BIO 117 – Hondros Exam 3 (2025) – Updated Actual Exam with Correct
Solutions
Question 1
The apex of the heart is anatomically located at the:
A) Right second intercostal space.
B) Left second intercostal space.
C) Fifth intercostal space, pointing down towards the left.
D) Third intercostal space, at the sternal border.
E) Base of the heart, near the great vessels.
Correct Answer: C) 5th intercostal space
Rationale: The apex of the heart is the pointed, inferior portion that typically extends
downwards and to the left, locating it in the fifth intercostal space, often just medial to the
midclavicular line.
Question 2
Which layer of the heart wall is primarily responsible for its pumping action?
A) Endocardium.
B) Epicardium.
C) Myocardium.
D) Pericardium.
E) Visceral pericardium.
Correct Answer: C) Myocardium
Rationale: The myocardium is the thick, muscular middle layer of the heart wall. It contains
cardiac muscle cells that contract to pump blood, making it the primary functional layer
for the heart's pumping action.
Question 3
What is the anatomical description of the apex of the heart?
A) The superior portion where the great vessels emerge.
B) The posterior surface, resting on the diaphragm.
C) The tip of the heart, pointing down towards the left 5th intercostal space.
D) The broad, flat superior portion.
E) The medial aspect, adjacent to the sternum.
Correct Answer: C) The tip of the heart, pointing down towards the left 5th intercostal
space.
Rationale: The apex is the conical, inferior, and pointed end of the heart, which is directed
downward, forward, and to the left, usually reaching the level of the fifth intercostal space.
Question 4
Which layer of the heart wall contains the epicardium?
,[Type here]
A) Myocardium.
B) Endocardium.
C) Pericardium.
D) Septum.
E) Chordae tendineae.
Correct Answer: C) Pericardium
Rationale: The epicardium is the outermost layer of the heart wall and is actually the
visceral layer of the serous pericardium. The pericardium itself is the double-walled sac
that surrounds and protects the heart.
Question 5
What anatomical structure directly surrounds the heart?
A) Pleura.
B) Peritoneum.
C) Pericardium.
D) Mediastinum.
E) Rib cage.
Correct Answer: C) Pericardium
Rationale: The pericardium is a double-layered sac that encloses the heart and the roots of
the great vessels. It consists of a fibrous outer layer and a serous inner layer (with visceral
and parietal components).
Question 6
The bicuspid valve is anatomically related to which other heart valve?
A) Tricuspid valve.
B) Aortic valve.
C) Pulmonic valve.
D) Mitral valve.
E) Both A and D.
Correct Answer: D) Mitral valve
Rationale: The bicuspid valve is another name for the mitral valve, located between the left
atrium and the left ventricle. Both terms refer to the same valve, which typically has two
cusps (leaflets). The tricuspid valve has three cusps.
Question 7
Which of the following structures contains oxygenated blood?
A) Right Atrium.
B) Pulmonary arteries.
C) Superior Vena Cava.
,[Type here]
D) Left Atrium, Pulmonary veins, Aorta.
E) Right Ventricle.
Correct Answer: D) Left Atrium, Pulmonary veins, Aorta
Rationale: The left atrium receives oxygenated blood from the pulmonary veins, and the
aorta distributes this oxygenated blood to the systemic circulation. All three listed
components in option D carry oxygenated blood.
Question 8
Which of the following structures contains deoxygenated blood?
A) Left Ventricle.
B) Pulmonary veins.
C) Aorta.
D) Superior Vena Cava, Right Atrium, Pulmonary Arteries.
E) Left Atrium.
Correct Answer: D) Superior Vena Cava, Right Atrium, Pulmonary Arteries
Rationale: The superior vena cava returns deoxygenated blood from the upper body to the
right atrium. The right atrium receives all systemic deoxygenated blood. The pulmonary
arteries carry deoxygenated blood from the right ventricle to the lungs.
Question 9
What specific vessels supply oxygenated blood to the heart muscle (myocardium)?
A) Pulmonary veins.
B) Aorta.
C) Coronary Arteries.
D) Vena Cava.
E) Pulmonary arteries.
Correct Answer: C) Coronary Arteries
Rationale: The coronary arteries branch off the aorta and deliver oxygen-rich blood directly
to the myocardium (heart muscle) itself, ensuring its continuous function.
