What are the External Organs of the Human Body?

An external organ is any body part that is physically located on the outermost surface of the human body. Because they are on the outside, they are completely visible to the naked eye without needing an X-ray or surgery. Their primary jobs are usually to gather sensory information from the world (sight, hearing, touch) and to physically protect the fragile internal organs from damage and bacteria.

Most external organs are directly linked to our five basic senses:

1. The Eyes: For capturing light and giving us the sense of vision.
2. The Ears: For capturing sound waves and providing the sense of hearing (and maintaining body balance).
3. The Nose: For smelling chemicals in the air and serving as the primary air intake for breathing.
4. The Tongue: Though partially inside the mouth, it is considered an external sense organ for tasting food.
5. The Skin: The protective outer covering.

The Skin is by far the most important external organ. In fact, it is the absolute largest and heaviest organ in the entire human body. The skin acts as a massive, waterproof biological armor. It stops deadly viruses from entering the blood, regulates body temperature by sweating, and contains millions of nerve endings to give us the sense of touch, pain, and temperature.