What is a condition where the heart's ability to pump blood is reduced because the heart muscle is enlarged, thickened, or stiffened?
- A. Cardiomyopathy
- B. Endocarditis
- C. Myocarditis
- D. Aortic stenosis
Correct Answer: A
Rationale: The correct answer is A: Cardiomyopathy. Cardiomyopathy refers to a condition where the heart muscle is enlarged, thickened, or stiffened, leading to a reduced ability to pump blood effectively. This condition directly relates to the heart's structural changes, impacting its pumping function. Endocarditis (B) is an infection of the heart's inner lining, not directly related to heart muscle changes. Myocarditis (C) is inflammation of the heart muscle but does not necessarily involve structural changes leading to reduced pumping ability. Aortic stenosis (D) is a condition where the heart's aortic valve is narrowed, impeding blood flow, but it does not specifically refer to the heart muscle changes seen in cardiomyopathy.
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Which condition is characterized by the lungs becoming scarred and stiff, leading to difficulty breathing and inadequate oxygen intake into the bloodstream?
- A. Pulmonary fibrosis
- B. Cystic fibrosis
- C. COPD
- D. Tuberculosis
Correct Answer: A
Rationale: Pulmonary fibrosis is characterized by scarring and stiffening of the lungs, impairing their ability to expand and contract properly for breathing. This leads to difficulty breathing and inadequate oxygen intake into the bloodstream. In contrast, cystic fibrosis primarily affects the respiratory and digestive systems, COPD is a progressive lung disease primarily caused by smoking, and tuberculosis is a bacterial infection that primarily affects the lungs. Therefore, the correct answer is A because it specifically describes the scarring and stiffness of the lungs resulting in breathing difficulties and inadequate oxygen intake.
Which condition involves the enlargement and weakening of the left ventricle of the heart, leading to reduced pumping ability?
- A. Dilated cardiomyopathy
- B. Hypertrophic cardiomyopathy
- C. Restrictive cardiomyopathy
- D. Pericarditis
Correct Answer: A
Rationale: The correct answer is A: Dilated cardiomyopathy. This condition involves the enlargement and weakening of the left ventricle, leading to reduced pumping ability. This results in the heart being unable to pump blood efficiently, causing symptoms like fatigue and shortness of breath. Hypertrophic cardiomyopathy (B) is the thickening of the heart muscle, not enlargement. Restrictive cardiomyopathy (C) involves stiffening of the heart muscle, not weakening. Pericarditis (D) is inflammation of the pericardium, not the heart muscle itself.
What is a condition where the heart muscle becomes abnormally enlarged, thickened, or stiffened, often leading to heart failure?
- A. Cardiomyopathy
- B. Pericarditis
- C. Aortic stenosis
- D. Mitral valve prolapse
Correct Answer: A
Rationale: The correct answer is A: Cardiomyopathy. Cardiomyopathy is a condition characterized by abnormal enlargement, thickening, or stiffening of the heart muscle, which can lead to heart failure. This condition directly affects the heart muscle itself, causing it to function improperly. Pericarditis (B) is inflammation of the pericardium, the outer lining of the heart, not the heart muscle. Aortic stenosis (C) and Mitral valve prolapse (D) involve issues with heart valves, not the heart muscle itself. Therefore, A is the correct choice as it directly addresses the abnormal changes in the heart muscle leading to heart failure.
What is the primary BP effect of β-adrenergic blockers such as atenolol (Tenormin)?
- A. Vasodilation of arterioles by blocking movement of calcium into cells
- B. Decrease Na+ and water reabsorption by blocking the effect of aldosterone
- C. Decrease CO by decreasing rate and strength of the heart and renin secretion by the kidneys
- D. Vasodilation caused by inhibiting sympathetic outflow from the central nervous system (CNS)
Correct Answer: C
Rationale: β-blockers reduce cardiac workload and renin release.
What term refers to the degree of myocardial fiber stretch before contraction, related to the volume of blood distending the ventricles at the end of diastole, and determined by the amount of venous return?
- A. Preload
- B. Afterload
- C. Contractility
- D. Ejection fraction
Correct Answer: A
Rationale: Rationale:
1. Preload refers to myocardial fiber stretch before contraction.
2. It is related to the volume of blood in ventricles at end of diastole.
3. Preload is determined by the amount of venous return to the heart.
4. It influences the force of contraction and stroke volume.
5. Afterload (B) is the resistance the heart must overcome to pump blood.
6. Contractility (C) is the intrinsic strength of the heart muscle.
7. Ejection fraction (D) is the percentage of blood ejected from ventricles.
Summary:
- Preload is correct as it specifically relates to fiber stretch and volume of blood.
- Afterload, contractility, and ejection fraction do not directly relate to ventricular volume and venous return.