Question 10
Which layer of the heart contains the contractile proteins actin, myosin, and troponin?
A) Endocardium.
B) Epicardium.
C) Myocardium.
D) Fibrous pericardium.
E) Visceral pericardium.
Correct Answer: C) Myocardium
Rationale: The myocardium is composed of cardiac muscle cells, which contain the
, [Type here]
contractile proteins actin and myosin, as well as regulatory proteins like troponin and
tropomyosin. These proteins are essential for muscle contraction.
Question 11
Which heart valves are open during atrial systole (atrial contraction)?
A) Aortic and Pulmonic valves.
B) Tricuspid and Mitral valves.
C) Mitral and Aortic valves.
D) Tricuspid and Pulmonic valves.
E) All four valves are closed.
Correct Answer: B) Tricuspid Mitral
Rationale: During atrial systole, the atria contract to push blood into the ventricles. To allow
this flow, the atrioventricular (AV) valves – the tricuspid valve (right) and the mitral
(bicuspid) valve (left) – must be open.
Question 12
Which of the following is true of blood leaving the tissues and traveling towards the right
atrium?
A) Oxygen rich, carbon dioxide poor.
B) Oxygen poor, carbon dioxide rich.
C) High in nutrients, low in waste.
D) Always fully oxygenated.
E) Under high pressure.
Correct Answer: B) Oxygen poor, carbon dioxide rich
Rationale: As blood circulates through systemic tissues, cells extract oxygen and nutrients,
and release carbon dioxide and metabolic waste products. Therefore, blood returning to the
right atrium via the vena cava is deoxygenated and rich in carbon dioxide.
Question 13
Which valve prevents the backflow of blood into the left ventricle when the left ventricle is in
diastole (relaxation)?
A) Mitral valve.
B) Tricuspid valve.
C) Pulmonic valve.
D) Aortic valve.
E) Both A and D.
Correct Answer: D) Aortic
Rationale: The aortic valve is a semilunar valve located between the left ventricle and the
aorta. During ventricular diastole, when the left ventricle relaxes and refills with blood, the
aortic valve closes to prevent backflow of blood from the aorta into the left ventricle.
Solutions
Question 1
The apex of the heart is anatomically located at the:
A) Right second intercostal space.
B) Left second intercostal space.
C) Fifth intercostal space, pointing down towards the left.
D) Third intercostal space, at the sternal border.
E) Base of the heart, near the great vessels.
Correct Answer: C) 5th intercostal space
Rationale: The apex of the heart is the pointed, inferior portion that typically extends
downwards and to the left, locating it in the fifth intercostal space, often just medial to the
midclavicular line.
Question 2
Which layer of the heart wall is primarily responsible for its pumping action?
A) Endocardium.
B) Epicardium.
C) Myocardium.
D) Pericardium.
E) Visceral pericardium.
Correct Answer: C) Myocardium
Rationale: The myocardium is the thick, muscular middle layer of the heart wall. It contains
cardiac muscle cells that contract to pump blood, making it the primary functional layer
for the heart's pumping action.
Question 3
What is the anatomical description of the apex of the heart?
A) The superior portion where the great vessels emerge.
B) The posterior surface, resting on the diaphragm.
C) The tip of the heart, pointing down towards the left 5th intercostal space.
D) The broad, flat superior portion.
E) The medial aspect, adjacent to the sternum.
Correct Answer: C) The tip of the heart, pointing down towards the left 5th intercostal
space.
Rationale: The apex is the conical, inferior, and pointed end of the heart, which is directed
downward, forward, and to the left, usually reaching the level of the fifth intercostal space.
Question 4
Which layer of the heart wall contains the epicardium?
,[Type here]
A) Myocardium.
B) Endocardium.
C) Pericardium.
D) Septum.
E) Chordae tendineae.
Correct Answer: C) Pericardium
Rationale: The epicardium is the outermost layer of the heart wall and is actually the
visceral layer of the serous pericardium. The pericardium itself is the double-walled sac
that surrounds and protects the heart.
Question 5
What anatomical structure directly surrounds the heart?
A) Pleura.
B) Peritoneum.
C) Pericardium.
D) Mediastinum.
E) Rib cage.
