Physiology II w/Lab Exam Q&A | Portage Learning
1. The heart is located in the mediastinum, with its apex pointing toward the:
A) Left hip
B) Right shoulder
C) Center of the chest
D) Right hip
Correct Answer: A) Left hip
Rationale: The heart’s apex, formed by the left ventricle, is directed anteriorly,
inferiorly, and to the left, resting on the diaphragm near the fifth intercostal
space at the midclavicular line.
2. The outermost layer of the heart wall is the:
A) Myocardium
B) Epicardium
C) Endocardium
D) Pericardial cavity
Correct Answer: B) Epicardium
Rationale: The epicardium is the visceral layer of the serous pericardium. The
myocardium is the middle muscular layer; the endocardium lines the chambers.
The pericardial cavity is between the parietal and visceral layers.
,3. The thickest layer of the heart, responsible for contraction, is the:
A) Epicardium
B) Endocardium
C) Myocardium
D) Fibrous pericardium
Correct Answer: C) Myocardium
Rationale: The myocardium is composed of cardiac muscle tissue and is the bulk
of the heart wall, providing the force to eject blood. The epicardium is thin and
serous; endocardium is endothelium.
4. The right atrium receives deoxygenated blood from all of the following
EXCEPT:
A) Superior vena cava
B) Inferior vena cava
C) Coronary sinus
D) Pulmonary veins
Correct Answer: D) Pulmonary veins
Rationale: The pulmonary veins carry oxygenated blood from the lungs to the
left atrium. The vena cavae and coronary sinus return deoxygenated blood to
the right atrium.
, 5. Which valve prevents backflow from the right ventricle into the right atrium?
A) Tricuspid valve
B) Bicuspid valve
C) Pulmonary semilunar valve
D) Aortic semilunar valve
Correct Answer: A) Tricuspid valve
Rationale: The right atrioventricular (tricuspid) valve closes during ventricular
systole, preventing regurgitation into the right atrium. The bicuspid (mitral)
valve is on the left side.
6. The bicuspid (mitral) valve is located between the:
A) Right atrium and right ventricle
B) Right ventricle and pulmonary trunk
C) Left ventricle and aorta
D) Left atrium and left ventricle
Correct Answer: D) Left atrium and left ventricle
Rationale: The mitral valve is the left AV valve; it allows blood to flow from the
left atrium into the left ventricle and closes when the ventricle contracts,
preventing backflow.
7. The semilunar valves prevent backflow from the:
A) Atria into the ventricles