Chapter 42: Circulation and Gas Exchange

Which of the following is an example of a portal vein? A. A blood vessel carrying blood from the major muscles of the lower leg back to the heart B. A blood vessel carrying blood from the heart to the lungs C. A blood vessel carrying blood from the stomach to the liver D. A blood vessel carrying blood from the heart to the muscles of the lower leg E. A blood vessel carrying blood from the lungs to the heart

C. A blood vessel carrying blood from the stomach to the liver

Which of the following best describes an artery? A. Arteries carry blood away from capillaries. B. Arteries contain valves. C. Arteries carry blood away from the heart. D. Arteries carry oxygenated blood. E. Arteries have thin walls compared with veins.

C. Arteries carry blood away from the heart.

Why does the velocity of blood slow greatly as blood flows from arterioles into capillaries? A. Because capillary beds are the site of nutrient and oxygen delivery to tissues. B. Because the narrow capillaries offer great resistance to blood flow. C. Because capillary beds have a total cross-sectional area much greater than the total cross-sectional area of the arterioles.

C. 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. A. Capillary beds have a total cross-sectional area much smaller than the total cross-sectional area of major arteries. B. Capillary beds join arteries and veins. C. Capillary beds are the site of nutrient and oxygen delivery to tissues.

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

What is the function of the left ventricle? A. It receives deoxygenated blood from the lungs. B. It receives oxygenated blood from the lungs. C. It pumps oxygenated blood around the body via the systemic circulation. D. It pumps deoxygenated blood to the lungs via the pulmonary circulation.

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

Which chambers of the heart respectively receive and pump oxygen-poor blood? A. Left atrium and right ventricle B. Right atrium and left ventricle C.Right atrium and right ventricle D. Left atrium and left ventricle

C. RIght atrium and right ventricle

Which of the following correctly lists the sequence of blood flow in mammals? A. Lungs, pulmonary arteries, right ventricle, right atrium, venae cavae, pulmonary veins, left atrium, left ventricle, aorta B. Aorta, left ventricle, left atrium, pulmonary veins, lungs, pulmonary arteries, right ventricle, right atrium, venae cavae C. Venae cavae, right atrium, right ventricle, pulmonary arteries, lungs, pulmonary veins, left atrium, left ventricle, aorta D. Aorta, left ventricle, left atrium, pulmonary veins, lungs, pulmonary arteries, right atrium, right ventricle, venae cavae E. None of the listed responses is correct.

C. Venae cavae, right atrium, right ventricle, pulmonary arteries, lungs, pulmonary veins, left atrium, left ventricle, aorta

By picking up hydrogen ions, hemoglobin prevents the blood from becoming too _____. A. acidic B. basic C. thick D. low in oxygen concentration E. red

A. acidic

Double circulation circulatory systems are found in ________, and single circulation circulatory systems are found in ________. A. amphibians; fish B. fish; mammals C. fish; reptiles D. sharks; rays E. insects; mammals

A. amphibians; fish

Most carbon dioxide is carried from the body tissues to the lungs _____. A. as bicarbonate ions (HCO3 -) B. combined with hemoglobin C. by the trachea D. as hydrogen ions (H+) E. dissolved in blood plasma

A. as bicarbonate ions (HCO3 -)

The smallest airway through which inspired air passes before gas exchange occurs in the mammalian lungs is the _____. A. bronchiole B. trachea C. larynx D. bronchus E. pharynx

A. bronchiole

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

A. heart rate

Heart valves function to __________. A. keep blood moving in the correct direction B. mix blood thoroughly as it passes through the heart C. propel blood as it passes through the heart D. slow blood down as it passes through the heart E. control the amount of blood pumped by the heart

A. keep blood moving in the correct direction

Which chamber(s) of a human heart receive(s) and pump(s) oxygenated blood? A. left ventricle and left atrium B. left atrium only C. right atrium and right ventricle D. left atrium and right atrium E. left ventricle only

A. left ventricle and left atrium

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? A. Although diffusion is random, the result will be the net movement of X from B to A. B. Because diffusion is random, diffusion will take place without changing the concentration of X in either A or B. C. There will be no net movement of X because there is no energy available to transport X from B to A. D. There will be no net movement of X because the total amount of X is the same in A and B.

