Deck 49: Circulatory Systems

Question 1

Refer to the table. Complete the table by correctly matching adult vertebrate groups to their heart structures, from first row to last row.

A) Crocodilians, water-breathing fishes, mammals, birds, turtles
B) Amphibians, birds, water-breathing fishes, turtles, lungfishes
C) Lungfishes, turtles, water-breathing fishes, crocodilians, amphibians
D) Amphibians, turtles, water-breathing fishes, lungfishes, crocodilians
E) Water-breathing fishes, lungfishes, amphibians, crocodilians, turtles

Answer 1

D

Question 2

Which of the following does not characterize open circulatory systems?

A) They include a heart that moves extracellular fluid through vessels.
B) Fluid may return to the heart through ostia.
C) They are present in small aquatic vertebrates.
D) They are found in arthropods and mollusks.
E) Hemolymph percolates through tissues.

Answer 2

C

Question 3

In animals with a closed circulatory system, the liquid around the body cells is called

A) blood plasma.
B) interstitial fluid.
C) mesolymph.
D) hemolymph.
E) intracellular fluid.

Answer 3

B

Question 4

Which of the following is not an advantage of closed circulatory systems?

A) They have better control of blood flow to specific tissues.
B) Special cells that transport oxygen remain in vessels but can drop off oxygen where needed.
C) Extracellular fluid is the same as the fluid in the circulatory system.
D) They allow more rapid transport of substances.
E) Specialized molecules that transport hormones remain in vessels and eventually drop off their cargo.

Question 5

Some relatively large multicellular aquatic animals have no circulatory system.One way that these organisms manage gas exchange is by

A) bringing the external environment into a branched system of channels such that most cells are close to that environment.
B) hosting endosymbiotic bacteria that produce oxygen inside their tissues.
C) breathing air into a set of lungs.
D) basking at the surface periodically to allow for diffusion of oxygen.
E) having long diffusion distances.

Question 6

Which statement about circulatory systems is false?

A) In closed circulatory systems, "extracellular fluid" refers to the fluid inside and outside the circulatory system.
B) Hearts move extracellular fluid through the body.
C) In closed circulatory systems, the fluid inside the circulatory system is blood plasma.
D) Hemolymph remains in the vessels of open circulatory systems.
E) In closed circulatory systems, interstitial fluid is outside the circulatory system.

Question 7

A paleontologist finds a fragment of a fossilized vertebrate that indicates that the adult animal had a four-chambered heart arranged in a single circuit.The animal could have been a(n)

A) fish.
B) amphibian.
C) crocodile.
D) bird.
E) mammal.

Question 8

Which statement about open circulatory systems is false?

A) A pump is usually present.
B) In arthropods, blood is pumped out of openings in the heart called ostia.
C) The hemolymph is part of the extracellular fluid.
D) Interstitial fluid bathes the tissues directly.
E) They are found in mollusks and arthropods.

Question 9

Which of the following is not transported in a closed circulatory system?

A) Heat
B) Respiratory gases
C) Hormones
D) Hemolymph
E) Cells of the immune system

Question 10

In vertebrates, exchange of substances between the blood and the interstitial fluid occurs in the

A) arteries.
B) arterioles.
C) capillaries.
D) veins.
E) venules.

Question 11

In the water-breathing fish circulatory system, blood

A) moves from the muscular ventricle to the bulbus arteriosus to the gills.
B) enters the aorta under high pressure.
C) leaves the heart and moves directly to body tissues.
D) leaves the gills under high pressure.
E) is received from the body directly into a muscular atrium.

Question 12

In what way is a closed circulatory system more efficient than an open circulatory system?

A) A closed circulatory system is a closed loop and therefore does not require a heart for pumping blood.
B) An open circulatory system relies on diffusion to deliver nutrients to tissues.
C) A closed circulatory system relies on hemoglobin rather than on myoglobin.
D) In a closed circulatory system, blood vessels can control the delivery of O₂ to specific tissues by controlling vessel diameter.
E) A closed circulatory system keeps hemolymph separate from interstitial fluid.

