human body systems

The human body is made up of multiple interconnected systems that work together to keep you alive and healthy. The circulatory system, with the heart and blood vessels, transports oxygen and nutrients while removing waste. The respiratory system, including the lungs, helps you breathe by taking in oxygen and expelling carbon dioxide. The nervous system, comprising the brain, spinal cord, and nerves, controls body functions and reacts to your environment. The digestive system breaks down food into nutrients for energy. Muscular and skeletal systems provide movement and support. The immune system defends against infections, and the endocrine system regulates hormones for growth and development.