Deck 32: Circulation

Question 1

Which statement about capillaries is true?

A) Capillaries are the principle sites in closed circulatory systems where blood releases oxygen,nutrient molecules,and hormones.
B) Oxygen must diffuse across 2-10 layers of epithelial cells to exit capillaries and reach its target cells.
C) Capillaries are more numerous than arterioles but less numerous than venules.
D) The lumen of capillaries is large enough for 2-10 red blood cells to flow adjacent to one another.
E) Capillaries are only found near specialized brain and lung cells.

Answer 1

A

Question 2

Atherosclerosis is hardening of the arteries caused by

A) exposure to radiation.
B) red blood cell deposits.
C) the removal of cholesterol.
D) an increase in muscle cells.
E) fatty deposits.

Answer 2

E

Question 3

In fish,blood circulates through _______ circuit(s),whereas in mammals,it circulates through _______ circuit(s).

A) one complete;two complete
B) two complete;two partial
C) one partial;two complete
D) two complete;four complete
E) four complete;one partial

Answer 3

A

Question 4

The benefit of having at least a partial separation of pulmonary and systemic circulation is that

A) oxygenated and deoxygenated blood do not mix.
B) blood moving to the body tissues is at a higher pressure than it would be if it had flowed directly from the lungs to the body.
C) blood moving to the lungs is at a higher pressure than it would be if it had come directly from the body.
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 5

A premature baby in critical condition with high blood pressure in his lungs is administered a blend of nitric oxide (a vasodilator)and oxygen to reduce his blood pressure.Nitric oxide reduces blood pressure by

A) constricting the muscle cells around arterioles.
B) reducing the heart rate.
C) blocking the formation of new capillaries.
D) relaxing the muscle cells around arterioles.
E) increasing the formation of capillaries.

Question 6

The probability of developing atherosclerosis is increased by

A) a high-fat diet.
B) snoring.
C) living at a high altitude.
D) excessive alcohol consumption.
E) excessive exercising.

Question 7

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

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

Question 8

The breathing-organ circuit in a horse

A) transports oxygen to the lungs.
B) transports oxygen to the brain.
C) exchanges carbon dioxide for oxygen in the lungs.
D) carries food waste away from the heart.
E) removes waste from the heart.

Question 9

In arthropods,the exchange of substances between the blood and tissue cells occurs

A) in the arteries.
B) in the arterioles.
C) in the capillaries.
D) in the venules.
E) directly.

Question 10

The circulatory system of a crayfish includes all of the following except

A) heart.
B) arteries.
C) sinuses and lacunae.
D) veins bringing blood into the heart.
E) blood.

Question 11

Pseudoephedrine is a vasoconstriction drug that is commonly used in cold medications to alleviate nasal congestion.Its mechanism of action most likely involves

A) contraction of arteriole muscle cells.
B) relaxation of arteriole muscle cells.
C) swelling of red blood cells.
D) closing of the valves that lead from capillaries to arterioles.
E) formation of additional capillaries when needed.

Question 12

What is one advantage of closed circulatory systems as compared to open circulatory systems?

A) Transport is slower in closed systems,increasing the time for gas exchange.
B) Closed systems have a higher capacity to direct blood to specific tissues.
C) In closed systems,cells and large molecules can mix with nutrients absorbed in the intestines and directly feed all cells.
D) In closed systems,there is no distinction between blood and interstitial fluid.
E) Closed systems use less energy.

Question 13

Which statement about the open circulatory system of a crayfish is false?

A) A pump is present.
B) Blood is returned to the heart in veins.
C) The blood is part of the interstitial fluid.
D) Interstitial fluid bathes the tissues directly.
E) Crayfish have many arteries,which extend forward and backward from the heart.

Question 14

A circulatory system's sophistication

A) is often correlated with a species' need for gas transport.
B) is often correlated with a species' need for food transport.
C) is not correlated with any metabolic functions.
D) varies depending on the current environment conditions an organism lives in.
E) depends on the amount of CO₂ in the lungs.

Question 15

A typical circulatory system consists of

A) a muscular pump only.
B) a muscular pump,a fluid,and a series of conduits.
C) blood and blood vessels only.
D) a fluid and a series of conduits only.
E) blood,spicules,and trachea.

Question 16

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 17

In animals with an open circulatory system,the liquid responsible for gas exchange with the cells is called

A) blood plasma.
B) extracellular fluid.
C) mesolymph.
D) blood.
E) hemoblood.

Question 18

Which animal has an open circulatory system?

A) Bat
B) Earthworm
C) Human
D) Lobster
E) Lizard

Question 19

Which animal has a circulatory plan in which blood flows from the heart through the breathing-organ circuit,then through the systemic circuit,and then back to the heart?

