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BIOS 255 / BIOS255 Anatomy and Physiology III
Actual Exam 2026/2027 | Complete Exam-Style
Questions | 100% Verified – Detailed Rationales –
Pass Guaranteed – A+ Graded
TABLE OF CONTENTS
Section 1 | Cardiovascular System: Heart and Vessels | Q1 – Q15
Section 2 | Cardiovascular System: Blood and Hemodynamics | Q16 – Q30
Section 3 | Lymphatic and Immune Systems | Q31 – Q45
Section 4 | Respiratory System | Q46 – Q60
Section 5 | Renal and Urinary Systems | Q61 – Q75
SECTION 1: CARDIOVASCULAR SYSTEM — HEART AND VESSELS
Question 1 of 75
A 67-year-old patient arrives in the emergency department complaining of crushing chest pain
radiating to the left arm. The physician suspects myocardial ischemia affecting the anterior wall
of the left ventricle. The nurse understands that blood supply to this region is provided primarily
by which coronary vessel?
A. The right coronary artery, which typically supplies the right atrium and ventricle
B. The circumflex artery, which courses along the coronary sulcus to supply the left atrium and
posterior left ventricle
C. The left anterior descending artery, which descends along the anterior interventricular sulcus
to perfuse the anterior left ventricle and interventricular septum ✓ CORRECT
D. The posterior interventricular artery, which arises from the right coronary artery in most
individuals and supplies the posterior ventricular walls
Correct Answer: C
Rationale: The left anterior descending artery branches from the left coronary artery and travels
within the anterior interventricular sulcus, delivering oxygenated blood to the anterior wall of the
left ventricle and the anterior two-thirds of the interventricular septum. Many students
mistakenly select the circumflex artery because it also arises from the left coronary artery, but the
circumflex primarily serves the left atrium and lateral or posterior left ventricle rather than the
,2
anterior wall. Clinically, occlusion of the left anterior descending artery produces anterior wall
myocardial infarctions that often present with the classic crushing substernal pain described in
this scenario.
Question 2 of 75
A 54-year-old male with a history of hypertension presents for a routine physical examination.
During cardiac auscultation, the nurse places the stethoscope at the left fifth intercostal space
near the midclavicular line and hears the first heart sound, which corresponds to which
physiological event?
A. Closure of the semilunar valves marking the onset of diastole
B. Closure of the atrioventricular valves indicating the beginning of ventricular systole ✓
CORRECT
C. Opening of the mitral valve allowing passive ventricular filling
D. Vibration of the ventricular walls during rapid ejection of blood
Correct Answer: B
Rationale: The first heart sound, often described as "lub," is produced by the closure of the
tricuspid and mitral valves at the onset of ventricular systole when intraventricular pressure
exceeds atrial pressure. Students frequently confuse this with the second heart sound, which
arises from semilunar valve closure and signals the beginning of diastole rather than systole.
Accurate auscultation at the apex of the heart allows nurses to assess mitral valve function and
detect abnormalities such as regurgitation or stenosis.
Question 3 of 75
During a telemetry rotation, a nursing student observes the electrocardiogram of a 72-year-old
patient and notes a small, rounded upward deflection that immediately precedes each QRS
complex. The student correctly identifies this waveform as representing which electrical event?
A. Atrial depolarization initiated by the sinoatrial node ✓ CORRECT
B. Ventricular repolarization occurring during the resting phase of the cardiac cycle
C. Atrial contraction forcing blood through the open atrioventricular valves
D. Ventricular depolarization spreading through the bundle of His and Purkinje fibers
Correct Answer: A
Rationale: The P wave on a standard electrocardiogram represents the wave of depolarization
that originates at the sinoatrial node and spreads across the atrial myocardium, triggering atrial
contraction. A common misconception is that the P wave reflects atrial contraction itself rather
,3
than the electrical depolarization that precedes mechanical contraction by a brief interval. Nurses
monitoring telemetry must recognize that absent or irregular P waves may indicate sinoatrial
node dysfunction or atrial arrhythmias requiring immediate intervention.
