The fact that the left ventricular wall is thicker than the right reveals that it a. pumps a greater volume of blood, b. pumps blood against greater resistance, c. expands the thoracic cage, d. pumps blood through a smaller valve.

Verified step by step guidance

1. Understand the function of the left and right ventricles: The left ventricle pumps oxygenated blood to the entire body, while the right ventricle pumps deoxygenated blood to the lungs.
2. Consider the resistance each ventricle faces: The systemic circulation (served by the left ventricle) has higher resistance compared to the pulmonary circulation (served by the right ventricle).
3. Relate wall thickness to function: A thicker wall in the left ventricle suggests it needs to generate more force to overcome the higher resistance in the systemic circulation.
4. Evaluate the options: Compare the function and resistance faced by each ventricle to determine which option best explains the thicker wall of the left ventricle.
5. Conclude that the thicker wall of the left ventricle is due to the need to pump blood against greater resistance, aligning with option b.

Key Concepts

Left Ventricular Hypertrophy

Left ventricular hypertrophy refers to the thickening of the heart's left ventricle wall, which occurs due to increased workload. This adaptation is necessary because the left ventricle is responsible for pumping oxygenated blood to the entire body, requiring more force and strength compared to the right ventricle, which only pumps blood to the lungs.

Systemic vs. Pulmonary Circulation

Systemic circulation involves the movement of blood from the heart to the rest of the body, while pulmonary circulation refers to blood flow from the heart to the lungs. The left ventricle pumps against the higher resistance of systemic circulation, necessitating a thicker wall to generate sufficient pressure, unlike the right ventricle, which pumps against lower resistance in pulmonary circulation.

Cardiac Output and Stroke Volume

Cardiac output is the volume of blood the heart pumps per minute, influenced by stroke volume and heart rate. The left ventricle's thicker wall allows for a greater stroke volume, enabling it to pump a larger volume of blood effectively. This is crucial for meeting the metabolic demands of the body's tissues during physical activity or stress.