Did you ever wonder what all those complex body systems do? These Body Basics articles explain just how each body system, part, and process works. Use this medical library to find out about basic human anatomy, how it all functions, and what happens when things go wrong. Blood Bones, Muscles, and Joints Brain and Nervous System Digestive System Endocrine System Eyes Female Reproductive System Heart and Circulatory System Immune System Kidneys and Urinary Tract Lungs and Respiratory System Male Reproductive System Metabolism Mouth and Teeth Skin, Hair, and Nails Spleen and Lymphatic System Back to Articles Related Articles Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.