Question 4 of 75
A 45-year-old marathon runner undergoes cardiovascular assessment and is found to have a
resting heart rate of 48 beats per minute. The nurse explains to the patient that this bradycardia is
likely a beneficial adaptation resulting from which physiological change?
A. Decreased parasympathetic tone allowing greater sympathetic influence on the sinoatrial node
B. Reduced stroke volume requiring fewer cardiac cycles to maintain adequate perfusion
C. Increased peripheral vascular resistance elevating systemic blood pressure at rest
D. Enhanced vagal tone and greater ventricular filling time increasing stroke volume ✓
CORRECT
Correct Answer: D
Rationale: Well-conditioned athletes often develop physiological bradycardia due to increased
parasympathetic vagal tone and greater ventricular compliance, which allows more complete
diastolic filling and produces a higher stroke volume with each contraction. Many students
incorrectly assume that a low heart rate indicates poor cardiac output, but in trained individuals
the heart pumps more blood per beat and therefore requires fewer beats per minute to maintain
the same cardiac output. Nurses should distinguish this benign adaptation from pathological
bradycardia caused by sinus node disease or medication toxicity.
Question 5 of 75
A 58-year-old patient with peripheral arterial disease reports pain in the calves during walking
that subsides with rest. During discharge teaching, the nurse explains that this claudication
results from insufficient blood flow through vessels that normally carry oxygen-rich blood away
from the heart. Which structural layer of these vessels is most responsible for maintaining
vascular tone and blood pressure?
A. The tunica intima, composed of simple squamous endothelium that reduces friction
B. The tunica externa, composed of collagen fibers that anchor vessels to surrounding tissues
C. The tunica media, composed of smooth muscle and elastic fibers that regulate vessel diameter
✓ CORRECT
D. The tunica adventitia, composed of loose connective tissue that houses the vasa vasorum
Correct Answer: C
, 4
Rationale: The tunica media contains circumferentially arranged smooth muscle fibers and
variable amounts of elastic tissue that enable vessels to constrict or dilate, thereby regulating
vascular resistance and systemic blood pressure. Students sometimes select the tunica intima
because it forms the blood-contacting surface, but this endothelial layer primarily prevents
thrombosis and controls permeability rather than generating contractile force. Understanding
tunica media function helps nurses anticipate how vasodilators such as nitrates reduce afterload
by relaxing this smooth muscle layer in arterial walls.
Question 6 of 75
A 39-year-old patient in the intensive care unit has an arterial line placed for continuous blood
pressure monitoring. The waveform shows a peak systolic pressure of 140 mmHg and a diastolic
pressure of 85 mmHg. The nurse calculates the mean arterial pressure, recognizing that this value
represents the average pressure driving blood into the tissues during the entire cardiac cycle.
What is the patient's approximate mean arterial pressure?
A. 100 mmHg, calculated by adding systolic and diastolic pressures and dividing by two
B. 103 mmHg, calculated using the formula diastolic pressure plus one-third of the pulse
pressure ✓ CORRECT
C. 112 mmHg, calculated by averaging systolic pressure and twice the diastolic pressure
D. 95 mmHg, calculated by subtracting diastolic pressure from systolic pressure
Correct Answer: B
Rationale: Mean arterial pressure is approximated by adding the diastolic pressure to one-third of
the pulse pressure, where pulse pressure equals systolic minus diastolic pressure; for this patient,
85 plus one-third of 55 yields approximately 103 mmHg. Students often mistakenly average
systolic and diastolic pressures, but this ignores the fact that diastole occupies roughly two-thirds
of the cardiac cycle and therefore contributes more to tissue perfusion. Accurate MAP
calculation guides nurses in assessing organ perfusion and titrating vasoactive medications in
critically ill patients.
Question 7 of 75
During a cardiac catheterization educational session, a 62-year-old patient asks why the aortic
semilunar valve prevents backflow into the left ventricle. The nurse explains that this valve
closes when pressure in which chamber exceeds pressure in the aorta?
