CARDIOVASCULAR SYSTEM
The cardiovascular system, also known as the circulatory system, is responsible for transporting blood, nutrients, oxygen, carbon dioxide, and hormones throughout the body.
| Heart: | A muscular organ which has four chambers: two atria (upper chambers) and two ventricles (lower chambers). |
| Blood Vessels: | The heart pumps oxygenated blood through the arteries to tissues and returns deoxygenated blood to the lungs via veins. Capillaries are tiny blood vessels where the exchange of oxygen, carbon dioxide, nutrients, and waste products occurs between blood and tissues. |
| Blood: | A bodily fluid that delivers essential substances like oxygen and nutrients to cells and removes waste products. It is composed of red blood cells, white blood cells, platelets, and plasma. |