Question

How did the valve influence the experimental results? Is possible, indicate the difference in water displaced( in ml) with the valve versus without the valve. does the valve enhance water flow? Why?

Heart valves and pumps experiment

Answer 1

HEART VALVES AND PUMPS EXPERIMENT:

• MATERIALS NEEDED: Wide Mouth Jar, Balloon, Wooden Skewer,2 flexible straws, scissors, Water, Tape,tub or pail to collect the water.
• PROCEDURE: ​​​​​​​

1. ​​​​​​​Fill the jar half full of water.
2. cut the neck of the balloon off at the part where it starts to widen into a balloon and set the neck park aside.
3. Stretch the balloon over the opening of the jar,pulling it down as tightly as you can.The flatter you can get the surface of the balloon,the better.
4. carefully, use the tip of a skewer to poke two holes in the surface of the balloon.Make them above about an inch apart from each other and near opposite edges of the jar.
5. Stick the long part of a straw into each hole and the straws should fit securely in the holes.So,no air can get through around the straws.
6. Slide the uncut end of the balloon neck onto one of the straws and tape around the straw.
7. Set your pump in a large pan or sink to catch the pumped water.Bend the straws downward and gently press in the center of the stretched balloon and observe what happens after pressing in the center of stretched balloon.

• OBSERVATIONS:

1. The cup is your heart
2. The pressing motion from your finger on the balloon is the pumping muscle
3. The water is your Blood
4. The straw with the balloon on it is the Atrial valve that keeps pumping of blood in wrong direction
5. The Other open ended straw is the ventricle through which the Blood flows
6. Assume for every press 1ml of water is displaced through the straw. With the valve presence, the water is displaced only through the straw without balloon and in the absence of the valve the water may leaks from the other straw too leading to more amount of water displacing from the jar.
7. For example, in the experiment we calculated the displacement of water for 10 presses wih valve and without valve with 1ml displacement of water.

With Valve, water displacement in ml	Without valve,water displacemt in ml
10 ml(only From the straw without tape)	20 ml(From the two straws)

• Valve increases the water flow only in one direction it prevents backward flow of water and decreases the pressure of flow.In Human Heart, the valves allows flow of blood in one direction which increases the blood flow,decreases the blood Pressure and decreases the strenght of contraction of the heart.