BIOL 252 HUMAN ANATOMY AND PHYSIOLOGY II MODULE 1 EXAM COMPLETE SOLUTIONS DETAILED CORRECT ANSWERS WITH RATIONALES GRADE A+ GUARANTEED INSTANT DOWNLOAD | 100% PASS GUARANTEE

BIOL 252 HUMAN ANATOMY AND
PHYSIOLOGY II MODULE 1 EXAM
COMPLETE SOLUTIONS DETAILED
CORRECT ANSWERS WITH RATIONALES
GRADE A+ GUARANTEED INSTANT
DOWNLOAD | 100% PASS GUARANTEE




BIOL 252 Human Anatomy & Physiology II w/Lab |
Module 1 Exam
Question 1: A student is examining a histological slide of
cardiac muscle tissue under a microscope. Which specific
structural feature distinguishes cardiac muscle from skeletal
muscle? A) Multiple peripheral nuclei per cell B) Intercalated
discs connecting adjacent cells C) Lack of striations in the
cytoplasm D) Voluntary control by the somatic nervous system

Correct Answer: B) Intercalated discs connecting
adjacent cells
Rationale: Cardiac muscle cells are connected by
intercalated discs, which contain gap junctions for rapid
electrical conduction and desmosomes for mechanical
strength. Skeletal muscle has multiple peripheral nuclei and is
voluntary, while cardiac muscle has a single central nucleus
and is involuntary.
Question 2: During the cardiac cycle, the "lub" sound (S1) is
produced by the closure of which valves? A) Aortic and
pulmonary semilunar valves B) Mitral and tricuspid
atrioventricular valves C) Mitral and aortic valves D)
Tricuspid and pulmonary valves

,Correct Answer: B) Mitral and tricuspid
atrioventricular valves
Rationale: The first heart sound (S1) is caused by the
turbulence created when the atrioventricular (AV) valves
(mitral and tricuspid) close at the beginning of ventricular
systole to prevent backflow into the atria.
Question 3: A patient presents with edema in the lower
extremities and distended neck veins. The nurse suspects right-
sided heart failure. Which chamber of the heart is primarily
failing to pump blood effectively to the lungs? A) Left atrium B)
Left ventricle C) Right ventricle D) Right atrium

Correct Answer: C) Right ventricle
Rationale: The right ventricle pumps deoxygenated blood to
the lungs via the pulmonary artery. Failure of the right
ventricle causes blood to back up into the systemic venous
circulation, leading to jugular vein distension, hepatic
congestion, and peripheral edema.
Question 4: Which layer of the heart wall is composed of
cardiac muscle tissue and is responsible for the pumping action
of the heart? A) Endocardium B) Myocardium C) Epicardium
D) Pericardium

Correct Answer: B) Myocardium
Rationale: The myocardium is the thick middle layer of the
heart wall composed of cardiac muscle fibers. It is responsible
for the contractile force that pumps blood. The endocardium
lines the chambers, and the epicardium is the outer visceral
layer.
Question 5: In the intrinsic conduction system of the heart,
which structure acts as the primary pacemaker, initiating the

,electrical impulse? A) Atrioventricular (AV) node B) Bundle of
His C) Sinoatrial (SA) node D) Purkinje fibers

Correct Answer: C) Sinoatrial (SA) node
Rationale: The SA node, located in the right atrial wall, has
the highest inherent rate of depolarization (60-100 bpm) and
thus serves as the natural pacemaker of the heart, initiating
each heartbeat.
Question 6: A patient’s ECG shows a prolonged PR interval.
This finding indicates a delay in conduction through which part
of the heart? A) SA node B) AV node C) Bundle branches D)
Ventricular myocardium

Correct Answer: B) AV node
Rationale: The PR interval represents the time from the
onset of atrial depolarization to the onset of ventricular
depolarization. The majority of this delay occurs at the AV
node, which slows conduction to allow the atria to fully
contract and fill the ventricles before ventricular contraction
begins.
Question 7: Which blood vessel carries oxygenated blood from
the lungs to the left atrium? A) Pulmonary artery B) Superior
vena cava C) Pulmonary vein D) Aorta

Correct Answer: C) Pulmonary vein
Rationale: The pulmonary veins are the only veins in the
adult body that carry oxygenated blood. They return oxygen-
rich blood from the lungs to the left atrium. The pulmonary
arteries carry deoxygenated blood to the lungs.
Question 8: During ventricular systole, the pressure in the left
ventricle exceeds the pressure in the aorta. What happens to the
aortic valve? A) It closes to prevent backflow B) It opens to

, allow ejection of blood into the aorta C) It remains closed
until diastole D) It vibrates causing the second heart sound

Correct Answer: B) It opens to allow ejection of
blood into the aorta
Rationale: When left ventricular pressure exceeds aortic
pressure during systole, the aortic semilunar valve is forced
open, allowing blood to be ejected into the systemic
circulation. It closes when ventricular pressure falls below
aortic pressure at the end of systole.
Question 9: Which coronary artery supplies blood to the
anterior wall of the left ventricle and the interventricular
septum? A) Right coronary artery B) Circumflex artery C) Left
anterior descending (LAD) artery D) Posterior descending
artery

Correct Answer: C) Left anterior descending (LAD)
artery
Rationale: The LAD, a branch of the left coronary artery,
runs down the anterior interventricular sulcus. It supplies the
anterior walls of both ventricles and the anterior two-thirds of
the interventricular septum. Occlusion here is often called the
"widowmaker" due to the large amount of myocardium
affected.
Question 10: A patient has a heart rate of 45 beats per minute
and reports dizziness. The ECG shows regular P waves but no
relationship between P waves and QRS complexes. This
condition is known as: A) First-degree heart block B) Second-
degree heart block C) Third-degree (complete) heart
block D) Atrial fibrillation

Correct Answer: C) Third-degree (complete) heart
block