The nervous system has two major parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The central system is the primary command center for the body, and is comprised of ...

The system of blood vessels in the human body measure about 60,000 miles (96,560 kilometers). Arteries carry oxygen-rich blood from the heart through the body.

Think of cortisol as nature’s built-in alarm system. It’s your body’s main stress hormone. It works with certain parts of your brain to control your mood, motivation, and fear. Your adrenal ...