A) Sockeye salmon
B) Polar bear
C) Bluebird
D) Red-ear slider turtle
E) Everglades rat snake

Question 20

In an open circulatory system,

A) there is no heart.
B) blood does not pass through the gills.
C) there are no blood vessels.
D) hemolymph flows out of the body.
E) there is no distinction between hemolymph and interstitial fluid.

Question 21

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 22

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 23

How does blood flow in pulmonary arteries differ from that in other arteries?

A) Pulmonary arteries transport oxygen-depleted blood to the heart from the lungs,whereas other arteries transport oxygen-rich blood away from the heart.
B) Pulmonary arteries transport oxygen-depleted blood away from the heart,whereas other arteries transport oxygen-rich blood away from the heart.
C) Pulmonary arteries transport oxygen-rich blood away from the heart,whereas other arteries transport oxygen-depleted blood away from the heart.
D) Pulmonary arteries are located in the lungs,whereas other arteries are located in the brain and heart.
E) Pulmonary arteries transport lymph,whereas other arteries transport blood.

Question 24

Which sequence represents the correct order of blood flow in the fish circulatory system?

A) Heart $\rightarrow$ gills $\rightarrow$ systemic tissues
B) Heart $\rightarrow$ systemic tissues $\rightarrow$ gills
C) Heart $\rightarrow$ systemic tissues $\rightarrow$ gills $\rightarrow$ systemic tissues
D) Systemic tissues $\rightarrow$ heart $\rightarrow$ gills $\rightarrow$ heart
E) Heart $\rightarrow$ systemic tissues

Question 25

Oxygenated blood is carried by the

A) aorta.
B) pulmonary vein.
C) pulmonary artery.
D) superior vena cava.
E) Both a and b

Question 26

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

A) pulmonary artery.
B) inferior vena cava.
C) superior vena cava.
D) pulmonary vein.
E) coronary artery.

Question 27

In humans,the _______ empties into the right atrium.

A) inferior vena cava
B) pulmonary vein
C) superior vena cava
D) pulmonary artery
E) Both a and c

Question 28

Which sequence represents the correct order of blood flow in the mammalian circulatory system?

A) Heart $\rightarrow$ lungs $\rightarrow$ systemic tissues
B) Heart $\rightarrow$ systemic tissues $\rightarrow$ lungs
C) Heart $\rightarrow$ systemic tissues $\rightarrow$ lungs $\rightarrow$ systemic tissues
D) Systemic tissues $\rightarrow$ heart $\rightarrow$ lungs $\rightarrow$ heart
E) Heart $\rightarrow$ lungs $\rightarrow$ heart $\rightarrow$ systemic tissues

Question 29

The amphibian heart

A) pumps only oxygenated blood.
B) pumps only oxygen-depleted blood.
C) pumps both oxygenated and oxygen-depleted blood.
D) has a completely divided ventricle to prevent mixing of oxygenated and oxygen-depleted blood.
E) is a single circulatory loop system.

Question 30

A paleontologist finds a fragment of a fossilized vertebrate that had a four-chambered heart with two atria and two ventricles.The animal could have been a

A) shark.
B) turtle.
C) frog.
D) heron.
E) lizard.

Question 31

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

A) Fish
B) Lungfish
C) Amphibian
D) Cheetah
E) Bird

Question 32

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) tuna.
B) lizard.
C) primate.
D) eagle.
E) crayfish.

Question 33

Mammalian and bird hearts

A) pump only oxygenated blood.
B) pump only oxygen-depleted blood.
C) pump both oxygenated and oxygen-depleted blood but the two do not mix in the heart.
D) have only partially divided ventricles,to allow mixing of oxygenated and oxygen-depleted blood.
E) is a single circulatory loop system.

Question 34

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

A) contraction;relaxation;ventricles
B) relaxation;contraction;ventricles
C) relaxation;contraction;atria
D) contraction;relaxation;atria
E) polarization;depolarization;S-A and A-V nodes

Question 35

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

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

Question 36

A myogenic heart

A) requires nervous stimulation in order to beat.
B) has a beat that is initiated within the myocardium.
C) is found in humans.
D) is found in lobsters.
E) Both b and c

Question 37

During the cardiac cycle in mammals,the blood pressure in the aorta is greatest

A) during diastole.
B) when the atria contract.
C) when the aortic and pulmonary valves are closed.
D) during systole.
E) when the atrioventricular valves are open.

Question 38

Which statement about vertebrate circulatory systems is false?

A) In fish,oxygenated blood from the gills returns to the heart through the left atrium.
B) In amphibians,blood from the systemic tissues enters the heart through the right atrium.
C) In reptiles,the blood in the pulmonary artery has a lower oxygen content than the blood in the aorta.
D) In birds,the pressure in the aorta is higher than the pressure in the pulmonary artery.
E) In mammals,deoxygenated blood leaves the heart through the pulmonary artery.

