- Answer: (A) Left ventricle
- Explanation: The left ventricle is responsible for pumping oxygenated blood to the entire body. This requires a strong muscular wall to generate enough force for efficient blood flow. Therefore, the left ventricle has the thickest wall compared to other chambers.
- Answer: (B) Ventricular Diastole
- Explanation: The “lubb” sound is the first heart sound, which occurs when the atrioventricular valves (mitral and tricuspid) close at the beginning of ventricular diastole (relaxation).
- Answer: (B) Pericardium
- Explanation: The pericardium is a double-layered sac made of fibrous tissue (outer layer) and serous membrane (inner layer). It surrounds the heart, providing support, protection, and lubrication.