Verified Answers and In-Depth Clinical Rationales.
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Cardiac Anatomy, Physiology, and Risk Factors
**1. Which of the following are common risk factors for coronary artery disease
(CAD)?**
A. Hypertension
B. Smoking
C. Diabetes mellitus
D. Low LDL cholesterol
**Answer:** A, B, C
**Rationale:** Hypertension, smoking, and diabetes are well-established risk
factors that promote atherosclerosis. Low LDL cholesterol is actually protective
and reduces CAD risk.
**2. Where are Beta-1 receptors found?**
A. Heart and Kidneys
B. Lungs and Liver
C. Brain and Skeletal Muscle
D. Pancreas and Adrenal Glands
,**Answer:** A. Heart and Kidneys
**Rationale:** Beta-1 receptors are predominantly located in the heart and
kidneys. Stimulation of these receptors increases heart rate, contractility, and
conduction velocity (inotropy, chronotropy, dromotropy), and activates the renin-
angiotensin-aldosterone system in the kidneys.
**3. Stimulation of Beta-1 receptors results in an increase of what?**
A. Vasodilation and Bronchodilation
B. Inotropy, Chronotropy, Dromotropy
C. Peripheral Vasoconstriction only
D. Insulin and Glucagon secretion
**Answer:** B. Inotropy, Chronotropy, Dromotropy
**Rationale:** Beta-1 receptor stimulation in the heart increases the force of
contraction (inotropy), heart rate (chronotropy), and speed of electrical
conduction (dromotropy).
**4. Which node is located at the junction of the superior vena cava and the right
atrium, is typically supplied by the Right Coronary Artery, and fires at a rate of 60-
100 bpm?**
A. AV Node
B. SA Node
C. Bundle of His
D. Purkinje Fibers
,**Answer:** B. SA Node
**Rationale:** The sinoatrial (SA) node is the heart's primary pacemaker, located
in the right atrium near the superior vena cava. It is typically supplied by the right
coronary artery and has an intrinsic firing rate of 60-100 beats per minute.
**5. The innermost layer of the heart is called the:**
A. Epicardium
B. Myocardium
C. Endocardium
D. Pericardium
**Answer:** C. Endocardium
**Rationale:** The endocardium is the thin, smooth inner lining of the heart
chambers and valves.
**6. Cardiac Output (CO) is calculated by which formula?**
A. CO = BP x HR
B. CO = SV x HR
C. CO = SVR x HR
D. CO = EDV - ESV
**Answer:** B. CO = SV x HR
**Rationale:** Cardiac output is the volume of blood pumped by the heart per
minute and is calculated by multiplying stroke volume (SV) by heart rate (HR).
, **7. According to Starling's Law, when end-diastolic volume increases, what
happens to stroke volume?**
A. It decreases
B. It stays the same
C. It increases
D. It becomes unpredictable
**Answer:** C. It increases
**Rationale:** Starling's Law states that the greater the stretch of the cardiac
muscle fibers (due to increased end-diastolic volume), the more forceful the
contraction and the greater the stroke volume.
**8. Decrease in blood flow to the heart is called:**
A. Infarction
B. Ischemia
C. Necrosis
D. Occlusion
**Answer:** B. Ischemia
**Rationale:** Ischemia is a condition where there is a decrease in blood flow
and thus oxygen supply to a tissue, such as the heart muscle.
**9. The disorder in which calcium and cholesterol build up and form a plaque
inside the walls of the blood vessels is called:**
A. Atherosclerosis
B. Arteriosclerosis