A. The left ventricle during ventricular relaxation when aortic pressure surpasses ventricular
pressure ✓ CORRECT
B. The left atrium during atrial contraction when it exceeds pulmonary venous pressure
BIOS 255 / BIOS255 Anatomy and Physiology III
Actual Exam 2026/2027 | Complete Exam-Style
Questions | 100% Verified – Detailed Rationales –
Pass Guaranteed – A+ Graded
TABLE OF CONTENTS
Section 1 | Cardiovascular System: Heart and Vessels | Q1 – Q15
Section 2 | Cardiovascular System: Blood and Hemodynamics | Q16 – Q30
Section 3 | Lymphatic and Immune Systems | Q31 – Q45
Section 4 | Respiratory System | Q46 – Q60
Section 5 | Renal and Urinary Systems | Q61 – Q75
SECTION 1: CARDIOVASCULAR SYSTEM — HEART AND VESSELS
Question 1 of 75
A 67-year-old patient arrives in the emergency department complaining of crushing chest pain
radiating to the left arm. The physician suspects myocardial ischemia affecting the anterior wall
of the left ventricle. The nurse understands that blood supply to this region is provided primarily
by which coronary vessel?
A. The right coronary artery, which typically supplies the right atrium and ventricle
B. The circumflex artery, which courses along the coronary sulcus to supply the left atrium and
posterior left ventricle
C. The left anterior descending artery, which descends along the anterior interventricular sulcus
to perfuse the anterior left ventricle and interventricular septum ✓ CORRECT
D. The posterior interventricular artery, which arises from the right coronary artery in most
individuals and supplies the posterior ventricular walls
Correct Answer: C
Rationale: The left anterior descending artery branches from the left coronary artery and travels
within the anterior interventricular sulcus, delivering oxygenated blood to the anterior wall of the
left ventricle and the anterior two-thirds of the interventricular septum. Many students
mistakenly select the circumflex artery because it also arises from the left coronary artery, but the
circumflex primarily serves the left atrium and lateral or posterior left ventricle rather than the
,2
anterior wall. Clinically, occlusion of the left anterior descending artery produces anterior wall
myocardial infarctions that often present with the classic crushing substernal pain described in
this scenario.
Question 2 of 75
A 54-year-old male with a history of hypertension presents for a routine physical examination.
During cardiac auscultation, the nurse places the stethoscope at the left fifth intercostal space
near the midclavicular line and hears the first heart sound, which corresponds to which
physiological event?
A. Closure of the semilunar valves marking the onset of diastole
B. Closure of the atrioventricular valves indicating the beginning of ventricular systole ✓
CORRECT
C. Opening of the mitral valve allowing passive ventricular filling
D. Vibration of the ventricular walls during rapid ejection of blood
Correct Answer: B
Rationale: The first heart sound, often described as "lub," is produced by the closure of the
tricuspid and mitral valves at the onset of ventricular systole when intraventricular pressure
exceeds atrial pressure. Students frequently confuse this with the second heart sound, which
arises from semilunar valve closure and signals the beginning of diastole rather than systole.
Accurate auscultation at the apex of the heart allows nurses to assess mitral valve function and
detect abnormalities such as regurgitation or stenosis.
Question 3 of 75
During a telemetry rotation, a nursing student observes the electrocardiogram of a 72-year-old
patient and notes a small, rounded upward deflection that immediately precedes each QRS
complex. The student correctly identifies this waveform as representing which electrical event?
A. Atrial depolarization initiated by the sinoatrial node ✓ CORRECT
B. Ventricular repolarization occurring during the resting phase of the cardiac cycle
C. Atrial contraction forcing blood through the open atrioventricular valves
D. Ventricular depolarization spreading through the bundle of His and Purkinje fibers
Correct Answer: A
Rationale: The P wave on a standard electrocardiogram represents the wave of depolarization
that originates at the sinoatrial node and spreads across the atrial myocardium, triggering atrial
contraction. A common misconception is that the P wave reflects atrial contraction itself rather
,3
than the electrical depolarization that precedes mechanical contraction by a brief interval. Nurses
monitoring telemetry must recognize that absent or irregular P waves may indicate sinoatrial
node dysfunction or atrial arrhythmias requiring immediate intervention.
