22 Questions
What happens to the velocity of water when a narrow nozzle is attached to the end of a hose?
It speeds up
Why does blood slow down as it moves from arteries to capillaries?
Because of the enormous increase in cross-sectional area
What is the approximate ratio of blood flow velocity in the aorta to that in the capillaries?
500:1
What happens to the velocity of blood after passing through the capillaries?
It speeds up
Why does the cross-sectional area increase in capillary beds?
Because each artery conveys blood to many capillaries
How many capillaries are there in a human body?
7 billion
What is the direction of blood flow due to contraction of the heart ventricle?
Away from the heart
What role does the recoil of the elastic arterial walls play in the cardiac cycle?
Maintains blood pressure
What is the main reason for the substantial resistance to flow in the arterioles and capillaries?
Narrow diameter of the vessels
What happens to the pressure generated by the pumping heart by the time the blood enters the veins?
It is dissipated
What is the force exerted by the contraction of the heart ventricle that stretches the wall of the artery?
Sideways force
What is the primary direction of the force generated by the contraction of the heart ventricle?
In all directions equally
What is the effect of the recoil of the elastic arterial walls on blood pressure?
It maintains blood pressure
What is responsible for the flow of blood away from the heart?
The part of the force directed lengthwise in the artery
What is the main reason for the decrease in blood pressure in the veins compared to the arteries?
The resistance to flow in the arterioles and capillaries
What is the characteristic of blood flow that allows it to flow from areas of higher pressure to areas of lower pressure?
Its fluidity
What happens to the water velocity when a narrow nozzle is attached to the end of a hose?
It speeds up
Why does the blood flow velocity decrease in the capillaries?
Because of the increased cross-sectional area
What is the significance of the large number of capillaries in the human body?
It increases the total cross-sectional area
What happens to the blood flow velocity after passing through the capillaries?
It increases
What is the reason for the analogy between the hose and the circulatory system?
Both have incompressible fluids
What is the primary reason for the dramatic decrease in blood flow velocity from the arteries to the capillaries?
Enormous increase in cross-sectional area
Understand how blood vessel diameter affects blood flow by analyzing the flow of water through a hose with a narrow nozzle. Learn how the volume of water moving through the hose remains constant, and how this relates to blood flow velocity.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
