🧬 Human Body

11 organ systems · microbiome · genetics & DNA · 37 trillion cells · click to explore each system

Select an organ system above to learn more.

What is this?

The human body is made up of 11 organ systems working together — from the skeletal and muscular systems to the circulatory, nervous, and digestive systems.

Why does it matter?

Understanding the body is the foundation of medicine, nutrition, and biology. Every doctor, nurse, personal trainer, and biologist uses this knowledge daily.

Key terms
Cell — the smallest unit of life; the body has roughly 37 trillion cells Tissue — groups of similar cells working together (muscle tissue, nerve tissue…) Organ — a structure made of tissues with a specific function (heart, liver, brain) Organ system — organs working together to perform a major body function Circulatory — heart + blood vessels; transports oxygen and nutrients throughout the body Nervous — brain + nerves; controls body actions and processes sensory signals
🎯 Try this challenge

Name one organ from each of these three systems: skeletal, digestive, and nervous. Explore each system in the diagram to verify your answers — did you get them all?

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