BIOS 255 EXAM 2 2026/2027 | Anatomy and Physiology III
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SECTION 1: CARDIOVASCULAR SYSTEM - ANATOMY (20 Questions)
Q1: A patient undergoes cardiac surgery requiring access to the heart chambers. The
surgeon must incise through the correct layers to reach the left ventricle. From
superficial to deep, which sequence of layers must be penetrated?
A. Endocardium, myocardium, epicardium, fibrous pericardium
B. Fibrous pericardium, parietal serous pericardium, pericardial cavity, visceral serous
pericardium (epicardium), myocardium, endocardium
C. Parietal pericardium, epicardium, endocardium, myocardium
D. Visceral pericardium, fibrous pericardium, myocardium, endocardium
B. Fibrous pericardium, parietal serous pericardium, pericardial cavity, visceral serous
pericardium (epicardium), myocardium, endocardium [CORRECT]
Correct Answer: B
Rationale: The heart is enclosed by the fibrous pericardium (outer tough layer), then the
parietal layer of the serous pericardium, followed by the pericardial cavity containing
lubricating serous fluid, then the visceral layer of the serous pericardium (epicardium),
the thick muscular myocardium, and finally the thin endocardium lining the chambers.
Option A reverses the order. Option C omits the fibrous pericardium and misplaces the
endocardium before the myocardium. Option D incorrectly places the visceral
pericardium superficial to the fibrous pericardium.
Q2: During a cardiac catheterization, a physician advances a catheter through the
femoral artery to access the coronary arteries. Which vessel does the catheter enter
immediately after passing through the aortic valve?
A. Pulmonary trunk
B. Left atrium
C. Left ventricle
D. Ascending aorta
,D. Ascending aorta [CORRECT]
Correct Answer: D
Rationale: The aortic valve lies between the left ventricle and the ascending aorta; after
passing through the aortic valve, the catheter enters the ascending aorta, from which
the right and left coronary arteries arise just above the valve at the aortic sinuses.
Option A is the vessel leaving the right ventricle via the pulmonary valve. Option B is
accessed through the mitral valve from the left ventricle. Option C is the chamber before
the aortic valve.
Q3: A patient presents with mitral valve regurgitation. During ventricular systole, blood
flows backward from the left ventricle into which chamber?
A. Right atrium
B. Right ventricle
C. Left atrium
D. Aorta
C. Left atrium [CORRECT]
Correct Answer: C
Rationale: The mitral (bicuspid) valve is located between the left atrium and left
ventricle; when it fails to close properly during systole, blood regurgitates from the
high-pressure left ventricle back into the left atrium. Option A describes tricuspid
regurgitation. Option B describes an abnormal ventricular septal defect. Option D would
occur with aortic insufficiency, not mitral regurgitation.
Q4: The coronary sinus drains deoxygenated blood from the heart muscle into which
chamber?
A. Left atrium
B. Right atrium
C. Right ventricle
D. Left ventricle
B. Right atrium [CORRECT]
Correct Answer: B
Rationale: The coronary sinus is the largest cardiac vein, located in the posterior
atrioventricular groove, and it drains approximately 70% of coronary venous blood from
the great cardiac vein, middle cardiac vein, and small cardiac vein into the right atrium
,near the opening of the inferior vena cava. Option A receives oxygenated blood from the
pulmonary veins. Options C and D are ventricular chambers that do not receive coronary
venous return directly.
Q5: A patient with recurrent pericarditis develops cardiac tamponade. Fluid
accumulates in which anatomical space to cause this life-threatening compression?
A. Between the fibrous pericardium and the parietal serous pericardium
B. Between the parietal serous pericardium and the visceral serous pericardium
(epicardium)
C. Within the myocardium
D. Between the endocardium and the myocardium
B. Between the parietal serous pericardium and the visceral serous pericardium
(epicardium) [CORRECT]
Correct Answer: B
Rationale: The pericardial cavity is the potential space between the parietal and visceral
layers of the serous pericardium; accumulation of blood or fluid in this space
compresses the heart, impairing ventricular filling and causing tamponade. Option A
describes the fibrous pericardial space, which is not a true cavity. Option C describes
intramyocardial hemorrhage. Option D describes an anatomically incorrect space.
Q6: The fibrous skeleton of the heart serves multiple important functions. Which
description best characterizes this structure?