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

Which of the following is the main factor that causes lymph to move through lymphatic vessels? A. Contractions of body muscles near lymph vessels B. Osmotic pressure C. Blood pressure D. Contractions of capillaries E. Diffusion

A. Contractions of body muscles near lymph vessels

Which of the following maximizes gas exchange in the gills of a bony fish? A. Countercurrent exchange B. A tracheal system C. Positive pressure breathing D. Negative pressure breathing E. Alveoli

A. Countercurrent exchange

Cellular respiration A. produces CO2 and ATP. B. takes place in specialized organelles called chloroplasts. C. synthesizes sugars from CO2 and H2O. D. uses O2 and CO2 as raw materials.

A. produces CO2 and ATP.

From the superior vena cava, blood flows to the _____. A. right atrium B. left atrium C. aorta D. capillaries of the lungs E. inferior vena cava

A. right atrium

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. the trachea. C. the right atrium. D. the right ventricle. E. an alveolus.

A. the pulmonary vein.

Which of the following decreases blood pressure? A. vasodilation B. contraction of the ventricles of the heart C. vasoconstriction D. the peptide endothelin E. All of the listed responses are correct.

A. vasodilation

Impulses are delayed briefly at the _______ and are then transmitted through special fibers to the base of the ventricles. Strong contractions begin at the apex of the heart and drive blood up and out of the heart.

AV node

When the ventricles contract, the _________ snap closed.

AV valves

Which of the following factors would increase the release of oxygen from hemoglobin? A. Decreased exercise and increased blood pH B. Increased exercise and decreased blood pH C. Decreased blood PO2 and increased blood pH D. Increased blood pH and increased blood PO2 E. Decreased blood PO2 and decreased exercise

B. Increased exercise and decreased blood pH Decreased blood pH and PO2 would increase the release of oxygen from hemoglobin. An increase in exercise and a decrease in blood pH would increase the release of oxygen from hemoglobin. Although decreased blood PO2 would cause an increase in the release of oxygen from hemoglobin, decreased exercise would not. Although decreased blood PO2 would cause an increase in the release of oxygen from hemoglobin, increased blood pH would not.

Which of the following statements correctly describes one of the differences between open and closed circulatory systems? A. Open circulatory systems separate the blood from the interstitial fluid, whereas the two mix in closed circulatory systems. B. Open circulatory systems are less costly than closed circulatory systems in terms of energy expenditure. C. None of the listed responses is correct. D. In a closed circulatory system, chemical exchange occurs between hemolymph and body cells, but in an open circulatory system, chemical exchange occurs between the blood and the interstitial fluid. E. Closed circulatory systems produce relatively low blood pressure, whereas open circulatory systems produce high blood pressure.

B. Open circulatory systems are less costly than closed circulatory systems in terms of energy expenditure.

Which of the following statements correctly describes some of the differences between arteries and veins? A. The walls of arteries are much thinner than the walls of veins. B. The walls of arteries are much thicker and stronger than the walls of veins. C. Arteries contain valves, but veins do not. D. Blood pressure in veins is higher than it is in arteries. E. Arteries carry oxygen-poor blood, and veins carry oxygen-rich blood.

B. The walls of arteries are much thicker and stronger than the walls of veins.

An open circulatory system __________. A. has no valves B. is less common in crabs and beetles than in mice and snakes C. allows interstitial fluid to mix freely with vascular fluid D. restricts the backflow of blood by valves in the trachea E. unlike a closed circulatory system, does not rely on muscle contraction

C. allows interstitial fluid to mix freely with vascular fluid

What would you expect to see in an individual with low levels of blood protein in the capillaries? A. decreased lymph B. a net gain of fluid in the capillaries C. edema in the body tissues D. increased movement of fluid into the capillaries from the extracellular environment E. increased blood pressure

C. edema in the body tissues The lack of sufficient proteins in the capillaries will decrease the osmotic pressure, resulting in an accumulation of fluid in the body tissues.

Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arteries has a A. lower osmotic pressure. B. lower pH. C. higher P(O2). D. greater bicarbonate concentration. E. higher P(CO2).

C. higher P(O2).

Blood returns to the heart via the _____. A. aorta B. pulmonary arteries C. pulmonary veins D. aorta and pulmonary arteries E. aorta and pulmonary veins

C. pulmonary veins

If resistance increases in the capillary beds of the lung, which structure would be affected first? A. Left ventricle B. Left atrium C. Right atrium D. Right ventricle E. Aorta

D. Right ventricle

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

D. the tracheal system of an insect

Pressure is greatest in the ventricles when __________. A. blood arrives at the left atrium B. blood arrives at the right ventricle C. the atria contract during early systole D. the ventricles contract E. AV valves are open and semilunar valves are closed

D. the ventricles contract

Which of the following is a function of the circulatory system? A. producing mucus B. producing wastes C. eliminating hormones D. transporting nutrients E. All of the listed responses are correct.

