It takes but a quick look inside of the mouth to see that there’s more to it than the teeth. There’s the tongue, a bundle of supple muscles that extends from the floor of the mouth. The front of the tongue is anchored by a bit of tissue called the frenum, while the back of the tongue is attached to the hyoid bone. The tongue is of course vital for helping people chew and swallow their food, and contains papillae and taste buds. The tongue also plays a vital role in speech. On average, the tongue of a human is about four inches long.

Also in the mouth cavity is the hard palate, which is the bony front part of the roof of the mouth, and the soft palate, which is the soft part found in the rear. The hard palate creates a partition between a person’s mouth and their nose. The soft palate curves down at the back of the mouth to form a partition between the mouth and the pharynx. The uvula is that structure that looks like a punching bag at the end of the soft palate. Though it helps somewhat with speech, scientists aren’t really sure why the uvula evolved.

The pharynx, which is the back of the mouth, connects the nose and the mouth with the esophagus and the trachea. The esophagus is the tube that conveys food to the stomach, and the trachea is the tube that carries air to the lungs.

Behind the uvula, on either side of the mouth cavity, are the palatine tonsils, which are made up of lymph tissue. They are the most visible of what’s called the tonsillar ring. Others are the adenoids and the tubal tonsils, which are at the top of the pharynx and the lingual tonsils, which are behind the tongue. They are part of the body’s immune system.

Some of the most important structures of the mouth also can’t be seen. These are the salivary glands. The parotid glands, found in the cheeks, are the largest salivary glands. The submandibular glands are found in the lower jaws, and the sublingual glands are found beneath the tongue. Humans have many, much smaller salivary glands in the mouth. The saliva they produce helps people chew and swallow food, supports the health of the teeth and gums and contain enzymes that break down starches. This is the first step in digestion.