Beat volume is

Options

A. 30mL
B. 5L
C. 100mL
D. 70mL

Answer

**Step-by-Step Solution:**

1. **Understanding the Term "Beat Volume":**
- Beat volume is also known as stroke volume. It refers to the amount of blood that is pumped by each ventricle of the heart during one complete heartbeat or cardiac cycle.

2. **Definition of Stroke Volume:**
- Stroke volume (or beat volume) is defined as the volume of blood ejected from each ventricle during a single cardiac cycle.

3. **Typical Value of Stroke Volume:**
- The average stroke volume for a healthy adult is approximately 70 ml. This means that during each heartbeat, each ventricle pumps out about 70 ml of blood.

4. **Understanding Cardiac Output:**
- Cardiac output is the total volume of blood pumped by the heart per minute. It can be calculated by multiplying the stroke volume by the heart rate (number of beats per minute).
- For example, if the heart beats 72 times per minute and the stroke volume is 70 ml, the cardiac output would be:
\[ \text{Cardiac Output} = \text{Stroke Volume} \times \text{Heart Rate} = 70 \, \text{ml} \times 72 \, \text{beats/min} = 5040 \, \text{ml/min} \approx 5 \, \text{liters/min} \]

5. **Conclusion:**
- Since the question specifically asks for the beat volume, the answer is 70 ml, which corresponds to the volume of blood pumped by each ventricle during a single cardiac cycle.

**Final Answer:**
- The beat volume is **70 ml** (Option 4).

---