Question 39

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 40

The circulatory system of an earthworm circulates blood

A) by the pumping action of multiple four-chambered hearts.
B) by peristaltic waves generated by contraction of muscular blood vessels.
C) using an open circulatory system.
D) using one centrally located heart.
E) through the heart,to the lungs,back to the heart,and out to the systemic tissues.

Question 41

(Small diameter)× (very large number)= the reason that _______ are the blood vessels with more total cross-sectional area than the other blood vessels listed.

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

Question 42

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

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

Question 43

Atrial fibrillation occurs when the heart begins generating electrical impulses due to faulty signals originating in more than one area of the heart.What region of the heart that normally controls the rhythm of the heartbeat is being overridden in patients with atrial fibrillation?

A) Atriventricular node
B) Sinoatrial node
C) Aorta
D) Pulmonary valve
E) Common carotid artery

Question 44

Which statement about the heartbeat in mammals is true?

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

Question 45

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

A) the sinoatrial node.
B) the atrioventricular node.
C) modified muscle cells of the conducting system.
D) systolic contractions.
E) the ventricular mass.

Question 46

Biologists are studying the anatomy of a newly discovered whale whose carcass has washed up on shore.In examining a cross section of its flipper,they notice a vein and an artery running in parallel.The artery can be distinguished from the vein because the artery has

A) a larger interior diameter.
B) more muscle tissue and elastin in the wall.
C) a lining of vascular endothelium.
D) valves to prevent backflow.
E) All of the above

Question 47

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 48

A patient with a family history of heart disease has an EKG every year.Her latest EKG indicates her heart rate has slowed since her last visit.How would the QRS complex of her most recent EKG compare to that of her previous EKG?

A) The QRS complex would be the same as in previous years.
B) The R-peak within the QRS complex would be missing.
C) The QRS complex would have switched places with the P waves.
D) The R-peaks of successive QRS complexes would be spread farther apart.
E) There would be more QRS complexes.

Question 49

A patient feels faint and has low blood pressure.An echocardiogram of the heart shows that the atrioventricular valve between the left atrium and left ventricle does not close completely,a condition called mitral valve prolapse.This can result in low blood pressure,because with each heartbeat the left ventricle is

A) overfilling with blood during each cardiac cycle.
B) pumping less blood than normal to the lungs.
C) pumping more blood than normal to the lungs.
D) pushing more blood than normal out to the systemic circuit.
E) pushing less blood than normal out to the systemic circuit.

Question 50

What is the correct order in which action potentials spread during a normal heartbeat in the mammalian heart?

A) Sinoatrial node $\rightarrow$ atrioventricular node $\rightarrow$ atrium $\rightarrow$ ventricle
B) Atrioventricular node $\rightarrow$ atrium $\rightarrow$ ventricle $\rightarrow$ sinoatrial node
C) Conducting system $\rightarrow$ atrioventricular node $\rightarrow$ ventricle $\rightarrow$ atrium
D) Sinoatrial node $\rightarrow$ conducting system $\rightarrow$ atrioventricular node
E) Sinoatrial node $\rightarrow$ atrium $\rightarrow$ atrioventricular node $\rightarrow$ conducting system $\rightarrow$ ventricle

Question 51

Defective heart valves that do not close completely could result in

A) oxygen-rich blood mixing with oxygen-depleted blood.
B) increased pulmonary flow.
C) venous gas exchange within the heart chambers.
D) atrial exchange of excess blood.
E) some blood flowing back into the atrium with each heartbeat.

Question 52

Blockage of a coronary artery can be the direct cause of

A) a heart attack.
B) a stroke.
C) fainting.
D) edema.
E) anemia.

Question 53

Blood is at its lowest pressure in the

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

Question 54

In the electrocardiogram (EKG)record of a normal cardiac cycle shown below,wave T corresponds to _______ of the _______.

A) depolarization;atria
B) depolarization;ventricles
C) repolarization;atria
D) repolarization;ventricles
E) Both a and b

Question 55

Which statement about the crustacean circulatory system is false?

A) A heart is usually present.
B) Blood is pumped out of openings in the heart called ostia.
C) Blood is pumped out of the heart into arteries.
D) Crustaceans have a single-chambered heart.
E) The heart is stimulated to beat by nerve impulses.

Question 56

Damage to valves in veins would

A) increase the amount of blood returning to the heart.
B) result in brain swelling.
C) decrease the amount of blood returning to the heart.
D) have no effect of blood returning to the heart.
E) cause blood to flow to the lung.

