The immune system is the body’s tool for preventing or limiting infection. Its complex network of cells, organs, proteins, and tissues enables the immune system to defend the body from pathogens. A ...

The respiratory system is responsible for the exchange of carbon dioxide and oxygen in the human body. This system also helps remove metabolic waste products and keep pH levels in check. The major ...

The endocrine system uses chemical messengers called hormones to regulate a range of bodily functions through the release of hormones. The endocrine system is a network of glands and organs located ...

Your nervous system is a network that sends signals between your brain and other parts of your body to control your body's movements and processes. This system includes your brain, spinal cord, and ...