Question 13

Which animals would be the best for illustrating the evolutionary transition of the vertebrate circulatory system from a single loop system to one with separate pulmonary and systemic circuits?

A) Lungfishes
B) Mammals
C) Birds
D) Amphibians
E) Reptiles

Question 14

In an open circulatory system,

A) there is no heart.
B) there is a gastrovascular cavity.
C) there are no blood vessels.
D) hemolymph flows out of the body.
E) there is no distinction between hemolymph and extracellular fluid.

Question 15

Which of the following is not found in an open circulatory system?

A) Extracellular fluid
B) Heart
C) Vessels
D) Blood plasma
E) Hemolymph

Question 16

Which feature does not characterize the circulatory system of water-breathing fishes?

A) Single atrium
B) Blood leaving the gills returning to the heart for additional pumping before entering the systemic circuit
C) Single ventricle
D) Blood leaving the gills and entering the aorta under low pressure
E) Single circuit

Question 17

A paleontologist finds a fragment of a fossilized vertebrate that indicates that the animal had a three-chambered heart.The animal could have been a(n)

A) fish.
B) amphibian.
C) crocodile.
D) bird.
E) mammal.

Question 18

Which group of vertebrates is phylogenetically oldest and retains the ancestral type of heart?

A) Reptiles
B) Amphibians
C) Fishes
D) Birds
E) Mammals

Question 19

The genus Hydra contains small invertebrates related to the jellyfishes.All of the following characteristics of the genus make it unnecessary for these animals to have a cardiovascular system except

A) being aquatic.
B) having no skeleton.
C) consisting of only two cell layers.
D) being small.
E) being primarily sedentary.

Question 20

Which of these features do(es) not characterize animals without a circulatory system?

A) Single-celled
B) Small and thin
C) Aquatic with a gastrovascular cavity
D) Large body size and very active
E) Relatively large and sedentary

Question 21

A blood pressure reading from a sphygmomanometer is measured in millimeters of mercury.For a reading of 140/100, for example, the first number represents _______ and the second number represents _______.

A) pressure during ventricular contraction; pressure during ventricular relaxation
B) pressure during ventricular relaxation; pressure during ventricular contraction
C) pressure during ventricular contraction; pressure during atrial contraction
D) pressure during atrial contraction; pressure during ventricular contraction
E) diastolic pressure; systolic pressure

Question 22

A benefit of having at least a partial separation of pulmonary and systemic circulation, as found in amphibians, is that

A) oxygenated and deoxygenated blood are separated.
B) blood moving to the body tissues is at a higher pressure than it would be if it had flowed through the lungs first.
C) blood moving to the lungs is at a lower pressure than it would be if it had come directly from the body without flowing through the heart first.
D) blood moving to the body tissues is at a lower pressure than it would be if it had flowed through the lungs first.
E) there are two muscular regions for pumping.

Question 23

Refer to the figure, which shows the mammalian circulatory system.The arrow indicates the direction of blood flow. The right atrium is indicated at which point (1-4)?

A) 1
B) 2
C) 3
D) 4
E) The right atrium is not represented in the diagram.

Question 24

Which structure or region in or connected to a four-chambered mammalian heart contains blood with the lowest O₂ concentration?

A) Pulmonary vein
B) Pulmonary artery
C) Left atrium
D) Aorta
E) Arteriole end of a systemic capillary

Question 25

Which vertebrate has a three-chambered heart with both pulmonary and systemic circuits?

A) Water-breathing fish
B) Lungfish
C) Amphibian
D) Crocodilian
E) Bird

Question 26

Which structure or region in or connected to a four-chambered mammalian heart contains blood with the highest O₂ concentration?

A) Right atrium
B) Pulmonary vein
C) Pulmonary artery
D) Superior vena cava
E) Right ventricle

Question 27

In humans, the _______ empty into the right atrium.

A) pulmonary vein and aorta
B) inferior vena cava and superior vena cava
C) aorta and common iliac vein
D) pulmonary artery and pulmonary vein
E) common iliac vein and aorta

Question 28

Which statement about the cardiac cycle in mammals is true?

