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Explore the Human Body

Learn about the 11 organ systems that keep the human body functioning every day.
Below, you’ll find interactive summaries of each system's purpose and role.

The 11 Organ Systems of the Human Body 📄 Download the PDF
The 11 Organ Systems of the Human Body
Anatomical organization:
Atoms → Molecules → Cells → Tissue → Organ → Organ System → Organism
Nervous
(signaling)
Coordinates body activities by detecting stimuli and directing responses using neurons.
Respiratory
(gas exchange)
Responsible for intake of oxygen and expulsion of carbon dioxide through the lungs.
Urinary
(waste)
Removes waste from the blood and regulates water and salt balance.
Muscular
(movement)
Allows movement of the body and internal organs through contraction.
Skeletal
(support structure)
Provides structure, protection, and support for the body and aids in movement.
Cardiovascular
(circulation)
Delivers oxygen and nutrients to tissues and removes waste through blood flow.
Reproductive
(sexual reproduction)
Produces sex cells and hormones for reproduction and supports developing embryos.
Lymphatic / Immune
(defense)
Defends the body against infections and transports lymph fluids.
Endocrine
(hormones)
Regulates body functions through hormones secreted into the bloodstream.
Digestive
(energy processing)
Breaks down food into nutrients that can be absorbed and used for energy.