Correct Answer: C) Pericardium
Rationale: The pericardium is a double-layered sac that encloses the heart and the roots of
the great vessels. It consists of a fibrous outer layer and a serous inner layer (with visceral
and parietal components).
Question 6
The bicuspid valve is anatomically related to which other heart valve?
A) Tricuspid valve.
B) Aortic valve.
C) Pulmonic valve.
D) Mitral valve.
E) Both A and D.
Correct Answer: D) Mitral valve
Rationale: The bicuspid valve is another name for the mitral valve, located between the left
atrium and the left ventricle. Both terms refer to the same valve, which typically has two
cusps (leaflets). The tricuspid valve has three cusps.
Question 7
Which of the following structures contains oxygenated blood?
A) Right Atrium.
B) Pulmonary arteries.
C) Superior Vena Cava.
,[Type here]
D) Left Atrium, Pulmonary veins, Aorta.
E) Right Ventricle.
Correct Answer: D) Left Atrium, Pulmonary veins, Aorta
Rationale: The left atrium receives oxygenated blood from the pulmonary veins, and the
aorta distributes this oxygenated blood to the systemic circulation. All three listed
components in option D carry oxygenated blood.
Question 8
Which of the following structures contains deoxygenated blood?
A) Left Ventricle.
B) Pulmonary veins.
C) Aorta.
D) Superior Vena Cava, Right Atrium, Pulmonary Arteries.
E) Left Atrium.
Correct Answer: D) Superior Vena Cava, Right Atrium, Pulmonary Arteries
Rationale: The superior vena cava returns deoxygenated blood from the upper body to the
right atrium. The right atrium receives all systemic deoxygenated blood. The pulmonary
arteries carry deoxygenated blood from the right ventricle to the lungs.
Question 9
What specific vessels supply oxygenated blood to the heart muscle (myocardium)?
A) Pulmonary veins.
B) Aorta.
C) Coronary Arteries.
D) Vena Cava.
E) Pulmonary arteries.
Correct Answer: C) Coronary Arteries
Rationale: The coronary arteries branch off the aorta and deliver oxygen-rich blood directly
to the myocardium (heart muscle) itself, ensuring its continuous function.
Question 10
Which layer of the heart contains the contractile proteins actin, myosin, and troponin?
A) Endocardium.
B) Epicardium.
C) Myocardium.
D) Fibrous pericardium.
E) Visceral pericardium.
Correct Answer: C) Myocardium
Rationale: The myocardium is composed of cardiac muscle cells, which contain the
, [Type here]
contractile proteins actin and myosin, as well as regulatory proteins like troponin and
tropomyosin. These proteins are essential for muscle contraction.
Question 11
Which heart valves are open during atrial systole (atrial contraction)?
A) Aortic and Pulmonic valves.
B) Tricuspid and Mitral valves.
C) Mitral and Aortic valves.
D) Tricuspid and Pulmonic valves.
E) All four valves are closed.
Correct Answer: B) Tricuspid Mitral
Rationale: During atrial systole, the atria contract to push blood into the ventricles. To allow
this flow, the atrioventricular (AV) valves – the tricuspid valve (right) and the mitral
(bicuspid) valve (left) – must be open.
Question 12
Which of the following is true of blood leaving the tissues and traveling towards the right
atrium?
A) Oxygen rich, carbon dioxide poor.
B) Oxygen poor, carbon dioxide rich.
C) High in nutrients, low in waste.
D) Always fully oxygenated.
E) Under high pressure.
Correct Answer: B) Oxygen poor, carbon dioxide rich
Rationale: As blood circulates through systemic tissues, cells extract oxygen and nutrients,
and release carbon dioxide and metabolic waste products. Therefore, blood returning to the
right atrium via the vena cava is deoxygenated and rich in carbon dioxide.
Question 13
Which valve prevents the backflow of blood into the left ventricle when the left ventricle is in
diastole (relaxation)?
A) Mitral valve.
B) Tricuspid valve.
C) Pulmonic valve.
D) Aortic valve.
E) Both A and D.
Correct Answer: D) Aortic
Rationale: The aortic valve is a semilunar valve located between the left ventricle and the
aorta. During ventricular diastole, when the left ventricle relaxes and refills with blood, the
aortic valve closes to prevent backflow of blood from the aorta into the left ventricle.
