Page 19 - Viva ICSE Science 5 : E-book

Process of Circulation

Blood keeps on circulating between the
lungs
heart and the rest of the body.
pulmonary pulmonary
Purifi ed oxygenated blood from the lungs
artery vein
enters the left auricle. From left auricle,

it enters the left ventricle which pumps vena cava aorta
blood to various tissues and organs of heart

the body through arteries. The arteries
divide into capillaries in the body tissues

and organs. Here, the blood passes on the
nutrients and oxygen, and collects carbon
capillaries s
dioxide and waste materials. This impure
= oxygenated blood
deoxygenated blood (rich in carbon
= deoxygenated blood
dioxide) collected by the capillaries now
Path of blood
fl ows into the veins. Veins carry the blood

back to the heart into the right auricle. From here, the blood is passed on to the right
ventricle, from where it is pumped to the lungs for purifi cation. The pure blood returns

to the left auricle. In this manner, the circulation of blood continues.

TERMS TO KNOW

1. Organ system: A group of organs that work together to carry out a particular function

2. Circulatory system: The system that helps in the transportation of substances to and from
various parts of the body
3. Heart: A muscular organ that acts like a pump to force blood throughout the body
4. Auricles: The two upper chambers of the heart

5. Ventricles: The two lower chambers of the heart
6. Blood: A red-coloured fl uid which fl ows inside the blood vessels
7. Blood vessels: A network of tubes and channels inside the body through which blood
fl ows

8. Arteries: The blood vessels that carry oxygen-rich blood from the heart to diff erent body
parts
9. Veins: The blood vessels that carry oxygen-defi cit blood from diff erent parts of the body to
the heart

5