 140 mm Hg systolic and/or >90 diastolic

Dialysis is the process of filtering the blood; it is performed when kidney functionality is below normal. During dialysis, plasma and its proteins are separated from the cells. Dialysis patients, who will have blood withdrawn, dialyzed, and then replaced, are always weighed when they enter the facility and then weighed carefully again before they leave, because

even small changes in body weight may signify changes in blood volume and therefore blood pressure.

Vasoconstriction of blood vessels delivering blood to the gut is a likely response when an individual is

stressed and secreting stress hormones

In a healthy human, the typical life span of a red blood cell is

4 months

The hormone that stimulates the production of red blood cells and the organ where this hormone is synthesized are

erythropoietin and kidney, respectively