D. transporting nutrients

During the phase of the cardiac cycle called _________ , the entire heart is relaxed and blood flows into all four chambers.

Diastole

What is the physiological cause of a heart attack? A. Scar tissue in the heart muscle B. Rupture of coronary arteries C. A blood clot moving through the chambers of the heart D. Severe angina E. A blood clot lodging in a blood vessel supplying the heart

E. A blood clot lodging in a blood vessel supplying the heart

All of the following statements are correct regarding respiratory surfaces except which one? A. Movement of gases across respiratory surfaces occurs by diffusion. B. Respiratory surfaces must be moist. C. Respiratory surfaces have a large surface area. D. Respiratory surfaces are thin. E. Respiratory surfaces must be dry.

E. Respiratory surfaces must be dry.

From the capillaries of the abdominal organs and hind limbs, blood flows to the _____. A. right atrium B. left atrium C. aorta D. capillaries of the lungs E. inferior vena cava

E. inferior vena cava

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

E. left atrium.

To control breathing, the medulla of the human brain monitors the ________ of the blood and then sends out signals so that appropriate physiological adjustments can be made. A. erythrocyte count B. oxygen level C. carbon dioxide level D. hemoglobin level E. pH

E. pH

Why do larger animals, such as a bullfrog, require a circulatory system, but animals such as a planarian do not? A. Diffusion is inadequate to move gases through the body surface and into all parts of a larger animal body. However, diffusion alone is sufficient to move gases in and out of the thin body of a planarian. B. Gases do not diffuse through bone. Therefore, any animal with bones, such as a bullfrog, has to have a circulatory system. Any animal without bones, such as a planarian, does not have a circulatory system. C. Each cell in a bullfrog requires more oxygen and nutrients than each cell in a planarian. D. The cells of a bullfrog are many times larger than the cells of a planarian. E. None of the listed responses is correct.

A. Diffusion is inadequate to move gases through the body surface and into all parts of a larger animal body. However, diffusion alone is sufficient to move gases in and out of the thin body of a planarian.

How are gases transported in insect bodies? A. In tracheal systems B. In closed circulatory systems C. In open circulatory systems

A. In tracheal systems

What is the function of a circulatory system? A. It brings a transport liquid into close contact with all cells in the body. B. It exchanges oxygen and carbon dioxide with the outside air. C. It is the site of blood cell production. D. It acts as a reservoir for the storage of blood.

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

What is unique about blood in pulmonary arteries compared with blood in other arteries? A. It is loaded with carbon dioxide. B. It is moving away from the heart. C. There is no difference; it is the same as blood in other arteries. D. Blood in pulmonary arteries is always blue; it is red in all other arteries. E. It is moving toward the heart.

A. It is loaded with carbon dioxide.

What is unique about blood in pulmonary arteries compared with blood in other arteries? A. It is loaded with carbon dioxide. B. Blood in pulmonary arteries is always blue; it is red in all other arteries. C. It is moving toward the heart. D. It is moving away from the heart. E. There is no difference; it is the same as blood in other arteries.

A. It is loaded with carbon dioxide.

Imagine that you are walking to class and a person on a bicycle comes very close to hitting you. Your heart begins to beat faster. Which of the following structures is responsible for this reaction? A. The SA node B. The AV valve C. The Purkinje fibers D. The semilunar valves E. The AV node

A. The SA node The AV node is the point for the relay of signals from the SA node to the ventricles. The Purkinje fibers spread electrical signals throughout the ventricles. The semilunar valves are not involved in the control of heart rhythm. The AV valve is not involved in the control of heart rhythm.

Why do the circulatory systems of land vertebrates have separate circuits to the lungs and to the rest of the body? A. The large decrease in blood pressure as blood moves through the lungs may prevent efficient circulation through the rest of the body. B. Land vertebrates are bigger and require more tubing to reach all areas of the body. C. Blood is pumped to the lungs to be oxygenated before being pumped to the rest of the body. D. The circuits increase the amount of surface area available for the diffusion of gases and nutrients in the body.

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

Select the correct statement about the three-chambered hearts of amphibians and nonbird reptiles. A. The three-chambered hearts of amphibians and nonbird reptiles are facultative, allowing variation in blood flow through the heart. B. The three-chambered heart is inferior to the four-chambered hearts of birds and mammals, limiting the evolutionary success of amphibians and nonbird reptiles. C. Pulmonary and systemic blood fully mixes in the ventricle of a three-chambered heart.