A) Only the ventricles contract in unison.
B) Only the atria contract in unison.
C) The atria contract in unison and the ventricles contract in unison.
D) Only the atrium and ventricle on the right side of the heart contract in unison.
E) Only the atrium and ventricle on the left side of the heart contract in unison.

Question 29

As compared with the circulatory system of most fishes, the circulatory system of adult amphibians has the advantage of

A) a four-chambered heart.
B) two aortas.
C) a partial separation between pulmonary and systemic circulation.
D) a pocket of the gut that serves as an air bladder.
E) complete separation of oxygenated and deoxygenated blood.

Question 30

Refer to the figure, which shows the cardiac cycle in mammals. During the cardiac cycle, the blood pressure in the aorta is at a minimum

A) at the end of systole.
B) in the middle of diastole.
C) at the beginning of diastole.
D) when the "dup" sound can be heard with a stethoscope.
E) when the volume of blood in the ventricles is at its maximum.

Question 31

When submerged, frogs receive most of their O₂ from capillaries within their skin.Which structure is likely to contain blood with the highest O₂ concentration in a submerged frog that is not able to breathe using its lungs?

A) Right atrium
B) Left atrium
C) Aorta
D) Ventricle
E) Pulmonary vein

Question 32

In the cardiac cycle of humans, blood pressure is at its maximum when the _______ are _______ during _______.

A) atria; contracting; systole
B) atria; contracting; diastole
C) ventricles; contracting; systole
D) ventricles; relaxing; systole
E) ventricles; relaxing; diastole

Question 33

Refer to the figure, which shows the mammalian circulatory system.The arrow indicates the direction of blood flow. The left ventricle is indicated at which point (1-4)?

A) 1
B) 2
C) 3
D) 4
E) The left ventricle is not represented in the diagram.

Question 34

"Systole" and "diastole" refer to the _______ and _______, respectively, of the _______ in mammals.

A) relaxation; contraction; ventricles
B) contraction; relaxation; ventricles
C) relaxation; contraction; atria
D) contraction; relaxation; atria
E) contraction; relaxation; semi-lunar valves

Question 35

Heart murmurs result from defective

A) heart muscle.
B) arterioles.
C) ventricular contraction.
D) blood supply to the heart.
E) heart valves.

Question 36

A paleontologist finds a fragment of a fossilized vertebrate that indicates that the animal had a four-chambered heart with two atria and two ventricles; it also had two aortas, one emerging from each ventricle.The animal could have been a(n)

A) fish.
B) amphibian.
C) crocodile.
D) bird.
E) mammal.

Question 37

The left ventricle in humans is more muscular than the right ventricle because

A) resistance is higher in the systemic circuit.
B) resistance is higher in the pulmonary circuit.
C) the left ventricle pumps more total blood.
D) the left ventricle pumps more viscous blood.
E) the lymphatic system empties into the left ventricle.

Question 38

In the human heart, blood is pumped from the left ventricle into the

A) right ventricle.
B) left atrium.
C) right atrium.
D) pulmonary circuit.
E) systemic circuit.

Question 39

In humans, oxygenated blood is transported from the lungs to the heart by the

A) pulmonary arteries.
B) inferior vena cava.
C) superior vena cava.
D) pulmonary veins.
E) coronary arteries.

Question 40

Crocodilians differ from other (nonavian) reptiles in that they have

A) separate pulmonary circulation.
B) lungs and no gills.
C) an open circulatory system.
D) more muscular atria.
E) a four-chambered heart.

Question 41

Refer to the graph, which shows ventricular muscle fiber membrane activity. Which statement about the graph is false?

A) The activity shown in curve 1 is initiated by the opening of voltage-gated sodium channels.
B) Curve 1 depicts an action potential for ventricular muscle.
C) The extended plateau of curve 1 is due to sustained opening of voltage-gated calcium channels.
D) The activity shown in curve 2 depicts the relative permeability of the membrane to sodium ions.
E) The activity shown in curve 3 depicts the relative permeability of the membrane to potassium ions.

