BIOD 152 LAB 4 EXAM 2026 | CIRCULATORY SYSTEM & BLOOD FLOW TRACINGS QUESTIONS

BIOD 152 LAB 4 EXAM 2026 | CIRCULATORY
SYSTEM & BLOOD FLOW TRACINGS
QUESTIONS
BIOD 152 LAB 4 EXAM 2026 | CIRCULATORY SYSTEM & BLOOD FLOW TRACINGS

• This comprehensive exam contains 200 carefully constructed multiple-choice
questions designed to test your understanding of heart anatomy, blood vessel
function, and blood flow pathways through the circulatory system.

• Use this material to reinforce laboratory observations, practice identifying cardiac
structures and tracing blood flow through various circuits, and prepare for clinical
applications of circulatory physiology.



Question 1: Which chamber of the heart receives deoxygenated blood from
the systemic circulation?

A) Left ventricle

B) Right atrium

C) Left atrium

D) Right ventricle

E) Pulmonary trunk

CORRECT ANSWER: B) Right atrium receives deoxygenated blood from the
systemic circulation via the superior and inferior vena cava.

RATIONALE: The right atrium serves as the receiving chamber for deoxygenated
blood returning from the body. The superior vena cava drains blood from the
upper body and head, while the inferior vena cava drains blood from the lower
body. This deoxygenated blood is then pumped into the right ventricle during atrial
contraction. The left atrium receives oxygenated blood from the lungs, while the
ventricles are contractile chambers that pump blood out of the heart.



Question 2: What is the primary function of the bicuspid valve?

A) Prevents backflow of blood from the right atrium to the superior vena cava

,B) Prevents backflow of blood from the left ventricle to the left atrium

C) Allows one-way flow from the right atrium to the left atrium

D) Prevents backflow into the aorta

E) Allows blood flow from the right ventricle to the pulmonary artery

CORRECT ANSWER: B) The bicuspid valve prevents backflow of blood from the
left ventricle to the left atrium.

RATIONALE: The bicuspid valve (also called the mitral valve) is located between the
left atrium and left ventricle. During ventricular contraction, it closes to prevent
blood from flowing backward into the left atrium, ensuring unidirectional blood
flow through the heart. This valve consists of two cusps and is the only valve in the
heart with two cusps. A weak or damaged bicuspid valve can lead to mitral
regurgitation.



Question 3: Which blood vessels carry oxygenated blood from the lungs to the
heart?

A) Pulmonary arteries

B) Pulmonary veins

C) Coronary arteries

D) Superior vena cava

E) Inferior vena cava

CORRECT ANSWER: B) Pulmonary veins carry oxygenated blood from the lungs
to the heart.

RATIONALE: The pulmonary veins are unique in that they carry oxygenated blood,
whereas most veins carry deoxygenated blood. Four pulmonary veins (two from
each lung) enter the left atrium, delivering freshly oxygenated blood for distribution
to the body through the aorta. In contrast, pulmonary arteries carry deoxygenated
blood from the right ventricle to the lungs for oxygenation. This is the only

,exception to the general rule that arteries carry oxygenated blood and veins carry
deoxygenated blood.



Question 4: During the QRS complex on an ECG, what is occurring in the
heart?

A) Atrial depolarization

B) Ventricular repolarization

C) Ventricular depolarization

D) Atrial repolarization

E) Ventricular relaxation

CORRECT ANSWER: C) The QRS complex represents ventricular depolarization.

RATIONALE: The QRS complex is the large, sharp deflection on an ECG that occurs
when the ventricles depolarize. This electrical activity precedes ventricular
contraction (systole), which pumps blood out of the heart. The QRS complex
typically lasts 0.08-0.12 seconds. The P wave represents atrial depolarization, and
the T wave represents ventricular repolarization. Understanding the components of
an ECG is essential for identifying normal cardiac rhythms and various arrhythmias.



Question 5: Which of the following correctly describes the path of blood flow
through the right side of the heart?

A) Right atrium → right ventricle → pulmonary artery → lungs

B) Right atrium → pulmonary artery → right ventricle → lungs

C) Lungs → right atrium → right ventricle → pulmonary artery

D) Right ventricle → right atrium → pulmonary artery → lungs

E) Pulmonary artery → right atrium → right ventricle → lungs

, CORRECT ANSWER: A) Right atrium → right ventricle → pulmonary artery →
lungs correctly describes the path of blood flow through the right side of the
heart.

RATIONALE: Deoxygenated blood enters the right atrium from the systemic
circulation, is pumped into the right ventricle through the tricuspid valve, and then
is ejected through the pulmonary valve into the pulmonary artery, which carries it
to the lungs for oxygenation. This is the pulmonary circulation. Understanding this
pathway is fundamental for tracing blood flow through the heart and recognizing
any disruptions in this normal pattern.



Question 6: The semilunar valves of the heart include which of the following?

A) Tricuspid and bicuspid valves

B) Pulmonary and aortic valves

C) Mitral and tricuspid valves

D) Pulmonary and tricuspid valves

E) Bicuspid and tricuspid valves

CORRECT ANSWER: B) The semilunar valves are the pulmonary and aortic
valves.

RATIONALE: Semilunar valves have three cusps that are shaped like half-moons
(semi = half, lunar = moon). The pulmonary valve is located between the right
ventricle and the pulmonary artery, while the aortic valve is located between the
left ventricle and the aorta. Both valves prevent backflow of blood into the
ventricles during ventricular diastole. In contrast, the tricuspid and bicuspid valves
are atrioventricular valves located between the atria and ventricles.



Question 7: What is the normal heart rate range for a healthy adult at rest?

A) 40-60 beats per minute

B) 60-100 beats per minute