The human body systems Different organs can work together to perform a common function, like how the parts of your digestive system break down food. We refer to an integrated unit as an organ system. Groups of organ systems work together to make complete, functional organisms, like us! There are 11 major organ systems in the human body.

Circulatory system The circulatory system is a body-wide network of blood, blood vessels, and lymph. Powered by the heart, it is the body’s distribution system to organs with oxygen, hormones and essential nutrients that helps it function properly. Read more. Learn more about these body parts in the circulatory system: heart

lungs

brain

kidneys

Respiratory system Every tissue within the body requires oxygen to function. The respiratory system, which includes air passages, pulmonary vessels, the lungs, and breathing muscles, provides oxygenated blood to the body tissues and removes waste gases. Read more. Learn more about these body parts in the respiratory system: nose

lungs

pharynx

bronchi

Skeletal system The skeletal system gives the body its basic framework, providing structure, protection, and movement. The 206 bones in the body also produce blood cells, store important minerals, and release hormones necessary to life. Read more.

Muscular system The muscular system is comprised of the sum total of muscles throughout the body that move the skeleton, maintain posture through steady contraction, and generate heat through cell metabolism. Humans have three types of muscle. Read more.