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

Which event of the cardiac cycle occurs when systolic blood pressure is measured? A. The ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria. B. The atria and ventricles contract simultaneously. C. The atria and ventricles are relaxed, and blood flows into the atria. D. The atria contract while blood flows into the relaxed ventricles.

A. The ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria. The systolic blood pressure is the peak blood pressure, resulting from contraction of the ventricles.

How many chambers are typically found in the heart of organisms with single circulation circulatory systems? A. Two B. Three C. Five D. Four E. One

A. Two

Which of the following statements about blood circulation in the body is true? A. Valves prevent the backflow of blood into the atria and ventricles. B. Deoxygenated blood flowing through the pulmonary veins is carried to the right atrium. C. As the right ventricle contracts, it sends oxygenated blood through the aorta to all tissues of the body. D. During one cardiac cycle, the two ventricles contract first, and then the two atria contract.

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

Stroke occurs when _____. A. a blood clot enters the cerebral circulation, blocking an artery and causing the death of brain tissue B. the walls of an artery in the leg accumulate deposits and lose their flexibility and elasticity C. a blood clot dislodges from a vein and moves into the lung, where it blocks a pulmonary artery D. a blood clot enters and blocks one of the coronary arteries E. the pacemaker of the heart becomes defective, producing an irregular heartbeat

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

An open circulatory system __________. A. unlike a closed circulatory system, does not rely on muscle contraction B. allows interstitial fluid to mix freely with vascular fluid C. restricts the backflow of blood by valves in the trachea D. has no valves E. is less common in crabs and beetles than in mice and snakes

B. allows interstitial fluid to mix freely with vascular fluid

Your blood pressure is 120/70. The "120" indicates __________, and the "70" indicates __________. A. pressure in the systemic system; pressure in the pulmonary system B. arterial pressure during heart contraction; arterial pressure during heart relaxation C. arterial pressure; venous pressure D. pressure in the left ventricle; pressure in the left atrium E. pressure in the left ventricle; pressure in the right ventricle

B. arterial pressure during heart contraction; arterial pressure during heart relaxation

In the blood most of the oxygen that will be used in cellular respiration is carried from the lungs to the body tissues _____. A. as bicarbonate ions (HCO3 -) B. combined with hemoglobin C. by the trachea D. water (H2O) E. dissolved in blood plasma

B. combined with hemoglobin

From the pulmonary veins, blood flows to the _____. A. right atrium B. left atrium C. aorta D. capillaries of the lungs E. inferior vena cava

B. left atrium

The volume of air inhaled and exhaled with each breath is called _______. A. residual volume B. tidal volume C. tidal capacity D. vital capacity E. None of the listed responses is correct.

B. tidal volume

All of the following increase blood pressure except _______. A. vasoconstriction B. vasodilation C. lower total cross-sectional area of blood vessels D. ventricular contraction E. endothelin

B. vasodilation

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

E. rising CO2

Which of the following would increase the release of oxygen from red blood cells? A. an increase in pH and a decrease in the PO2 B. an increase in pH and an increase in the PO2 C. a decrease in pH and a decrease in the PO2 D. a decrease in pH and an increase in the PO2 E. None of the listed responses is correct.

C. a decrease in pH and a decrease in the

_____ in carbon dioxide in your red blood cells, which causes _____ in pH, causes your breathing to speed up. A. An increase ... a rise B. A decrease ... a drop C. A decrease ... a rise D. An increase ... a drop E. Actually, it is the rise and fall of oxygen, not carbon dioxide, that controls breathing.

D. An increase ... a drop

Patients with leukemia, a type of cancer that affects the blood, often exhibit suppressed immunity and problems with blood clotting. Based on these two symptoms, which components of the blood are affected by this type of cancer? A. Plasma proteins and ions B. Plasma proteins and leukocytes C. Platelets and erythrocytes D. Platelets and leukocytes E. Erythrocytes and plasma proteins

D. Platelets and leukocytes

A(n) ______ records the electrical changes that occur during the heartbeat and provides data on the health of the heart.

ECG/EKG

Which event occurs first during atrial and ventricular diastole? A. The atria and ventricles contract simultaneously. B. Blood flows into the relaxed atria while the ventricles contract. C. The atria contract while blood flows into the relaxed ventricles. D. The atria and ventricles are relaxed, and blood flows into the atria.

D. The atria and ventricles are relaxed, and blood flows into the atria. Diastole is the relaxation phase of the cardiac cycle during which the chambers of the heart are relaxed and blood can enter them passively.

