In 3-5 sentences, simply describe the human respiratory system and its functions.

The human respiratory system is a network of organs and tissues that help us breathe. It includes the nose, trachea, lungs, and diaphragm. The main function of the respiratory system is to bring oxygen into the body and remove carbon dioxide. This process is essential for the body to function properly and for cells to produce energy. Additionally, the respiratory system helps regulate the body's pH levels and plays a role in vocalization.