Question 42

The lifetime of an individual red blood cell in humans is approximately

A) 4 hours.
B) 4 days.
C) 4 weeks.
D) 40 days.
E) 4 months.

Question 43

Which represents the correct order in which action potentials spread from the atria to the ventricles during a normal heartbeat in the mammalian heart?

A) Atrioventricular node $\rightarrow$ bundle of His $\rightarrow$ Purkinje fibers
B) Atrioventricular node $\rightarrow$ Purkinje fibers $\rightarrow$ bundle of His
C) Purkinje fibers $\rightarrow$ bundle of His $\rightarrow$ atrioventricular node
D) Sinoatrial node $\rightarrow$ Purkinje fibers $\rightarrow$ bundle of His
E) Sinoatrial node $\rightarrow$ ventricular muscle cells $\rightarrow$ Purkinje fibers

Question 44

Refer to the figure, which shows an electrocardiogram (ECG). In the ECG of a normal cardiac cycle, the wave called T corresponds to _______ of the _______.

A) depolarization; atria
B) depolarization; ventricles
C) repolarization; atria
D) repolarization; ventricles
E) relaxation; atria

Question 45

Refer to the figure. What are the names of the structures labeled 2 and 4, respectively?

A) Bundle of His; atrioventricular node
B) Bundle of His; Purkinje fibers
C) Purkinje fibers; sinoatrial node
D) Sinoatrial node; atrioventricular node
E) Purkinje fibers; Bundle of His

Question 46

Gap junctions

A) electrically isolate cardiac muscle cells.
B) allow large numbers of cardiac muscle cells to contract in unison.
C) provide enough strength to withstand the large pressure generated by the ventricles.
D) are found only in the cardiac muscle cells of the ventricles.
E) block the spread of action potentials.

Question 47

Which statement about red blood cells is false?

A) Production of red blood cells is controlled by erythropoietin.
B) Red blood cells are produced by stem cells in the kidneys.
C) Erythropoietin extends the lives of mature red blood cells.
D) Macrophages ingest remnants of red blood cells in the spleen.
E) Red blood cells are packed with hemoglobin.

Question 48

Which is the incorrect match between blood component and function.

A) Erythrocytes: transport O₂ and CO₂
B) Leukocytes: produce antibodies
C) Platelets: play a role in blood clotting
D) Erythrocytes: transport nutrients
E) Leukocytes: play a role in allergic responses

Question 49

Refer to the graph, which shows ventricular muscle fiber membrane activity. Which statement about the graph is false?

A) Curve 1 depicts an action potential for ventricular muscle.
B) The sudden drop in curve 3 as it approaches 0.30 seconds is due to a closing of calcium channels.
C) The activity shown in these curves reflects the movement of positively charged ions.
D) The activity shown in these curves reflects the movement of negatively charged ions.
E) The activity shown in these curves depends on the opening or closing of voltage-gated channels.

Question 50

The pacemaker function in the mammalian heart is performed by the

A) sinoatrial node.
B) atrioventricular node.
C) Purkinje fibers.
D) bundle of His.
E) ventricular mass.

Question 51

Which statement about blood cells is false?

A) The body contains many more red blood cells than white blood cells.
B) Mammal erythrocytes do not have nuclei
C) The biconcave shape of the erythrocyte creates a large surface area for gas exchange.
D) Red blood cells are generated by stem cells in the lymph nodes.
E) Leukocytes destroy foreign cells.

Question 52

In women, the normal hematocrit, or percentage of the blood made up of red blood cells, is about _______ percent.

A) 10
B) 25
C) 42
D) 70
E) 90

Question 53

The timing of the spread of the action potential from atrium to ventricle is controlled by the

A) sinoatrial node.
B) atrioventricular node.
C) Purkinje fibers.
D) bundle of His.
E) ventricular mass.

Question 54

The heart beats because of cardiac muscle's specialized properties, such as

A) high resistance to outside stimulation.
B) an external pacemaker system.
C) a low level of electrical activity.
D) cell communication via gap junctions.
E) rapid communication through release of neurotransmitters between cells.