All known birds and mammals have ________. A. a double circulatory system and a three-chambered heart B. a single circulatory system and a four-chambered heart C. a double circulatory system and a two-chambered heart D. a double circulatory system and a four-chambered heart E. a single circulatory system and a two-chambered heart

D. a double circulatory system and a four-chambered heart

When you exhale, __________. A. the volume of the chest cavity increases B. the diaphragm relaxes and the lungs expand C. both the diaphragm and rib muscles contract D. both the diaphragm and the rib muscles relax E. the rib muscles contract and the air pressure in the alveoli becomes lower than atmospheric pressure

D. both the diaphragm and the rib muscles relax

Voice sounds are produced by the _____. A. trachea B. diaphragm C. bronchioles D. larynx E. lungs

D. larynx

The primary functions of the _____ are to warm, filter, and humidify air. A. lungs B. trachea C. bronchus D. nasal cavity E. alveoli

D. nasal cavity

What happens when the CO2 level from cellular respiration increases in the blood? A. Cellular respiration decreases. B. The medulla, moderated by the pons, signals the heart muscle to beat harder, bringing in more O2. C. The O2 level automatically increases. D. The pH of the cerebrospinal fluid also increases and is detected by O2 sensors in arteries near the heart. E. A decrease in the pH of the cerebrospinal fluid triggers the brain's breathing control centers, which stimulate diaphragm and rib muscle contractions.

E. A decrease in the pH of the cerebrospinal fluid triggers the brain's breathing control centers, which stimulate diaphragm and rib muscle contractions.

Which of the following pairs correctly matches the blood component with one of its functions? A. Erythrocytes; immunity B. Platelets; pH buffering C. Ions; lipid transport D. Leukocytes; blood clotting E. Plasma proteins; osmotic balance

E. Plasma proteins; osmotic balance Erythrocytes function in oxygen and carbon dioxide transport. Leukocytes function in immunity. Platelets function in blood clotting. Ions in the blood help maintain pH and osmotic balance and regulate membrane permeability.

Which statement about human blood vessels is correct? A. Veins transport blood from the heart to the capillaries. B. The pulmonary artery carries oxygen-rich blood from the lungs. C. Arteries carry oxygenated blood; veins carry oxygen-poor blood. D. Arteries carry blood toward the atria of the heart. E. Pulmonary veins carry oxygen-rich blood to the heart.

E. Pulmonary veins carry oxygen-rich blood to the heart.

Which of the following is a function of the circulatory system? A. Eliminating hormones B. Producing wastes C. All of the listed responses are correct. D. Producing mucus E. Transporting nutrients

E. Transporting nutrients

Gas exchange in the lungs of mammals occurs in the __________. A. bronchi B. larynx C. trachea D. bronchioles E. alveoli

E. alveoli

A mutation that results in a nonfunctioning nitric oxide receptor would cause __________. A. decreased vasoconstriction B. increased vasoconstriction C. decreased blood pressure D. increased vasodilation E. decreased vasodilation

E. decreased vasodilation The effect of nitric oxide binding to its receptor is vasodilation and a subsequent fall in blood pressure; the inability of the receptor to bind NO would decrease the likelihood of vasodilation occurring.

In which of the following animals are the blood and the interstitial fluid considered to be the same body fluid? A. dogs B. jellyfish and cnidarians C. sparrows D. fishes E. grasshoppers

E. grasshoppers Within an open circulatory system, such as that operating in insects, the body fluid, called hemolymph, bathes the organs directly as it is pumped between open spaces in the body.

The amount of oxygen bound to hemoglobin _____. A. increases as the pH of tissues decreases B. is called the Bohr shift C. decreases in the presence of high concentrations of oxygen D. increases with increasing acidity at the tissue level E. increases in the presence of high concentrations of oxygen

E. increases in the presence of high concentrations of oxygen

True or false? The circulatory systems of land-dwelling vertebrates are composed of two pumping circuits: the systemic circulation, which is a lower-pressure circuit to the lung, and the pulmonary circulation, which is a higher-pressure circuit to the rest of the body. True False

False. The pulmonary circulation is the lower-pressure circuit to the lung, whereas the systemic circulation is the higher-pressure circuit to the rest of the body.

The ______ , or pacemaker, initiates the heartbeat by generating electrical impulses that spread across both atria.

SA node

During the phase of the cardiac cycle called _________, the heart contracts beginning with the atria and then the ventricles.

Systole

A defective heart valve can be identified by the sound of a(n) ______.

heart murmur