Teeth are the only part of the body that can't heal itself. A broken tooth stays broken forever. Did you know that your teeth are also mostly made of calcium? That's why eating calcium-rich food is essential because the calcium will help strengthen the tooth enamel.

Borborygmi is a stomach rumbling. It's a Greek word that means, well, rumbling. Ever hear that rumbling or gurgling noise made by the movement of fluid and gas in your intestines? It’s the sound of your hungry stomach grumbling like a crazy villain from a superhero movie.

The intergluteal cleft is commonly known as your butt crack. The intergluteal cleft is the gap of skin where your gluteus maximus muscle is located.

With a thickness of 0.2 mm, the eyelid has the thinnest skin on the body. The nerves that control the eyelid are divided into two bundles that respond to light and touch.

The jaw muscle–called the masseter–is the strongest part of the body. The masseter muscles are two sets of muscles in the human jaw. These are vital for chewing, swallowing, and speech.

With 27 bones in each one, the hands have the most bones. Put together, the hands have just over 26% of the bones in your body. This fact makes them the most complex bones in the human body!

The average tongue is about 3 inches long. Men's tongues at 3.3 inches are longer than women's tongues at 3.1 inches. The tongue is one of the most sensitive and fascinating parts of the body. Every cell in the tongue has a receptor and they all play a role in taste

If you include the bones that make up the ears, 29 bones constitute the head. These include the cranium, sphenoid, maxilla, mandible, and zygomatic arches, which hang from the skull by cartilage.

An adult's total skin mass (including nails and hair) weighs about 20 pounds. Human skin is comprised of 3 layers, the outer epidermis, and the inner dermis, and the hypodermis.

The femur, or thigh bone, is the longest (and strongest) bone in the human body. The femur is also the densest bone in the body, accounting for about 40% of your total weight after all other bones are accounted for. One of the strongest muscles of the body, the quadriceps, attaches to this bone.