الأسبوع 5 · المحور 1، الباب 2 «الحفاظ على صحة الجسم» (ج): القلب والنبض وكتابة تقرير · 3 دروس
1
My heart at work
Discover P3 Term 1: Axis 1, Chapter 2
GoalDescribe the heart as a muscle that squeezes blood round the body, carrying oxygen and nutrients.
New words
heart · a muscle about the size of your fist that pumps bloodblood · the red liquid that flows round the body in tubesoxygen · a gas in the air that the body needs to livepump · to push a liquid along
Explanation
Make a fist. Your heart is a muscle about that size, and it sits in the middle of your chest, a little to the left. The heart never rests. It squeezes and pushes blood out, then relaxes and fills up again. One squeeze is one beat. Blood flows along tubes to the lungs, where it picks up oxygen from the air we breathe. Then the heart pumps this blood to every part of the body. Blood carries oxygen and nutrients from food to our muscles, our brain and our skin. Then it travels back to the heart to be pumped again. Your heart works all your life, day and night.
Worked examples
Salma makes a fist and looks at it. “My heart is about as big as this!” she says. A baby’s heart is about as big as a baby’s fist, so it is smaller.
Karim squeezes a soft sponge ball in his hand and lets go, again and again. It is like the heart: squeeze, relax, squeeze, relax. Each squeeze is like one heartbeat.
Blood goes round like a loop: heart to the lungs to pick up oxygen, back to the heart, then to the whole body, and back again.
Class activity
Fist and sponge. Make a fist and compare it with a picture of a heart. Then squeeze a soft sponge ball 20 times, once each second, like a heart working. How do your fingers feel? Why can the heart keep working all the time without tiring?
Practice
1
The heart is a ____ about the size of your fist.
muscle
2
What does blood carry to every part of the body?
Oxygen and nutrients.
3
Where does blood pick up oxygen?
In the lungs.
4
You squeeze a soft ball 10 times in 10 seconds. What does one squeeze match in your heart?
