Although our mouth is a small part of the human body, it is filled with several oral tissues that work together to help us eat, drink and speak. One of the key players of the mouth is the tongue. The tongue is one of the most active muscles in our body. The tongue occupies the majority of the oral cavity and oropharynx.
It is attached to the mouth by a network of tissues and mucosa. Though a tongue may seem like a simple organ, it has a variety of purposes. It helps in breathing, tasting, swallowing and articulating speech. Taste buds are specialized sensory receptors that can be found exclusively on the tongue.
We all have an idea about the anatomy of the teeth and the common diseases associated with the teeth. Understanding the anatomy and functions of the tongue is equally essential. Let’s read further to know more about the structure and functions of the tongue.
What is the tongue?
The tongue is a fleshy, muscular organ in the mouth. A moist, pink oral mucosa covers it. The surface of the tongue looks rough due to the presence of papillae. (1) The particular arrangements of fibers in the tongue allow it to move freely in the mouth. Our tongue mainly helps in mastication and swallowing. It is the primary organ of taste in the gustatory and digestive system. Typically, a human tongue measures around 3.3 meters in men and 3.1 meters in women.
What are the parts of a tongue?
There are three distinct divisions in a tongue –
Tip/Apex of the tongue
The anterior one-third of the surface of the tongue constitutes the apex. Tip of the tongue is mobile and is a center for nerve endings. Presence of nerve endings is probably the reason why you feel pain on biting the tip of the tongue. In addition to this, the taste buds for “sweet” are also present on the tip of the tongue. While speaking, the tip of the tongue helps to produce labiodental and alveolar sounds.
The body of the tongue
The body contains the anterior two-thirds of the tongue. Papillae of the tongue take up this space and give the surface a rough appearance. A thin lining of mucosa over the papillae keeps the surface moist. The body of the tongue contains the taste buds for salt, sour and bitter taste.
The base of the tongue
The base of the part is the posterior-most part that attaches to the floor of the mouth. This part is located between the mandible and the hyoid bone.
Hyoid bone primarily provides anchorage to the tongue.
The oropharynx is a part of the pharynx that is present between the soft palate and the epiglottis. It is the place where the dorsal portion of the base of the tongue is present.
What is the structure of a tongue?
A combination of three major divisions makes the structure of the tongue –
Papillae on the surface of the tongue
The lingual papillae give the characteristic appearance of the tongue. Papillae are small bumps on the surface of the tongue that contain taste buds.
Anatomically, the projections of the papillae are made by lamina propria and tongue epithelium.
There are four different papillae found on the surface of the tongue have unique functions– (2)
- Foliate – Helps in draining and cleaning
- Fungiform – Helps in taste
- Filiform – Responsible for sensations of touch
- Circumvallate – Helps in saliva production
Taste buds are specialized sensory receptors that are made of densely innervated basal cells.
Muscles of the tongue
The musculature of the tongue can be divided into four extrinsic and four intrinsic muscles.
As the name suggests the intrinsic muscles originate within the tongue and the extrinsic muscles have their origins outside the tongue.
A tough fibrous septum separates the muscles on each side of the tongue.
Both types of muscles work in coordination to allow different tongue movements. However, they also play individual roles; for example, extrinsic muscles change the position of the tongue while the intrinsic muscles help to change the shape of the tongue.
Vasculature and nerve supply of the tongue
The main blood supply to the tongue comes from the external carotid artery which branches of to join lingual artery.
The lingual artery has three divisions, namely, dorsal, deep and sublingual arteries. These branches provide blood to different parts of the tongue.
The hypoglossal nerve mostly innervates all the muscles of the tongue. (3)
What are the functions of a tongue?
The tongue has a wide range of functions in the oral cavity – (4)
- Tool to taste – One of the primary functions of the tongue is to be able to differentiate different types of tastes like sweet, sour, bitter and spicy. Taste buds play a significant role in determining this ability of the tongue.
- Mastication and chewing – Chewing and mastication are the two processes of digestion that start in the mouth. The tongue helps to mix the food particles with saliva and makes the food bolus. It facilitates positioning the food between the teeth while chewing.
- Swallowing – After the formation of food bolus in the mouth, the tongue aids in expelling the bolus into the esophagus.
- Speech – Tongue is an incredible organ of speech. Different parts of the tongue produce and modify sounds. The tips of the tongue produce labiodental sounds like L/ N/ R. The back of the tongue raises to produce k and G sounds. Intrinsic muscles help to change the shape of the tongue while speaking.
- An indicator of health – An interesting fact about the tongue is that it reflects the health of an individual. For example, a thick white coating on the tongue indicates a cold or viral infection. A thick yellow coat means inflammation and bacterial infections. The changes in the color and texture of the tongue provide a hint to the difference in the health of the individual.
Over to you
The tongue is a unique and multifunctional organ in the mouth. It is sensitive, moist and muscular.
Can you imagine what it would be like if we did not have a tongue in the mouth?
Tongue along with other structures in the mouth provides us our essential functions of chewing and swallowing. It primarily helps us to taste the delicious food we eat every day.
The tongue is a complex structure. The changes in the tongue can detect any difference in the health of an individual.
Keeping the tongue clean is vital to maintaining its health and functionality.