San Francisco State University – BIO 240 Exam 3 Actual– Full 100-Question Study Guide Comprehensive Questions with Answers and Explanations| PDF

San Francisco State University – BIO 240 Exam 3 Actual–
Full 100-Question Study Guide Comprehensive Questions
with Answers and Explanations| PDF



Topics Covered: Cardiovascular, Respiratory, Renal, Digestive, Endocrine, Nervous Systems,
and Integrative Physiology

Cardiovascular Physiology

Q1. The primary pacemaker of the heart is:

 A) Sinoatrial (SA) node
 B) Atrioventricular (AV) node
 C) Purkinje fibers
 D) Bundle of His
Explanation: The SA node initiates the heartbeat.

Q2. During ventricular systole, which valves are open?

 A) AV valves
 B) Semilunar valves (aortic and pulmonary)
 C) All valves
 D) Only mitral valve
Explanation: Semilunar valves allow blood to exit the ventricles.

Q3. Stroke volume is influenced by:

 A) Heart rate only
 B) Blood pressure only
 C) Preload, afterload, and contractility
 D) Venous return only
Explanation: All three factors determine the amount of blood
ejected.

,Q4. The Frank-Starling law describes:

 A) Greater ventricular filling increases stroke volume
 B) Heart rate directly proportional to BP
 C) BP independent of stroke volume
 D) Cardiac output is fixed
Explanation: Stretch of cardiac muscle fibers enhances
contraction.

Q5. Baroreceptors detect changes in:

 A) Blood pressure
 B) Oxygen levels
 C) CO₂ levels
 D) Sodium concentration
Explanation: Located in carotid sinus and aortic arch to maintain
BP.

Q6. Sympathetic stimulation affects the heart by:

 A) Increasing heart rate and contractility
 B) Decreasing heart rate
 C) No effect
 D) Only affects AV conduction
Explanation: Norepinephrine binds β1 receptors to increase
cardiac output.

Q7. The mean arterial pressure (MAP) can be approximated as:

 A) Diastolic pressure + 1/3 pulse pressure
 B) Systolic + diastolic / 2
 C) Heart rate × stroke volume
 D) Pulse pressure only
Explanation: Reflects the average blood pressure during cardiac
cycle.

, Q8. Which ion primarily mediates the depolarization phase of cardiac
action potentials?

 A) Sodium (Na⁺)
 B) Potassium (K⁺)
 C) Calcium (Ca²⁺)
 D) Chloride (Cl⁻)
Explanation: Rapid influx of Na⁺ initiates the upstroke.

Q9. Capillaries are the main site of:

 A) Exchange of gases, nutrients, and waste
 B) Pressure generation
 C) Blood storage
 D) Oxygen transport only
Explanation: Thin walls allow diffusion between blood and
tissues.

Q10. Venous return is aided by:

 A) Skeletal muscle pump and respiratory pump
 B) Only gravity
 C) Arterial pressure alone
 D) None of the above
Explanation: Muscle contractions and thoracic pressure changes
move blood back to the heart.



Respiratory Physiology

Q11. The diaphragm contracts during:

 A) Inspiration
 B) Expiration
 C) Forced expiration only