Question 55

The hormone erythropoietin is released by the kidney

A) to remove old red blood cells from circulation.
B) in response to high levels of oxygen in circulation.
C) in response to low levels of hemoglobin.
D) to stimulate production of red blood cells.
E) to stimulate platelet formation.

Question 56

Refer to the figure, which shows an electrocardiogram (ECG). In the (ECG) of a normal cardiac cycle, which peak or trough corresponds to the relaxation of the ventricles?

A) P
B) Q
C) R
D) S
E) T

Question 57

The most abundant cells in mammalian blood are

A) erythrocytes.
B) leukocytes.
C) phagocytes.
D) platelets.
E) megakaryocytes.

Question 58

When whole blood is centrifuged, it is separated into a liquid component called _______ and a bottom layer of _______.

A) hematocrit; cells
B) plasma; cells
C) plaque; cells
D) hematocrit; plasma
E) packed cell volume; plasma

Question 59

The mature red blood cells of humans

A) contain no nuclei or endoplasmic reticulum.
B) are more than 75 percent hemoglobin.
C) have a nearly spherical shape.
D) have a relatively low surface area-to-volume ratio.
E) have a rigid shape and low flexibility.

Question 60

Refer to the figure. Based on the figure, which represents the correct direction of the formation of the heartbeat?

A) 1 $\rightarrow$ 2 $\rightarrow$ 3 $\rightarrow$ 4 $\rightarrow$ 5 $\rightarrow$ 6 and 7
B) 1 $\rightarrow$ 3 $\rightarrow$ 6 and 7 $\rightarrow$ 2 $\rightarrow$ 4 $\rightarrow$ 5
C) 1 $\rightarrow$ 6 and 7 $\rightarrow$ 5 $\rightarrow$ 4 $\rightarrow$ 3 $\rightarrow$ 2
D) 1 $\rightarrow$ 6 and 7 $\rightarrow$ 3 $\rightarrow$ 2 $\rightarrow$ 4 $\rightarrow$ 5
E) 6 $\rightarrow$ 5 $\rightarrow$ 4 $\rightarrow$ 3 $\rightarrow$ 2 $\rightarrow$ 7 and 1

Question 61

The blood vessels with the greatest capacity to store blood are the

A) arteries.
B) arterioles.
C) capillaries.
D) veins.
E) venules.

Question 62

Which mechanism is not one of the mechanisms that facilitates the return of venous blood to the heart?

A) Gravity, when veins are above the heart
B) Contraction of skeletal muscles
C) Breathing
D) Contraction of smooth muscle in most veins of the body
E) Valves in veins

Question 63

The function of platelets is to

A) destroy foreign cells or to produce antibodies.
B) transport respiratory gases.
C) stimulate blood clotting.
D) distribute nutrients to tissues.
E) produce the different types of blood cells.

Question 64

Which statement about the forces that affect movement across walls of capillaries is false?

A) Osmotic pressure pulls water back into capillaries.
B) At the venule end of a capillary bed, there is a net outward force.
C) Blood osmotic pressure is due to large protein molecules that remain within capillaries.
D) Blood hydrostatic pressure is high at the arterial end of a capillary bed.
E) Blood pressure squeezes water and small solutes out of capillaries.

Question 65

(Small diameter) × (very large number) = the reason that _______ have the greatest total cross-sectional area of all the blood vessel types.

A) arteries
B) arterioles
C) capillaries
D) venules
E) veins

Question 66

The diameter of a capillary is about the same as that of a(n)

A) arteriole.
B) nerve.
C) red blood cell.
D) valve.
E) venule.

Question 67

A platelet is activated to initiate clotting

A) during an allergic reaction.
B) when leukocytes are activated.
C) when it encounters collagen fibers.
D) when blood flow rates drop.
E) in the presence of prothrombin.

Question 68

Lymph nodes are sites where

A) lymph vessels join the venous system.
B) nerve cell bodies innervating the lymphatic system are concentrated.
C) the amount of fluid in the blood is regulated.
D) new red blood cells are produced.
E) microorganisms and foreign materials are removed by phagocytosis.

Question 69

Which statement about the lymphatic system is false?

