"Health and Human Body" includes hands-on activities, online interactives and information on ways to stay healthy and how certain body systems work. All of these activities are in support of NIH SEPA created apps DIY Human Body, Monster Heart Medic, and "I Got This: An Interactive Story." This project was supported by the National Institutes of Health (NIH) Science
Arteries carry blood away from your heart, while veins carry blood toward your heart. One-way valves in your veins make sure blood travels only in one direction through your body. Tiny blood vessels called capillaries let nutrients and waste products be exchanged in all your cells.
Below your lungs, a muscle called the diaphragm pulls down to expand your lungs and pushes up to contract them. Your lungs are full of tiny sacs called alveoli, where oxygen enters and carbon dioxide exits your blood.
Your bones also protect you. Your skull protects your brain, and the vertebrae that make up your backbone protect your spinal cord. Your ribs protect some of your most important internal organs like your heart, lungs, liver, and spleen.
Some white blood cells in your immune system find and destroy disease-causing organisms. Other white blood cells create antibodies, which are proteins that help your body identify disease-causing organisms or cells they have infected. Some white blood cells are stored in your lymph nodes, which can become swollen when you’re sick.