The circulatory system consists of three main parts:
- Heart : A muscular organ with four chambers (right atrium, right ventricle, left atrium, left ventricle) that pumps blood throughout the body. It has valves that regulate blood flow between chambers and into major blood vessels
- Blood vessels : These include arteries (carry oxygenated blood away from the heart), veins (carry deoxygenated blood back to the heart), and capillaries (tiny vessels where exchange of oxygen, nutrients, and waste occurs between blood and tissues)
- Blood : The fluid that transports oxygen, nutrients, carbon dioxide, and waste products. Blood consists of plasma, red blood cells, white blood cells, and platelets
The system is divided into two main circulations:
- Pulmonary circulation : Carries deoxygenated blood from the right side of the heart to the lungs for oxygenation, then returns oxygen-rich blood to the left side of the heart
- Systemic circulation : Delivers oxygenated blood from the left side of the heart to the rest of the body and returns deoxygenated blood back to the right side of the heart
In summary, the parts of the circulatory system are the heart, blood vessels (arteries, veins, capillaries), and blood, working together to circulate blood and maintain oxygen and nutrient delivery throughout the body.
