1. What is Normal Blood Flow Rate?

Definition: Blood flow rate (Q_b) is the volume of blood passing through a vessel per unit time.

Purpose: This calculator helps determine blood flow rate based on blood velocity and vessel cross-sectional area.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q_b \) — Blood flow rate (mL/min)
• \( V_b \) — Blood velocity (cm/s)
• \( A_v \) — Vessel cross-sectional area (cm²)

Explanation: The calculator multiplies blood velocity by vessel area and converts from cm³/s to mL/min (1 cm³ = 1 mL, multiplied by 60 seconds).

3. Importance of Blood Flow Rate

Details: Normal blood flow is essential for oxygen delivery, nutrient transport, and waste removal. The human heart pumps about 5-6 L/min at rest.

4. Using the Calculator

Tips: Enter blood velocity in cm/s and vessel cross-sectional area in cm². Typical values:

• Aorta: Velocity ~40 cm/s, Area ~2.5 cm²
• Capillaries: Velocity ~0.03 cm/s, Area ~4500 cm² (total)

5. Frequently Asked Questions (FAQ)

Q1: What's a normal blood flow rate for the human heart?
A: About 5-6 liters per minute at rest, increasing to 20-25 L/min during exercise.

Q2: How does vessel diameter affect flow rate?
A: Flow rate is proportional to the square of vessel radius (Poiseuille's Law).

Q3: What units does this calculator use?
A: Velocity in cm/s, area in cm², resulting flow rate in mL/min.

Q4: Can this calculate cardiac output?
A: Yes, if you measure velocity and area at the aortic valve.

Q5: How accurate is this calculation?
A: It provides theoretical flow; actual flow may vary due to viscosity, turbulence, and vessel elasticity.