A) The lymphatic system conducts lymph from the lymph capillaries to the thoracic duct, where it enters the circulatory system.
B) Lymph is identical to blood except that it does not contain erythrocytes.
C) Lymphoid capillaries are distributed throughout the body.
D) Lymph is propelled by contraction of skeletal muscles.
E) Lymph nodes are an important part of the defense system that combats infections.

Question 70

Blood pressure is _______ than osmotic pressure at the arterial end of a capillary bed, which is where the process of _______ occurs.

A) greater; resorption
B) greater; filtration
C) lesser; resorption
D) lesser; filtration
E) lesser; edema

Question 71

The smooth muscle around arterioles can

A) relax in response to high O₂ levels.
B) relax in response to high blood pH.
C) shut off the supply of blood to the capillary bed.
D) relax in response to low CO₂ levels.
E) contract to increase local blood flow to a tissue.

Question 72

Blood is at its lowest pressure in the

A) arteries.
B) arterioles.
C) capillaries.
D) venules.
E) veins.

Question 73

A patient suffers from excessive bleeding whenever he gets cut.The patient is not a hemophiliac.It is likely, therefore, that this patient's symptom is caused by

A) liver disease.
B) atherosclerosis.
C) arteriosclerosis.
D) a myocardial infarction.
E) an embolism.

Question 74

The carcass of a newly discovered deep-diving species of whale washes up on shore, and biologists scramble to study the adaptations that allow this species to circulate blood when it is under pressure at depth.A cross section of its flipper shows what seem to be a vein and an artery running parallel.The artery would be the structure

A) with the largest interior diameter.
B) with more muscle tissue and elastin in the wall.
C) lined with endothelium.
D) with valves to prevent backflow.
E) with an outer connective tissue layer.

Question 75

Refer to the graph, which shows blood pressure, blood velocity, and area of the blood vessels throughout a human circulatory system. Which of the statement about the graph is false?

A) Curve 1 traces blood velocity, curve 2 traces blood pressure, and curve 3 traces blood vessel area.
B) Curve 3 represents total area.
C) The vessels represented on the left of the graph have many extracellular collagen and elastin fibers in their walls.
D) The vessels represented to the left of capillaries on the graph are referred to as resistance vessels.
E) Exchanges of nutrients, respiratory gases, and hormones occur where curve 3 is at its maximum point.

Question 76

Below the level of the heart, the movement of blood in the veins toward the heart is caused primarily by

A) gravity.
B) the contraction of venous walls.
C) cilia lining the veins.
D) the contraction of nearby skeletal muscles.
E) venous capacitance.

Question 77

Refer to the graph, which shows blood pressure, blood velocity, and area of the blood vessels throughout a human circulatory system. Which of the statement about the graph is false?

A) The vessels represented on the left of the graph have many extracellular collagen and elastin fibers in their walls.
B) The rise in curve 2 on the right side of the graph is caused by rhythmic contraction of smooth muscles surrounding the veins.
C) The vessels represented on the far right of the graph are referred to as capacitance vessels.
D) Fluid may be drawn back into the blood vessels represented on the right side of curve 3 by a high osmotic potential.
E) The vessels represented on the far right of the graph may hold 60 percent of a person's blood at any given time.

Question 78

The Frank-Starling law suggests that during exercise, the

A) flow of blood through the heart speeds up.
B) heart is stretched and contracts more forcefully.
C) veins expand to handle increased blood flow.
D) heart fills to capacity with blood at each beat.
E) valves in veins cannot prevent backflow.

Question 79

Which statement about veins is false?

A) Veins may hold as much as 60 percent of total blood volume at any one time.
B) Veins are capacitance vessels.
C) The walls of veins are more expandable than the walls of arteries.
D) Blood in veins below the level of the heart is moved toward the heart by contractions of surrounding skeletal muscles.
E) The muscles involved in exhalation help pull blood toward the chest.

Question 80

The circulating protein fibrinogen contributes to blood clotting by

A) forming fibrin threads.
B) acting as a catalyst for thrombin activation.
C) binding to red blood cells.
D) activating the platelets.
E) cleaving collagen fibers.