Dr Rao is reading in his study. The door bursts open and Anil and Sabina rush in.
Anil: (breathing heavily) Grand mother what’s this thing thumping away in my chest?
Grandmother: (laughing and putting his ear to Anil’s chest) that’s your heart. It says you have run up two flights of stairs.
Anil: We had a race up the stairs.
Grandmother: And your heart helped you run the race.
Grandmother: I’II tells you. First show me your fists, children. (Anil and Sabina hold their first up and lightly punch each other.) That is the size of your heart. Put your hand on your chest. Can you feel your heart beating?
Anil: Dug! Dug! Dug!
Grandmother: That’s the sound of it pumping blood around your body.
Sabina: (brightly) like the pump down stairs’ pumping water to the second floor.
Grandmother: Yes. The pipes that carry blood from the heart to the body are called arteries. And the tubes that carry blood from all parts of parts of the body to the heat are called veins. Let me see your veins.
Anil: (startled) you mean you can see them? It’s your pulse. At your age it is about 85 beats minute.
Sabina: How many times in a week?
Anil: In a month?
Sabina: In a year? (They both try to calculate and give up.)
Grandmother: I’II tells you! Your heart pumps forty –four million times in a year!
Sabina: (impressed) it must be very strong
Grandmother: It is it’s made of muscle.
(Anil shows off the muscles on his arm.)
Sabina: But how does it pump?
Grandmother: By contracting. That makes it smaller so blood gets squeezed out into the arties. Then it relaxes and the heart fills up with blood again.
Anil: How much blood does it pump out at each beat?
Grandmother: About a cupful.
Sabina: is the heart very heavy
Grandmother: No, it isn’t. It weighs about as much as a grapefruit. Look at this picture. It shows what the heart would look like when sliced open
Anil: Imagine our blood is moving around all the time!
Sabina: and we don’t even feel it moving!
Anil: Grandmother! How much blood do I have in my body?
Grandmother: About 5.5 Liters. That’s nearly half a bucket.
Sabina: But what does blood do?
Grandmother: It’s like a river. It is Carries things.
Anil: What things?
Grandmother: Well, our bodies need oxygen. We breathe Oxygen into our Lungs. From there our blood carries it around to the rest of the body. It also carries cardoon dioxide from the body to the Lungs.
Anil: And we breathe out cordon dioxide?
Grandmother: Yes. Blood also protects us.
Grandmother: Remember, Sabina when you cut your finger how quickly the cut closed up? That is because blood sets or clots quickly. So it prevents dirt and germs from entering the wound. Also there are white blood cells which attack germs in the blood and eat them up.
Anil: (Pretending to attack Sabina) Arrgh! I’m a white blood cell. I’m going to eat you up!
Grandmother: So keep your heart strong and healthy if you want it to work well.
Anil: And how do we do that?
Grandfather: By eating nourishing food and getting plenty of exercise. That reminds me| – it’s times for my evening walk! Coming?
Anil and Sabina: We will race you!