1. Introduction
The circulatory system is responsible for transporting oxygen, nutrients, hormones, and waste
products throughout the body. It helps maintain body temperature and supports overall survival.
2. Components of the Circulatory System
The system is made up of three main parts:
a) Heart
A muscular organ located in the chest.
Pumps blood to all parts of the body.
Divided into four chambers:
oRight Atrium
oRight Ventricle
oLeft Atrium
oLeft Ventricle
The left ventricle has the thickest wall because it pumps blood to the entire body.
b) Blood Vessels
These are tubes that carry blood.
1. Arteries
oCarry blood away from the heart.
oHave thick elastic walls.
oBlood flows under high pressure.
2. Veins
oCarry blood back to the heart.
oHave valves to prevent backflow.
oBlood flows under low pressure.
3. Capillaries
oVery tiny vessels.
oAllow exchange of oxygen, nutrients, and waste.
c) Blood