Question 4 of 75
A 45-year-old marathon runner undergoes cardiovascular assessment and is found to have a
resting heart rate of 48 beats per minute. The nurse explains to the patient that this bradycardia is
likely a beneficial adaptation resulting from which physiological change?
A. Decreased parasympathetic tone allowing greater sympathetic influence on the sinoatrial node
B. Reduced stroke volume requiring fewer cardiac cycles to maintain adequate perfusion
C. Increased peripheral vascular resistance elevating systemic blood pressure at rest
D. Enhanced vagal tone and greater ventricular filling time increasing stroke volume ✓
CORRECT
Correct Answer: D
Rationale: Well-conditioned athletes often develop physiological bradycardia due to increased
parasympathetic vagal tone and greater ventricular compliance, which allows more complete
diastolic filling and produces a higher stroke volume with each contraction. Many students
incorrectly assume that a low heart rate indicates poor cardiac output, but in trained individuals
the heart pumps more blood per beat and therefore requires fewer beats per minute to maintain
the same cardiac output. Nurses should distinguish this benign adaptation from pathological
bradycardia caused by sinus node disease or medication toxicity.
Question 5 of 75
A 58-year-old patient with peripheral arterial disease reports pain in the calves during walking
that subsides with rest. During discharge teaching, the nurse explains that this claudication
results from insufficient blood flow through vessels that normally carry oxygen-rich blood away
from the heart. Which structural layer of these vessels is most responsible for maintaining
vascular tone and blood pressure?
A. The tunica intima, composed of simple squamous endothelium that reduces friction
B. The tunica externa, composed of collagen fibers that anchor vessels to surrounding tissues
C. The tunica media, composed of smooth muscle and elastic fibers that regulate vessel diameter
✓ CORRECT
D. The tunica adventitia, composed of loose connective tissue that houses the vasa vasorum
Correct Answer: C
, 4
Rationale: The tunica media contains circumferentially arranged smooth muscle fibers and
variable amounts of elastic tissue that enable vessels to constrict or dilate, thereby regulating
vascular resistance and systemic blood pressure. Students sometimes select the tunica intima
because it forms the blood-contacting surface, but this endothelial layer primarily prevents
thrombosis and controls permeability rather than generating contractile force. Understanding
tunica media function helps nurses anticipate how vasodilators such as nitrates reduce afterload
by relaxing this smooth muscle layer in arterial walls.
Question 6 of 75
A 39-year-old patient in the intensive care unit has an arterial line placed for continuous blood
pressure monitoring. The waveform shows a peak systolic pressure of 140 mmHg and a diastolic
pressure of 85 mmHg. The nurse calculates the mean arterial pressure, recognizing that this value
represents the average pressure driving blood into the tissues during the entire cardiac cycle.
What is the patient's approximate mean arterial pressure?
A. 100 mmHg, calculated by adding systolic and diastolic pressures and dividing by two
B. 103 mmHg, calculated using the formula diastolic pressure plus one-third of the pulse
pressure ✓ CORRECT
C. 112 mmHg, calculated by averaging systolic pressure and twice the diastolic pressure
D. 95 mmHg, calculated by subtracting diastolic pressure from systolic pressure
Correct Answer: B
Rationale: Mean arterial pressure is approximated by adding the diastolic pressure to one-third of
the pulse pressure, where pulse pressure equals systolic minus diastolic pressure; for this patient,
85 plus one-third of 55 yields approximately 103 mmHg. Students often mistakenly average
systolic and diastolic pressures, but this ignores the fact that diastole occupies roughly two-thirds
of the cardiac cycle and therefore contributes more to tissue perfusion. Accurate MAP
calculation guides nurses in assessing organ perfusion and titrating vasoactive medications in
critically ill patients.
Question 7 of 75
During a cardiac catheterization educational session, a 62-year-old patient asks why the aortic
semilunar valve prevents backflow into the left ventricle. The nurse explains that this valve
closes when pressure in which chamber exceeds pressure in the aorta?
A. The left ventricle during ventricular relaxation when aortic pressure surpasses ventricular
pressure ✓ CORRECT
B. The left atrium during atrial contraction when it exceeds pulmonary venous pressure
