End systolic volume of blood is the quantity of blood present

Options

A. in ventricles after atrial systole
B. in ventricles after ventricular systole
C. in ventricles before the opening of semilunar valves
D. in atria before the closure of AV valves.

Answer

To solve the question regarding the end systolic volume of blood, we will break down the concept step by step.

### Step-by-Step Solution:

1. **Understanding Cardiac Cycle**: The cardiac cycle consists of two main phases: diastole (relaxation) and systole (contraction). During systole, the heart contracts to pump blood out of the ventricles.

2. **Atrial Systole**: The cycle begins with the contraction of the atria, known as atrial systole. This phase pushes blood into the ventricles.

3. **Ventricular Systole**: Following atrial systole, the ventricles contract in a phase called ventricular systole. During this phase, the blood is pumped out of the ventricles into the arteries.

4. **End Systolic Volume (ESV)**: After the ventricles have contracted and pumped out blood, there is still some blood remaining in the ventricles. This remaining volume of blood is referred to as the end systolic volume (ESV).

5. **Quantity of ESV**: The typical quantity of blood that remains in each ventricle after contraction (end systolic volume) is approximately 50 ml.

6. **Identifying the Correct Option**: The question asks for the location of the end systolic volume. Since ESV is the volume of blood present in the ventricles after ventricular systole, the correct answer is:
- **Option B**: In ventricles after ventricular systole.

### Final Answer:
The end systolic volume of blood is the quantity of blood present in the ventricles after ventricular systole. Therefore, the correct option is **B**.

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