What happens to flow if vessel length is decreased, assuming all other factors remain constant?

• A. Flow increases
• B. Flow decreases
• C. Flow remains the same
• D. Flow fluctuates

Answer: (A)

When the length of a vessel decreases while keeping all other factors constant, the flow increases due to the relationship established by Poiseuille's law. This law describes how various factors affect the flow rate of a fluid through a cylindrical vessel.

According to Poiseuille's law, flow rate is inversely proportional to the length of the vessel. Specifically, as the length of the vessel decreases, the resistance to flow also decreases. Flow is defined as the pressure difference divided by the resistance. If resistance decreases due to shorter vessel length, for a constant pressure difference, the flow rate must increase.

Thus, by understanding the relationship between vessel length and flow resistance, it becomes clear that reducing vessel length results in an increase in flow.