Dear Grade 6 learners, do you know that the heart is a very important organ in your body? In this CBE Grade 6 notes, we’re going to learn why this is so, including other parts of the heart. And let me add a poem to help you master some concepts too!
The heart is part of the circulatory system. That system includes the heart, blood vessels, and blood.
a) The heart has four chambers:-
- Right atrium
- Right ventricle
- Left atrium
- Left ventricle
b) Your blood, dear Grade 6 learner, is made up of plasma, red blood cells, white blood cells and platelets. What do those four do? You’re about to learn that in this CBE Grade 6 notes.
But before that, you need to know that the bone marrow is responsible for making blood cells. Red blood cells live for about 4 months while platelets only for a week!
- Platelets – stop bleeding when you’ve been injured.
- White blood cells – fight pathogens and defend the body from infections.
- Red blood cells – transports oxygen from lungs to body tissues.
- Plasma – a yellowish substance that transports cells, hormones, waste.
c) Blood vessels include arteries, veins, and capillaries.
Arteries carry blood from the heart to the whole body. Because arteries carry blood from the heart, they have to be thick and strong in order to withstand the pressure.
Veins carry used blood, that is oxygen-poor blood back to the heart apart from the pulmonary vein which carries oxygen-rich blood from your lungs to the heart. Veins also have valves to prevent blood from flowing backwards.
Blood Groups
There are four main blood types: A, B, O, and AB. O-negative is the universal donor, while AB-positive is the universal recipient. Type O+ is the most common while AB- is the rarest.
Fun fact
Did you know that crabs have blue blood!
Here Are Some Fun Facts About The Heart
- Your heart beats about 100,000 times a day!
- It’s about the size of your fist.
- Your heart pumps about 5 litres of blood every minute.
- The heart has its own electrical system and this allows it to beat even when taken out of the body for a short time!
- The left side of your heart is stronger than the right. This is because the left ventricle pumps blood to the whole body, so its muscles are thicker.
- Your heart rate changes based on your emotions. You’ve probably noticed that when you’re excited, nervous or scared, your heart beats faster.
- A baby’s heart beats faster than an adult’s. A newborn’s heart beats about 120–160 times per minute, while an adult’s beats around 60–100 times per minute.
Your heart is a hardworking organ that keeps your body running. Do you know what that reminds me of? A car engine!
the human heart