Question 1

Red blood cells are

Accepted Answer

A)   biconcave cells containing hemoglobin.
B)   spherical cells containing hemoglobin.
C)   spherical cells capable of amoeboid motion and containing hemoglobin.
D)   biconcave cells containing platelets.
E)   biconcave cells that function in the immune response.F) All of the above
G) D) and E)

Question 2

Which of the following is not a risk factor for developing atherosclerosis?

Accepted Answer

A)   A high-fat and high-cholesterol diet
B)   Smoking
C)   High altitude
D)   Inactive lifestyle
E)   HypertensionF) A) and D)
G) All of the above

Question 3

Which of the following statements about valves is false?

Accepted Answer

A)   Defective heart valves produce sounds called heart murmurs.
B)   Veins and lymphatic vessels have two-way valves.
C)   Varicose veins result when valves within veins can no longer prevent backflow of blood.
D)   The pulmonary valve is located between the right ventricle and the pulmonary artery.
E)   Atrioventricular valves prevent backflow of blood into the atria when the ventricles contract.F) A) and B)
G) None of the above

Question 4

The circulating protein fibrinogen contributes to blood clotting by

Accepted Answer

A)   polymerizing to form fibrin threads.
B)   acting as a catalyst for thrombin activation.
C)   binding to red blood cells.
D)   activating the platelets.
E)   triggering phagocytosis by the leukocytes.F) A) and B)
G) A) and C)

Question 5

In the evolution of the vertebrate circulatory system, a transitional step led to separate pulmonary and systemic circuits. This step can be observed in

Accepted Answer

A)   lungfish.
B)   the ancient ostracoderm.
C)   birds.
D)   amphibians.
E)   reptiles.F) B) and D)
G) A) and E)

Question 6

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

Accepted Answer

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

Question 7

Lymph nodes are sites

Accepted Answer

A)   where bacteria can grow.
B)   where inflammation occurs.
C)   that regulate blood fluid.
D)   where new cells enter.
E)   of mechanical filtering.F) B) and C)
G) All of the above

Question 8

Which of the following statements about the lymphatic system is false?

Accepted Answer

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)   Contraction of skeletal muscles propels the lymph.
E)   Lymph nodes are an important part of the defense system that combats infections.F) B) and D)
G) A) and B)

Question 9

Histamine causes inflammation by

Accepted Answer

A)   making blood vessels expand and decreasing the permeability of capillaries.
B)   making blood vessels contract and decreasing the permeability of capillaries.
C)   making blood vessels expand and increasing the pressure in capillaries.
D)   decreasing the permeability of and increasing the pressure in capillaries.
E)   increasing the permeability of and the pressure in capillaries.F) A) and B)
G) B) and E)

Question 10

A blood pressure represented as 140/100 means that the

Accepted Answer

A)   pressure during ventricular contraction is 140, while the pressure during ventricular relaxation is 100.
B)   pressure during ventricular contraction is 100, while the pressure during ventricular relaxation is 140.
C)   pressure during ventricular contraction is 140, while the pressure during atrial contraction is 100.
D)   pressure during atrial contraction is 140, while the pressure during ventricular contraction is 100.
E)   diastolic pressure is 140 and the systolic pressure is 100.F) C) and D)
G) A) and B)

Question 11

Refer to the graph below of ventricular muscle fiber membrane activity. Which of the following statements is false?

Accepted Answer

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

Question 12

Why is an open circulatory system less efficient than a closed circulatory system?

Accepted Answer

A)   It is more difficult to deliver O2 to specific tissues when needed.
B)   There is no heart to pump the blood.
C)   Open circulatory systems lack hemoglobin.
D)   Nutrients cannot be delivered to tissues in an open circulatory system.
E)   All of the aboveF) B) and C)
G) A) and C)

Question 13

Which of the following is not an advantage of closed circulatory systems as compared to open systems?

