What is the immune system? The immune system works to keep germs and other foreign substances out of the body and destroy any that get in. It's made up of a complicated network of cells and organs. It ...

What is the vascular system? The vascular system is made up of the vessels that carry blood and lymph fluid through the body. It's also called the circulatory system. The arteries and veins carry ...

The visual system is the part of the central nervous system that is required for visual perception – receiving, processing and interpreting visual information to build a representation of the visual ...

The nervous system is a complex network of nerves and cells that carry messages to and from the brain and spinal cord to various parts of the body. The proper functioning of these nerves ensures that ...

The musculoskeletal system is an organ system comprising the bones, muscles and connective tissues (including cartilage, tendons and ligaments) that bind tissues and organs together. The main ...

Narrator: Serious scientists, like myself, believe our Solar System was formed by the collapse of a giant cloud of gas and rock and is held together by the gravitational pull of the Sun. Eight planets ...

Will Kenton is an expert on the economy and investing laws and regulations. He previously held senior editorial roles at Investopedia and Kapitall Wire and holds a MA in Economics from The New School ...