The mouth is lined with mucous membranes that protect the inside of your mouth and keep it moist. If the proper moisture level is not maintained, problems can result. This could be 'dry mouth', an abundance of bacteria because it is not being washed away properly, or a number of other problems.

To keep the mouth moist there are three pairs of salivary glands in the walls and floor of the mouth. They secrete saliva, which contains a digestive enzyme called amylase that starts the breakdown of carbohydrates even before food enters the stomach.

The tongue is mostly muscle. It is covered with a mucous membrane.

Top of the Tongue

The top side of the tongue is called the dorsum and can be divided into two parts: the front that lies mostly in the mouth (anterior), and a back part that faces backwards (posterior). The anterior makes up two thirds of the tongue, with the posterior making the final third.

The front and back parts are separated by a V-shaped groove, called the sulcus terminalis (or terminal sulcus). The line down the middle of this is called a median furrow.

The top surface of the tongue is covered with bumps. These are called papillae; they are not the taste buds these are actually nestled between the papillae. There are four types of taste buds: filiform, fungiform, vallate, and foliate. The taste buds react to four stimuli: sweet, salty, bitter, and sour.

The tongue moves food around in your mouth to aid chewing and swallowing, and it is important in speech. Changes in the looks of the tongue may indicate a primary tongue problem or may just be a symptom of another problem.

Bottom of the Tongue

This is covered with a smooth mucous membrane, with a fold called the lingual frenulum in the center. The frenulum is the band of tissue that connects the bottom of the tongue to the floor of the mouth.

Muscles of the Tongue

There are four pairs of muscles that act to move the tongue. They are attached to various bones of the head and neck. These muscles are called:

• Genioglossus this muscle comes from the lower jaw (mandible) and makes up most of the bulk of the tongue.

• Hyoglossus the root of the tongue is attached to the hyoid bone in the neck.

• Styloglossus comes from the bones that are located at the sides and base of the skull.

• Palatoglossus lifts the back of the tongue and helps the beginning of swallowing.

The tongue muscle is often considered to be the strongest in the body!

Nerves of the Tongue

Nerves from the tip of the tongue connect to the brain to send taste sensations into the memory. The tongue is also very sensitive to texture.

Tongue Structure and Unhealthy Tongues

The tongue is often considered to be very much like a "gauge" of the rest of the body's condition. If you go to see the doctor about a health problem, the doctor often asks to see your tongue first! By understanding how the tongue is made up, certain common signs (like bald patches) can quickly be explained by certain nutrient deficiencies or lifestyle choices.