Accepted Answer

A)   Closed systems move wastes and nutrients more quickly.
B)   Molecules specialized as carriers of hormones and nutrients can be stored in closed systems when not in use.
C)   As certain tissues experience a greater need for respiratory gases, closed systems can prioritize the delivery of gases to them.
D)   In hermaphroditic species, closed systems can deliver gametes from one set of sex organs directly to the other.
E)   As certain tissues experience a greater need for nutrients, closed systems can prioritize the delivery of nutrients to them.F) A) and B)
G) A) and C)

Question 14

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

Accepted Answer

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

Question 15

Which of the following statements about blood cells is false?

Accepted Answer

A)   There are at least 500 times as many red as white blood cells.
B)   Erythrocytes are anucleate in mammals.
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 spleen.
E)   Leukocytes destroy foreign cells.F) A) and B)
G) A) and C)

Question 16

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

Accepted Answer

A)   Right atrium
B)   Left atrium
C)   Aorta
D)   Ventricle
E)   Pulmonary veinF) A) and D)
G) D) and E)

Question 17

Many animals with open circulatory systems are relatively inactive. Explain how insects, with their open circulatory systems, maintain their high levels of activity.

Accepted Answer

Despite having an open circulatory syste...

Question 18

The lymphatic system empties intercellular fluid into the _______ ducts, which empty into large veins at the base of the neck.

Accepted Answer

The answer of The lymphatic system empties intercellular fluid into...

Question 19

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

Accepted Answer

A)   high resistance to outside stimulation.
B)   cell communication via gap junctions.
C)   a low level of electrical activity.
D)   an external pacemaking system.
E)   rapid chemical communication.F) A) and E)
G) A) and D)

Question 20

Which is the correct sequence of parts through which cardiac action potentials pass?

Accepted Answer

A)   Purkinje fibers, AV node, SA node, bundle of His, atrial fibers
B)   AV node, atrial fibers, SA node, bundle of His, Purkinje fibers
C)   SA node, bundle of His, atrial fibers, AV node, Purkinje fibers
D)   Purkinje fibers, bundle of His, AV node, atrial fibers, SA node
E)   SA node, atrial fibers, AV node, bundle of His, Purkinje fibersF) A) and C)
G) D) and E)

Exam 50: Circulatory Systems

Which of the following statements about the lymphatic system is false?

Correct AnswerverifiedShow Answer

Histamine causes inflammation by

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

Correct AnswerverifiedShow Answer

Why is an open circulatory system less efficient than a closed circulatory system?

Correct AnswerverifiedShow Answer

Which of the following statements about valves is false?

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

Correct AnswerverifiedShow Answer

Many animals with open circulatory systems are relatively inactive. Explain how insects, with their open circulatory systems, maintain their high levels of activity.

Correct AnswerverifiedDespite having an open circulatory syste...View AnswerShow Answer

Which of the following is not an advantage of closed circulatory systems as compared to open systems?

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The lymphatic system empties intercellular fluid into the _______ ducts, which empty into large veins at the base of the neck.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

A blood pressure represented as 140/100 means that the

Correct AnswerverifiedShow Answer

Lymph nodes are sites

Correct AnswerverifiedShow Answer

In the evolution of the vertebrate circulatory system, a transitional step led to separate pulmonary and systemic circuits. This step can be observed in

Correct AnswerverifiedShow Answer

Which of the following statements about blood cells is false?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The circulating protein fibrinogen contributes to blood clotting by

Correct AnswerverifiedShow Answer

Which is the correct sequence of parts through which cardiac action potentials pass?

Correct AnswerverifiedShow Answer

Which of the following is not a risk factor for developing atherosclerosis?

Correct AnswerverifiedShow Answer

Red blood cells are

Correct AnswerverifiedShow Answer

Refer to the graph below of ventricular muscle fiber membrane activity. Which of the following statements is false?

Correct AnswerverifiedShow Answer

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

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Despite having an open circulatory syste...
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When submerged, frogs receive most of their O₂ from capillaries within the skin. Which of the following structures would contain blood with the highest O₂ concentration in a submerged frog that is not able to breathe using its lungs?

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