BIOL 252 HUMAN ANATOMY &
PHYSIOLOGY II W/LAB | MODULE 2
2026/2027 WITH 100 QUESTIONS AND
EXPERT-VERIFIED CORRECT
ANSWERS | ALREADY GRADED A+ |
GUARANTEED SUCCESS
1. During ventricular systole, which event most directly prevents blood from
flowing backward into the atria?
A) Opening of the atrioventricular valves
B) Closure of the atrioventricular valves
C) Opening of the semilunar valves
D) Relaxation of the ventricles
Answer: B – The AV valves close when ventricular pressure rises above atrial
pressure during systole.
2. A patient has damage to the sinoatrial node. Which cardiac function would
be most directly affected?
A) Ventricular filling from the venae cavae
B) Production of plasma proteins
C) Initiation of the normal cardiac rhythm
D) Closure of the aortic valve
,Answer: C – The SA node is the heart's primary pacemaker and initiates the
normal rhythm.
3. An ECG shows a prolonged PR interval. Which process is most closely
represented by this interval?
A) Ventricular repolarization
B) Ventricular depolarization
C) Conduction from the atria through the AV node toward the ventricles
D) Atrial repolarization only
Answer: C – The PR interval represents time from atrial depolarization to
ventricular depolarization, including AV nodal conduction.
4. A decrease in venous return would most directly reduce which cardiac
variable?
(Answer: Stroke volume / preload – see rationale below)
5. Which structure separates the right and left sides of the heart and helps
prevent mixing of oxygenated and deoxygenated blood?
A) Myocardium
B) Pericardium
C) Interventricular and interatrial septa
D) Endocardium
Answer: C – Septa separate the chambers and prevent direct mixing between the
two sides.
6. Which valve is located between the right atrium and right ventricle?
A) Bicuspid valve
B) Aortic semilunar valve
C) Pulmonary semilunar valve
D) Tricuspid valve
Answer: D – The tricuspid valve has three cusps and controls blood flow between
the right atrium and right ventricle.
7. Which valve is located between the left atrium and left ventricle?
A) Tricuspid valve
B) Pulmonary valve
C) Bicuspid/mitral valve
D) Aortic valve
Answer: C – The bicuspid (mitral) valve separates the left atrium from the left
ventricle.
, 8. Which valve prevents blood from flowing backward from the left ventricle
into the left atrium during ventricular contraction?
A) Tricuspid valve
B) Pulmonary valve
C) Mitral valve
D) Aortic valve
Answer: C
9. Which chamber of the heart receives deoxygenated blood returning from
most of the systemic circulation?
A) Left atrium
B) Left ventricle
C) Right atrium
D) Right ventricle
Answer: C – The right atrium receives deoxygenated blood from the superior and
inferior vena cavae.
10. The heart is located in which cavity?
A) Abdominal cavity
B) Pericardial cavity within the mediastinum
C) Pleural cavity
D) Cranial cavity
Answer: B
11. Which component makes up the largest percentage of blood plasma?
A) Water
B) Albumin
C) Fibrinogen
D) Glucose
Answer: A – Plasma is approximately 92% water.
12. Mature erythrocytes are especially efficient at transporting oxygen
because they:
A) Contain lysosomes for gas storage
B) Lack nuclei and mitochondria
C) Synthesize antibodies
D) Produce clotting factors
Answer: B – Absence of nucleus and organelles maximizes space for hemoglobin.
PHYSIOLOGY II W/LAB | MODULE 2
2026/2027 WITH 100 QUESTIONS AND
EXPERT-VERIFIED CORRECT
ANSWERS | ALREADY GRADED A+ |
GUARANTEED SUCCESS
1. During ventricular systole, which event most directly prevents blood from
flowing backward into the atria?
A) Opening of the atrioventricular valves
B) Closure of the atrioventricular valves
C) Opening of the semilunar valves
D) Relaxation of the ventricles
Answer: B – The AV valves close when ventricular pressure rises above atrial
pressure during systole.
2. A patient has damage to the sinoatrial node. Which cardiac function would
be most directly affected?
A) Ventricular filling from the venae cavae
B) Production of plasma proteins
C) Initiation of the normal cardiac rhythm
D) Closure of the aortic valve
,Answer: C – The SA node is the heart's primary pacemaker and initiates the
normal rhythm.
3. An ECG shows a prolonged PR interval. Which process is most closely
represented by this interval?
A) Ventricular repolarization
B) Ventricular depolarization
C) Conduction from the atria through the AV node toward the ventricles
D) Atrial repolarization only
Answer: C – The PR interval represents time from atrial depolarization to
ventricular depolarization, including AV nodal conduction.
4. A decrease in venous return would most directly reduce which cardiac
variable?
(Answer: Stroke volume / preload – see rationale below)
5. Which structure separates the right and left sides of the heart and helps
prevent mixing of oxygenated and deoxygenated blood?
A) Myocardium
B) Pericardium
C) Interventricular and interatrial septa
D) Endocardium
Answer: C – Septa separate the chambers and prevent direct mixing between the
two sides.
6. Which valve is located between the right atrium and right ventricle?
A) Bicuspid valve
B) Aortic semilunar valve
C) Pulmonary semilunar valve
D) Tricuspid valve
Answer: D – The tricuspid valve has three cusps and controls blood flow between
the right atrium and right ventricle.
7. Which valve is located between the left atrium and left ventricle?
A) Tricuspid valve
B) Pulmonary valve
C) Bicuspid/mitral valve
D) Aortic valve
Answer: C – The bicuspid (mitral) valve separates the left atrium from the left
ventricle.
, 8. Which valve prevents blood from flowing backward from the left ventricle
into the left atrium during ventricular contraction?
A) Tricuspid valve
B) Pulmonary valve
C) Mitral valve
D) Aortic valve
Answer: C
9. Which chamber of the heart receives deoxygenated blood returning from
most of the systemic circulation?
A) Left atrium
B) Left ventricle
C) Right atrium
D) Right ventricle
Answer: C – The right atrium receives deoxygenated blood from the superior and
inferior vena cavae.
10. The heart is located in which cavity?
A) Abdominal cavity
B) Pericardial cavity within the mediastinum
C) Pleural cavity
D) Cranial cavity
Answer: B
11. Which component makes up the largest percentage of blood plasma?
A) Water
B) Albumin
C) Fibrinogen
D) Glucose
Answer: A – Plasma is approximately 92% water.
12. Mature erythrocytes are especially efficient at transporting oxygen
because they:
A) Contain lysosomes for gas storage
B) Lack nuclei and mitochondria
C) Synthesize antibodies
D) Produce clotting factors
Answer: B – Absence of nucleus and organelles maximizes space for hemoglobin.
