Chapter 42 Bio 102

Chambers A and B are separated by a membrane permeable to substance X. The concentration of X is 5% in A and 15% in B. The volume of A is three times that of B. Which of the following will occur?

Although diffusion is random, the result will be the net movement of X from B to A.

_____ in carbon dioxide in your red blood cells, which causes _____ in pH, causes your breathing to speed up.

An increase ... a drop

Why does the velocity of blood slow greatly as blood flows from arterioles into capillaries?

Because capillary beds have a total cross-sectional area much greater than the total cross-sectional area of the arterioles.

Select the correct statement about capillary beds.

Capillary beds are the site of nutrient and oxygen delivery to tissues.

Based on the graph, which of the following statements is correct?

Hemoglobin has a lower affinity for oxygen under high temperature conditions.

Which statement about lipoproteins is correct?

High-density lipoproteins are cholesterol transporters in the blood.

What is the function of a circulatory system?

It brings a transport liquid into close contact with all cells in the body.

Which statement about human blood vessels is correct?

Pulmonary veins carry oxygen-rich blood to the heart.

Hyperventilation (rapid inhalation and exhalation) can result in respiratory alkalosis (increased blood pH). Why?

Rapid breathing depletes the blood of carbon dioxide, thus the blood pH increases.

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?

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

Which event of the cardiac cycle occurs when systolic blood pressure is measured?

The ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria.

Humans infected with some types of parasitic worms develop a condition called elephantiasis, which is characterized by swelling of the limbs. Which of the following would be the most likely cause of elephantiasis?

The worms are blocking the lymph vessels.

While jogging, a person has a stroke volume of 130 ml/beat and a heart rate of 120 beats per minute. If their resting stroke volume was 70 ml/beat and resting heart rate was 60 beats per minute, how did this person's cardiac output change?

Their cardiac output increased from 4,200 ml/minute to 15,600 ml/minute after jogging.

Which of the following statements about blood circulation in the body is true?

Valves prevent the backflow of blood into the atria and ventricles.

Consider the following reaction. If the pH of the blood was decreased, then the ________. CO2 + H2O ↔ H2CO3 ↔ HCO3- + H+

amount of carbon dioxide would increase

An anthropologist discovers the fossilized heart of an extinct animal. The evidence indicates that the organism's heart was large, was 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

An oil-water mixture works as an insecticidal spray against mosquitoes and other insects because it _____.

blocks the openings into the tracheal system

The diagnosis of hypertension in adults is based on the _____.

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

The smallest airway through which inspired air passes before gas exchange occurs in the mammalian lungs is the _____.

bronchiole

Compared to mammals that are not adapted for diving, diving mammals ________.

can store more oxygen in their muscles

During most daily activities, the human respiration rate is most closely linked to the blood levels of _____.

carbon dioxide

Most of the carbon dioxide produced by humans is ________.

converted to bicarbonate ions

To become bound to hemoglobin for transport in mammals, atmospheric molecules of oxygen must cross ________.

five membranesin and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary, and into the red blood cellto bind with hemoglobin

If the osmotic pressure on the venous side of capillary beds is lower than the hydrostatic pressure, then ________.

fluid will tend to accumulate in tissues

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

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

Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arteries has a

higher P(O2).

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

increased activity of the immune system

Which of the following represents the correct flow of air into the lung of a mammal?

larnyx → trachea → bronchi → bronchioles → alveoli

Voice sounds are produced by the _____.

larynx

Blood returning to the mammalian heart in a pulmonary vein drains first into the

left atrium

The primary functions of the _____ are to warm, filter, and humidify air.

naval cavity

In an open circulatory system, blood is _____.

not always confined to blood vessels and is under lower pressure than in closed circulatory systems

Cellular respiration

produces CO2 and ATP.

Blood returns to the heart via the _____.

pulmonary veins

From the superior vena cava, blood flows to the _____.

right atrium

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

systole of the left ventricle

Carbon dioxide levels in the blood and cerebrospinal fluid affect pH. This enables the organism to sense a disturbance in gas levels as _____.

the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing

One feature that amphibians and humans have in common is

the number of circuits for circulation.

The greatest difference in the concentration of respiratory gases is found in which of the following pairs of mammalian blood vessels?

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

the pulmonary vein.

An electrocardiogram (ECG) provides information about ________.

the rhythm of heart contractions

A person with a tidal volume of 450 mL (milliliters), a vital capacity of 4000 mL, and a residual volume of 1000 mL would have a potential total lung capacity of _____.

5000 mL

Which of the following best describes an artery?

Arteries carry blood away from the heart.

In order for blood to always flow unidirectionally through a closed circulatory system, the ________.

blood vessels farthest from the heart must have valves

Which of the following conditions would most likely be due to high blood pressure in a mammal?

bursting of blood vessels in capillary beds

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

giraffe

What would be the consequence if we were to reverse the direction of water flow over the gills of a fish, moving water inward past the operculum, past the gills, then out the mouth? This reversal of water flow would ________.

reduce efficiency of gas exchange

When you hold your breath, which of the following blood gas changes first leads to the urge to breathe?

rising CO2

A patient with a heart rate of 70 beats per minute and a stroke volume of 70 mL/beat will have a cardiac output of ________.