A. It is composed entirely of cardiac muscle tissue that generates electrical impulses
B. It is a dense connective tissue framework that electrically insulates the atria from the
ventricles and provides attachment for heart valves and cardiac muscle
C. It is a fluid-filled cavity that lubricates the heart during contraction
D. It is the specialized conduction tissue connecting the SA and AV nodes
B. It is a dense connective tissue framework that electrically insulates the atria from the
ventricles and provides attachment for heart valves and cardiac muscle [CORRECT]
Correct Answer: B
Rationale: The fibrous skeleton of the heart consists of dense irregular connective
tissue rings surrounding the AV and semilunar valves, providing structural support for
valve attachment, preventing overstretching of valve orifices, and serving as an
electrical insulator between the atria and ventricles so that impulses must travel
, through the AV bundle. Option A incorrectly describes cardiac muscle. Option C
describes the pericardial cavity. Option D describes the internodal pathways, not the
fibrous skeleton.
Q7: A patient with Wolff-Parkinson-White syndrome has an accessory conduction
pathway bypassing the AV node. Normally, which structure is the only electrical
connection between the atria and ventricles?
A. Sinoatrial node
B. Atrioventricular bundle (Bundle of His)
C. Interatrial septum
D. Moderator band
B. Atrioventricular bundle (Bundle of His) [CORRECT]
Correct Answer: B
Rationale: The AV bundle (Bundle of His) is the only normal electrical pathway
connecting the atrial conduction system to the ventricular conduction system, as the
fibrous skeleton electrically insulates the atria from the ventricles; it emerges from the
AV node, penetrates the fibrous skeleton, and divides into right and left bundle
branches. Option A is the pacemaker of the heart located in the right atrium. Option C is
a structural wall, not a conduction pathway. Option D is a muscular band in the right
ventricle containing the right bundle branch.
Q8: The left coronary artery typically divides into which two major branches?
A. Right marginal artery and posterior interventricular artery
B. Anterior interventricular artery (LAD) and circumflex artery
C. Acute marginal artery and sinoatrial nodal artery
D. Posterior interventricular artery and right coronary artery
B. Anterior interventricular artery (LAD) and circumflex artery [CORRECT]
Correct Answer: B
Rationale: The left coronary artery arises from the left aortic sinus and typically
bifurcates into the anterior interventricular artery (left anterior descending, LAD)
supplying the anterior ventricular walls and interventricular septum, and the circumflex
artery supplying the left atrium and lateral left ventricular wall. Option A describes
Complete Guide | Verified Q&A | Chamberlain | Pass
Guaranteed - A+ Graded
SECTION 1: CARDIOVASCULAR SYSTEM - ANATOMY (20 Questions)
Q1: A patient undergoes cardiac surgery requiring access to the heart chambers. The
surgeon must incise through the correct layers to reach the left ventricle. From
superficial to deep, which sequence of layers must be penetrated?
A. Endocardium, myocardium, epicardium, fibrous pericardium
B. Fibrous pericardium, parietal serous pericardium, pericardial cavity, visceral serous
pericardium (epicardium), myocardium, endocardium
C. Parietal pericardium, epicardium, endocardium, myocardium
D. Visceral pericardium, fibrous pericardium, myocardium, endocardium
B. Fibrous pericardium, parietal serous pericardium, pericardial cavity, visceral serous
pericardium (epicardium), myocardium, endocardium [CORRECT]
Correct Answer: B
Rationale: The heart is enclosed by the fibrous pericardium (outer tough layer), then the
parietal layer of the serous pericardium, followed by the pericardial cavity containing
lubricating serous fluid, then the visceral layer of the serous pericardium (epicardium),
the thick muscular myocardium, and finally the thin endocardium lining the chambers.
Option A reverses the order. Option C omits the fibrous pericardium and misplaces the
endocardium before the myocardium. Option D incorrectly places the visceral
pericardium superficial to the fibrous pericardium.
Q2: During a cardiac catheterization, a physician advances a catheter through the
femoral artery to access the coronary arteries. Which vessel does the catheter enter
immediately after passing through the aortic valve?
A. Pulmonary trunk
B. Left atrium
C. Left ventricle
D. Ascending aorta
,D. Ascending aorta [CORRECT]
Correct Answer: D
Rationale: The aortic valve lies between the left ventricle and the ascending aorta; after
passing through the aortic valve, the catheter enters the ascending aorta, from which
the right and left coronary arteries arise just above the valve at the aortic sinuses.
Option A is the vessel leaving the right ventricle via the pulmonary valve. Option B is
accessed through the mitral valve from the left ventricle. Option C is the chamber before
the aortic valve.
Q3: A patient presents with mitral valve regurgitation. During ventricular systole, blood
flows backward from the left ventricle into which chamber?
