Question 1

Which of the following best describes the main function of the circulatory system in vertebrates?

Accepted Answer

To facilitate the exchange of gases, nutrients, and wastes between cells and the external environment.

Question 2

Which structure in the human heart prevents the backflow of blood from the left ventricle to the left atrium during ventricular contraction?

Accepted Answer

The mitral (bicuspid) valve

Question 3

During the cardiac cycle, which phase is characterized by the relaxation of the heart and the opening of the atrioventricular (AV) valves?

Accepted Answer

Diastole

Question 4

Which node acts as the primary pacemaker of the human heart, setting the tempo for the cardiac cycle?

Accepted Answer

Sinoatrial (SA) node

Question 5

A patient presents with a heart murmur due to mitral valve prolapse. Which of the following is a likely consequence?

Accepted Answer

Regurgitation of blood from the left ventricle into the left atrium

Question 6

Which of the following equations correctly represents the relationship between blood pressure, cardiac output, and resistance in the circulatory system?

Accepted Answer

$$P = CO 	imes R$$

Question 7

Which blood vessel type has the greatest total cross-sectional area and the slowest blood flow velocity, facilitating exchange with tissues?

Accepted Answer

Capillaries

Question 8

A patient is diagnosed with atherosclerosis. Which process is most directly impaired by this condition?

Accepted Answer

Blood flow through arteries due to plaque buildup

Question 9

Which of the following best explains why veins have valves while arteries do not?

Accepted Answer

Veins operate under lower pressure and require valves to prevent backflow of blood.

Question 10

Which blood component is primarily responsible for forming clots to stop bleeding after vessel injury?

Accepted Answer

Platelets

Question 11

A patient with leukemia has an abnormal increase in which type of blood cell?

Accepted Answer

White blood cells

Question 12

Which of the following best describes the role of precapillary sphincters in regulating blood flow?

Accepted Answer

They control the distribution of blood into capillary beds by contracting or relaxing.

Question 13

Which of the following is a correct sequence of blood flow through the human heart and major vessels?

Accepted Answer

Right atrium → right ventricle → pulmonary artery → lungs → left atrium → left ventricle → aorta

Question 14

Which of the following is a direct effect of sympathetic nervous system activation on the heart?

Accepted Answer

Increased heart rate and force of contraction

Question 15

Which of the following best explains the difference between open and closed circulatory systems?

Accepted Answer

Closed systems have blood confined to vessels, while open systems have hemolymph bathing tissues directly.

Question 16

A blood pressure reading of 120/70 mmHg is taken using a sphygmomanometer. What do the numbers represent?

Accepted Answer

120 mmHg is systolic pressure; 70 mmHg is diastolic pressure.

Question 17

Which of the following is the correct formula for calculating cardiac output ($$CO) in $$terms of heart rate ($$HR) $$and stroke volume ($$SV$$)?

Accepted Answer

$$CO = HR 	imes SV$$

Question 18

Which of the following best describes the role of fibrin in blood clot formation?

Accepted Answer

Fibrin forms a mesh that stabilizes the platelet plug and traps blood cells.

Question 19

A patient experiences a stroke due to an embolus. Which of the following best describes what has occurred?

Accepted Answer

A blood clot traveled through the bloodstream and blocked a vessel in the brain.

Chapter 30: Circulation – The Circulatory System in General Biology

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드