4,900 mL/minute

When the air in a testing chamber is specially mixed so that its oxygen content is 10% and its overall air pressure is 400 mm Hg, then PO2 is ________.

40 mm Hg

The amount of oxygen bound to hemoglobin _____.

increases in the presence of high concentrations of oxygen

Atmospheric pressure at the summit of Mount Everest is about one third the pressure at sea level, which is 760 mm Hg. If oxygen makes up 21% of the atmosphere by volume, the partial pressure of oxygen (PO2) on Mount Everest is approximately ________.

53 mm Hg

________ is a hormone that is released from the ________ to stimulate the production of red blood cells.

Erythropoietin; kidney

How has the avian lung adapted to the metabolic demands of flight?

Gas exchange occurs during both inhalation and exhalation.

Which of the following mechanisms are used to regulate blood pressure in the closed circulatory system of vertebrates? I) changing the force of heart contraction II) constricting and relaxing smooth muscle in the walls of arterioles III) opening or closing precapillary sphincters

I, II, and III

Which statement regarding the mammalian heart is correct?

In the adult heart, blood in the right chambers of the heart cannot enter the left chambers without passing through the lungs.

How are gases transported in insect bodies?

In tracheal systems

What is the function of the left ventricle?

It pumps oxygenated blood around the body via the systemic circulation.

Which of the following events would you predict as carbon dioxide is released from your muscles into the surrounding capillary bed?

Oxygen delivery to muscle is increased when more carbon dioxide is produced by the muscle.

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?

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

Which of the following would you expect of a species that has a high resting cardiac output?

The animal likely has a very long distance between its heart and its brain.

Which event occurs first during atrial and ventricular diastole?

The atria and ventricles are relaxed, and blood flows into the atria.

Why do the circulatory systems of land vertebrates have separate circuits to the lungs and to the rest of the body?

The large decrease in blood pressure as blood moves through the lungs may prevent efficient circulation through the rest of the body.

Which of the following statements comparing respiration in fish and in mammals is correct?

The movement of the respiratory medium in mammals is bidirectional, but in fish it is unidirectional.

A rabbit taken from a meadow near sea level and moved to a meadow high on a mountainside would have some trouble breathing. Why?

The partial pressure of oxygen in the air at high elevations is lower than at sea level.

Select the correct statement about the three-chambered hearts of amphibians and nonbird reptiles.

The three-chambered hearts of amphibians and nonbird reptiles are facultative, allowing variation in blood flow through the heart.

Although having evolved independently, the tracheal tubes of mammals and insects are both supported by rigid tissues. The trachea of a mammal is supported by cartilage, and the tracheae of an insect are supported by chitin. What selective pressure most likely led to the convergent evolution of these respiratory structures?

When air is the respiratory medium, there is a greater risk that the tracheal tubes will collapse.

Stroke occurs when _____.

a blood clot enters the cerebral circulation, blocking an artery and causing the death of brain tissue

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

A normal event in the process of blood clotting is the _____.

activation of prothrombin to thrombin

Cyanide poisons mitochondria by blocking the final step in the electron transport chain. Human red blood cells placed in an isotonic solution containing cyanide are likely to _____.

be unaffected

During aerobic exercise, the partial pressure of oxygen in muscle cells will ________, thus the rate of diffusion of oxygen into the muscle tissue from the blood will ________.

decrease; increase

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

development of an osmotic pressure difference across capillary walls

Countercurrent exchange in the fish gill helps to maximize _____.

diffusion

Damage to the sinoatrial node in humans would ________.

disrupt the rate and timing of cardiac muscle contractions

Which of the following organisms has no specialized respiratory structures?

earthworms

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

fishes

A decrease of blood pH from 7.4 to 7.2 causes hemoglobin to ________.

give up more of its oxygen molecules

In which of the following animals are the blood and the interstitial fluid considered to be the same body fluid?

grasshoppers

Under identical atmospheric conditions, freshwater ________.

has more dissolved oxygen than seawater

Pulse is a direct measure of

heart rate

From the capillaries of the abdominal organs and hind limbs, blood flows to the _____.

inferior vena cava

From the pulmonary veins, blood flows to the _____.

left atrium

Blood cells that function to fight infection are called ________.

leukocytes

Some human infants, especially those born prematurely, suffer serious respiratory failure because of _____.

lung collapse due to inadequate production of surfactant

Atrial systole ________.

occurs at the same time as ventricular diastole

As a property of enzymes, cooperativity refers to

one enzyme subunit altering the behavior of others.

The sun shining on a tidal pool during a hot day heats the water, causing some water to evaporate. Because the water has become warmer and saltier, ________.

the oxygen content will decrease

The circulatory systems of bony fishes, rays, and sharks are most similar to _____.

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

Circulatory systems compensate for _____.

the slow rate at which diffusion occurs over large distances

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

Which of the following respiratory systems is not closely associated with a blood supply?

the tracheal system of an insect

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 to the thumb and then back 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 birds and mammals?

vena cava → right atrium → right ventricle → pulmonary artery

Countercurrent exchange is evident in the flow of _____.

water across the gills of a fish and the blood within those gills

An advantage of gas exchange in fresh water, compared with gas exchange in air, is that _____.

water loss through evaporation across the respiratory surface can be minimized