This system includes the heart, blood vessels (arteries, veins, and capillaries), and blood. It is responsible for transporting oxygen, nutrients, hormones, and waste products throughout the body. The heart pumps the blood, which circulates through the blood vessels to reach all tissues and organs.

The respiratory system consists of the organs involved in breathing, such as the lungs, trachea, bronchi, and diaphragm. Its primary function is to take in oxygen from the air and expel carbon dioxide from the body. This exchange of gases occurs in the lungs through tiny air sacs called alveoli.