BIOS 255 / BIOS255 ANATOMY AND PHYSIOLOGY III
ACTUAL EXAM 2026/2027 | COMPLETE EXAM-STYLE
QUESTIONS | 100% VERIFIED – DETAILED RATIONALES –
PASS GUARANTEED – A+ GRADED
Below are **50 questions and answers** modeled on the BIOS 255 / BIOS255 (Anatomy & Physiology III
with Lab) cumulative final exams from Chamberlain College of Nursing. Each answer includes a **clinical
rationale** to help you understand the "why" behind the correct choice.
*Note: While these are based on actual exam patterns from 2024-2027, always verify specific details
with your course materials and instructors.*
---
### Questions 1-20: Cardiovascular System (Heart & Hemodynamics)
**1. The primary function of the circulatory system is:**
A. Production of hormones
B. Absorption of nutrients
C. Transport of nutrients, gases, and wastes
D. Regulation of body temperature only
**Answer: C. Transport of nutrients, gases, and wastes**
*Rationale*: The circulatory system is the body's delivery network. It moves oxygen (O2) from the
lungs to tissues, carbon dioxide (CO2) from tissues to lungs, nutrients from the digestive tract to cells,
and metabolic wastes to the kidneys for excretion.
**2. Which chamber of the heart receives oxygenated blood from the lungs?**
A. Left atrium
B. Right atrium
C. Left ventricle
,D. Right ventricle
**Answer: A. Left atrium**
*Rationale*: Oxygenated blood returns from the lungs via the **pulmonary veins** and enters the
left atrium. Note: This is the only time veins carry oxygen-rich blood.
**3. Which chamber pumps oxygenated blood to the body?**
A. Left ventricle
B. Right ventricle
C. Left atrium
D. Right atrium
**Answer: A. Left ventricle**
*Rationale*: The **left ventricle** has the thickest myocardium because it must generate high
pressure to push blood through the systemic circulation via the aorta. The right ventricle only pumps to
the nearby lungs.
**4. Which valve prevents backflow from the left ventricle to the left atrium?**
A. Mitral (bicuspid) valve
B. Tricuspid valve
C. Aortic valve
D. Pulmonary valve
**Answer: A. Mitral (bicuspid) valve**
*Rationale*: The **mitral valve** (two cusps) sits between the left atrium and left ventricle. It
closes during ventricular systole (contraction) to ensure blood goes up into the aorta, not back into the
lung veins.
**5. The valve between the right atrium and right ventricle is the:**
A. Mitral valve
, B. Tricuspid valve
C. Aortic valve
D. Pulmonary valve
**Answer: B. Tricuspid valve**
*Rationale*: The right atrioventricular (AV) valve has three cusps, hence the name "tricuspid." It
prevents backflow into the right atrium when the right ventricle contracts.
**6. The "Lub" (first heart sound) corresponds to:**
A. Closure of semilunar valves
B. Closure of AV valves
C. Opening of AV valves
D. Atrial contraction
**Answer: B. Closure of AV valves**
*Rationale*: "Lub" occurs at the beginning of **ventricular systole**. The high pressure in the
ventricles forces the tricuspid and mitral valves to snap shut, creating the sound.
**7. The pacemaker of the heart is the:**
A. Atrioventricular (AV) node
B. Purkinje fibers
C. Sinoatrial (SA) node
D. Bundle of His
**Answer: C. Sinoatrial (SA) node**
*Rationale*: Located in the right atrial wall, the **SA node** depolarizes spontaneously 60-100
times per minute, setting the normal heart rhythm. It is the primary pacemaker.
**8. On an ECG, the P wave represents:**
A. Ventricular depolarization
ACTUAL EXAM 2026/2027 | COMPLETE EXAM-STYLE
QUESTIONS | 100% VERIFIED – DETAILED RATIONALES –
PASS GUARANTEED – A+ GRADED
Below are **50 questions and answers** modeled on the BIOS 255 / BIOS255 (Anatomy & Physiology III
with Lab) cumulative final exams from Chamberlain College of Nursing. Each answer includes a **clinical
rationale** to help you understand the "why" behind the correct choice.
*Note: While these are based on actual exam patterns from 2024-2027, always verify specific details
with your course materials and instructors.*
---
### Questions 1-20: Cardiovascular System (Heart & Hemodynamics)
**1. The primary function of the circulatory system is:**
A. Production of hormones
B. Absorption of nutrients
C. Transport of nutrients, gases, and wastes
D. Regulation of body temperature only
**Answer: C. Transport of nutrients, gases, and wastes**
*Rationale*: The circulatory system is the body's delivery network. It moves oxygen (O2) from the
lungs to tissues, carbon dioxide (CO2) from tissues to lungs, nutrients from the digestive tract to cells,
and metabolic wastes to the kidneys for excretion.
**2. Which chamber of the heart receives oxygenated blood from the lungs?**
A. Left atrium
B. Right atrium
C. Left ventricle
,D. Right ventricle
**Answer: A. Left atrium**
*Rationale*: Oxygenated blood returns from the lungs via the **pulmonary veins** and enters the
left atrium. Note: This is the only time veins carry oxygen-rich blood.
**3. Which chamber pumps oxygenated blood to the body?**
A. Left ventricle
B. Right ventricle
C. Left atrium
D. Right atrium
**Answer: A. Left ventricle**
*Rationale*: The **left ventricle** has the thickest myocardium because it must generate high
pressure to push blood through the systemic circulation via the aorta. The right ventricle only pumps to
the nearby lungs.
**4. Which valve prevents backflow from the left ventricle to the left atrium?**
A. Mitral (bicuspid) valve
B. Tricuspid valve
C. Aortic valve
D. Pulmonary valve
**Answer: A. Mitral (bicuspid) valve**
*Rationale*: The **mitral valve** (two cusps) sits between the left atrium and left ventricle. It
closes during ventricular systole (contraction) to ensure blood goes up into the aorta, not back into the
lung veins.
**5. The valve between the right atrium and right ventricle is the:**
A. Mitral valve
, B. Tricuspid valve
C. Aortic valve
D. Pulmonary valve
**Answer: B. Tricuspid valve**
*Rationale*: The right atrioventricular (AV) valve has three cusps, hence the name "tricuspid." It
prevents backflow into the right atrium when the right ventricle contracts.
**6. The "Lub" (first heart sound) corresponds to:**
A. Closure of semilunar valves
B. Closure of AV valves
C. Opening of AV valves
D. Atrial contraction
**Answer: B. Closure of AV valves**
*Rationale*: "Lub" occurs at the beginning of **ventricular systole**. The high pressure in the
ventricles forces the tricuspid and mitral valves to snap shut, creating the sound.
**7. The pacemaker of the heart is the:**
A. Atrioventricular (AV) node
B. Purkinje fibers
C. Sinoatrial (SA) node
D. Bundle of His
**Answer: C. Sinoatrial (SA) node**
*Rationale*: Located in the right atrial wall, the **SA node** depolarizes spontaneously 60-100
times per minute, setting the normal heart rhythm. It is the primary pacemaker.
**8. On an ECG, the P wave represents:**
A. Ventricular depolarization