A. Right atrium
B. Right ventricle
C. Left atrium
D. Aorta
C. Left atrium [CORRECT]
Correct Answer: C
Rationale: The mitral (bicuspid) valve is located between the left atrium and left
ventricle; when it fails to close properly during systole, blood regurgitates from the
high-pressure left ventricle back into the left atrium. Option A describes tricuspid
regurgitation. Option B describes an abnormal ventricular septal defect. Option D would
occur with aortic insufficiency, not mitral regurgitation.
Q4: The coronary sinus drains deoxygenated blood from the heart muscle into which
chamber?
A. Left atrium
B. Right atrium
C. Right ventricle
D. Left ventricle
B. Right atrium [CORRECT]
Correct Answer: B
Rationale: The coronary sinus is the largest cardiac vein, located in the posterior
atrioventricular groove, and it drains approximately 70% of coronary venous blood from
the great cardiac vein, middle cardiac vein, and small cardiac vein into the right atrium
,near the opening of the inferior vena cava. Option A receives oxygenated blood from the
pulmonary veins. Options C and D are ventricular chambers that do not receive coronary
venous return directly.
Q5: A patient with recurrent pericarditis develops cardiac tamponade. Fluid
accumulates in which anatomical space to cause this life-threatening compression?
A. Between the fibrous pericardium and the parietal serous pericardium
B. Between the parietal serous pericardium and the visceral serous pericardium
(epicardium)
C. Within the myocardium
D. Between the endocardium and the myocardium
B. Between the parietal serous pericardium and the visceral serous pericardium
(epicardium) [CORRECT]
Correct Answer: B
Rationale: The pericardial cavity is the potential space between the parietal and visceral
layers of the serous pericardium; accumulation of blood or fluid in this space
compresses the heart, impairing ventricular filling and causing tamponade. Option A
describes the fibrous pericardial space, which is not a true cavity. Option C describes
intramyocardial hemorrhage. Option D describes an anatomically incorrect space.
Q6: The fibrous skeleton of the heart serves multiple important functions. Which
description best characterizes this structure?
A. It is composed entirely of cardiac muscle tissue that generates electrical impulses
B. It is a dense connective tissue framework that electrically insulates the atria from the
ventricles and provides attachment for heart valves and cardiac muscle
C. It is a fluid-filled cavity that lubricates the heart during contraction
D. It is the specialized conduction tissue connecting the SA and AV nodes
B. It is a dense connective tissue framework that electrically insulates the atria from the
ventricles and provides attachment for heart valves and cardiac muscle [CORRECT]
Correct Answer: B
Rationale: The fibrous skeleton of the heart consists of dense irregular connective
tissue rings surrounding the AV and semilunar valves, providing structural support for
valve attachment, preventing overstretching of valve orifices, and serving as an
electrical insulator between the atria and ventricles so that impulses must travel
, through the AV bundle. Option A incorrectly describes cardiac muscle. Option C
describes the pericardial cavity. Option D describes the internodal pathways, not the
fibrous skeleton.
Q7: A patient with Wolff-Parkinson-White syndrome has an accessory conduction
pathway bypassing the AV node. Normally, which structure is the only electrical
connection between the atria and ventricles?
A. Sinoatrial node
B. Atrioventricular bundle (Bundle of His)
C. Interatrial septum
D. Moderator band
B. Atrioventricular bundle (Bundle of His) [CORRECT]
Correct Answer: B
Rationale: The AV bundle (Bundle of His) is the only normal electrical pathway
connecting the atrial conduction system to the ventricular conduction system, as the
fibrous skeleton electrically insulates the atria from the ventricles; it emerges from the
AV node, penetrates the fibrous skeleton, and divides into right and left bundle
branches. Option A is the pacemaker of the heart located in the right atrium. Option C is
a structural wall, not a conduction pathway. Option D is a muscular band in the right
ventricle containing the right bundle branch.
Q8: The left coronary artery typically divides into which two major branches?
A. Right marginal artery and posterior interventricular artery
B. Anterior interventricular artery (LAD) and circumflex artery
C. Acute marginal artery and sinoatrial nodal artery
D. Posterior interventricular artery and right coronary artery
B. Anterior interventricular artery (LAD) and circumflex artery [CORRECT]
Correct Answer: B
Rationale: The left coronary artery arises from the left aortic sinus and typically
bifurcates into the anterior interventricular artery (left anterior descending, LAD)
supplying the anterior ventricular walls and interventricular septum, and the circumflex
artery supplying the left atrium and lateral left ventricular wall. Option A describes