Question 57

The blood vessels with valves are

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

Question 58

An artificial pacemaker can be implanted in patients whose natural pacemaker is malfunctioning,causing an excessively slow or irregular heartbeat.In order for the artificial pacemaker to ensure proper cardiac rhythm,the electrical leads should be implanted

A) in the middle of the left ventricle.
B) in the brain.
C) in the middle of the aorta.
D) in the wall of the right atrium.
E) at the atrioventricular node.

Question 59

As blood travels from the arteries of the heart into the capillaries of the body tissue,blood pressure drops precipitously.Which statement about the relationship between cross-sectional vessel area and blood pressure is true?

A) As the total cross-sectional area decreases,blood pressure also decreases.
B) As the total cross-sectional area increases,blood pressure also increases.
C) As the total cross-sectional area increases,blood pressure decreases.
D) As the total cross-sectional area decreases,blood pressure increases.
E) There is no relationship between cross-sectional vessel area and blood pressure.

Question 60

The pacemaker function in the mammalian heart is performed by the

A) sinoatrial node.
B) atrioventricular node.
C) conducting fibers.
D) bundle fibers.
E) ventricular mass.

Question 61

The lifetime of an individual red blood cell is approximately

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

Question 62

Which of the following is not a mechanism that facilitates return of venous blood to the heart?

A) Gravity,for veins that 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

During exercise,additional O₂ is delivered to cells by increased

A) circulation only.
B) release of O₂ from hemoglobin only.
C) circulation and increased release of O₂ from hemoglobin.
D) release of O₂ from hemoglobin and lowered cellular demand.
E) circulation and lowered cellular demand.

Question 64

In organisms with a closed circulatory system,the liquid surrounding cells in the body is called _______ fluid.

Question 65

Hemoglobin and hemocyanin

A) are both used by vertebrates to transport O₂.
B) both have iron-containing proteins.
C) are blue when oxygen levels are low and red when oxygen levels are high.
D) are found inside blood cells.
E) both transport oxygen.

Question 66

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 67

In open circulatory systems,the fluid called _______ leaves the vessels of the circulatory system before flowing over the organs.

Question 68

Platelets

A) prevent a histamine reaction from occurring when a person is stung by a wasp.
B) activate leukocytes.
C) combine with oxygen to make hemoglobin.
D) aid blood clotting to prevent excess bleeding.
E) are broken pieces of white blood cells.

Question 69

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) lymphocytes and other cells of the immune system help fight infection.

Question 70

Which statement about the function of blood is false?

A) It transports O₂ and CO₂.
B) It transports body heat to where it is most needed.
C) It produces red blood cells.
D) It acts as a buffer to changes in pH.
E) It transports nutrients to cells.

Question 71

Normal blood is composed of all the following components except

A) platelets.
B) plasma.
C) arterioles.
D) white blood cells.
E) red blood cells.

Question 72

Which statement about veins is false?

A) Blood pressure is very low in veins,necessitating one-way valves to prevent backflow.
B) Contractions of skeletal muscles squeeze the veins,which move blood to the heart.
C) The walls of veins are more expandable than the walls of arteries.
D) Veins serve as a blood reservoir.
E) As blood flows from the capillaries to the veins and back to the heart,the linear velocity slows to almost zero.

Question 73

Arthropods,many mollusks,and some other invertebrates have a(n)_______ circulatory system.

Question 74

The most abundant cells in vertebrate blood are

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

Question 75

How is most CO₂ transported in blood?

A) CO₂ reacts with water in the blood to form bicarbonate ions.
B) Bicarbonate interacts with water to produce CO₂.
C) O₂ binds with the CO₂ to produce bicarbonate ions.
D) Hemoglobin binds the CO₂ to produce bicarbonate ions.
E) Hemocyanin and hemoglobin bind CO₂ and O₂ to form copper.

Question 76

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) Lymphatic vessels contain one-way valves.
E) Lymph nodes are an important part of the defense system that combats infections.

Question 77

Countercurrent heat exchange allows animals to

A) minimize heat loss to their environment.
B) keep their hearts warm enough to pump blood.
C) live in extremely hot dessert environments.
D) slow down food digestion.
E) absorb heat from their environment.

Question 78

Lymphatic vessels are like veins in that both

A) have nodes where they join larger common vessels.
B) carry blood under low pressure.
C) move their fluids by contraction of small muscular bands.
D) have valves.
E) empty into the heart.

Question 79

Blood pressure is _______ osmotic pressure at the arterial end of a capillary bed,causing fluids to move _______ the blood.

A) greater than;into
B) greater than;out of
C) lesser than;into
D) lesser than;out of
E) equal to;into

Question 80

Blood pressure is _______ osmotic pressure at the venule end of a capillary bed,causing fluids to move _______ the blood.

A) greater than;into
B) greater than;out of
C) lesser than;into
D) lesser than;out of
E) equal to;into