8 Circulation of blood Blood circulation The function

8. Circulation of blood §Blood circulation §The function of circulatory system §The structure of the circulatory system §Blood donation §Blood groups §Excretion Std. 7 th Sub. - Science 8. Circulation of blood

• Blood circulation-Many substances like water, oxygen, soluble food materials, and waste substances are exchanged between the parts of the body Std. 7 th Sub. - Science

• Functions of circulatory system • Soluble substances • Oxygen • Hormones • Waste products Std. 7 th Sub. - Science 8. Circulation of lood

• The structure of the circulatory system • Heart-a muscular organ. Std. 7 th Sub. - Science 8. Circulation of blood

• Arteries-carry blood from heart to different parts of the body. Veins-carry blood from different parts of the body to the heart

• Capillariesare the blood vessels which are as fine as hair.

Blood donation • The action of a healthy person giving blood for use by a patient is called blood donation.

• The person who donates blood is called donor.

The person who receives blood is called receiver

Blood Groups • A, B, AB, O are the four blood groups. • Universal donor-O • Universal receiver-AB

Excretion • The process of passing out waste substances from the body is called excretion. • Waste substances-urea , ammonia, salts.

• Waste products in plants- Colacosia leavescalcium oxalate. Rubber – sap Khair-katechu Baboolgum

Question hour • • • 1 Define excretion. 2 Name the waste products formed in plants. 3 Name the parts of human circulatory system. 4 Give reason-The walls of capillries are thin. 5 Write a note on blood donation.

Rayat Shikshan Sanstha , Karmveer Vidhyaprabhodhini Madhya Vibhag , Satara • Blood circulation • The function of circulatory system • The structure of the circulatory system Spp. P • Blood donation • Blood groups • Excretion Std. 7 th Sub. - Science 8. Circulation of blood

Rayat Shikshan Sanstha , Karmveer Vidhyaprabhodhini Madhya Vibhag , Satara Spp. P Std. 7 th Sub. - Science 8. Circulation of blood