The heart is the most powerful organ in the circulatory system. It is located in the thoracic cavity between the lungs and pumps blood throughout the body. The heart has four chambers - two atria which receive blood and two ventricles which pump blood out. The right side contains deoxygenated blood while the left side contains oxygenated blood. The heart contracts to pump blood into the arteries and relaxes to receive blood from the veins, ensuring circulation throughout the body.

2. Blood circulation
By
Neethu Sivan S

3. • What organ need to pumps blood to the whole body???

4. • Transport System in Humans
The human circulatory system consists of:
1. The heart
2. Blood vessels
3. Blood

7. HEART
• Most powerful organ in the circulatory system.
• Cone-shaped organ.
• Weight about 300g.
• Location: in the thoracic cavity, between the lungs.
• A muscular organ made up of cardiac muscles connective tissues and
blood vessels.
• The heart pumps blood to the whole body.

8. • The human heart consists of four chambers:
a) right atrium
b) left atrium
c) right ventricle
d) left ventricle
• The heart is connected to four main blood vessels
i) vena cava
ii) pulmonary vein
iii) pulmonary artery
iv) aorta

9. • The valves separate the atria/ atrium from the ventricles. To ensure
that the blood flows only in one direction.
• right side of the heart contains deoxygenated blood
• left side of the heart contains oxygenated blood (blood rich in
oxygen).
• Function the parts in the heart:

10. Function of the heart:
1. pumps blood to the whole body.
2. The right side of the heart contains deoxygenated blood.
3. Left side of the heart contains oxygenated blood.
4. When the heart contracts, it forces the blood out of the heart into
the arteries.
5. When it relaxes, it receives blood from the veins.

14. Questions
• How does the blood reach all parts of the body?
• What are the parts included in the blood circulatory system?
• What are the peculiarities of human heart ?
• Do all organisms have a heart ?
• Does the heart of all organisms have four chambers?

15. Home work
• Make a model of heart with house hold materials and exhibits in
science fair
• Write note on the process of blood circulation