The tongue is covered by mucosa which is a pink moist tissue. It is joined to the base of the oral cavity by a frenulum while the upper surface is free. It gets its rough texture from the papillae present on its surface. It has numerous taste buds all over that help in distinguishing different tastes like sweet, sour, bitter, and salty. The tongue has many nerves that transmit signals to the brain that help in taste sensation. Some of its uses are swallowing, licking, tasting, and speaking. The tongue also has salivary glands which secrete saliva. This saliva mixes with the chewed food to form a bolus which then passes through the esophagus for digestion.

The tongue is a primary muscular organ in the oral cavity. It is covered with a moist, pink tissue called the mucosa. There are tiny bumps which are called papillae which give the tongue its rough texture. Several thousand taste buds are located on the surface of the papillae which are collections of nerve-like cells that connect to nerves running to the brain. The tongue is anchored to the mouth by webs of tissue and mucosa and they tether holding down the front of the tongue which is known as the frenum. At the back of the mouth, the tongue is anchored to the hyoid bone. The tongue is the vital organ for the taste of food, chewing, swallowing, and speech.

What is Tongue?

The tongue is a mighty flexible organ. It’s the fleshy muscular organ in the mouth of a mammal, used for tasting, licking, swallowing, and helping humans to speak. It helps to swallow food in mammals. The tongue is a primary muscular organ in the oral cavity. It is covered with a moist, pink tissue called the mucosa. There are tiny bumps which are called papillae which give the tongue its rough texture

Structure of Tongue:

The tongue is divided into tip, body, and base. It has a posterior and anterior parts. The anterior part contains the frenulum that attaches the base of the tongue to the oral cavity while the posterior part contains the tip and body of the tongue.  The tongue consists of three layers –

• Epithelium
• Muscles
• Glands

1. Epithelium: This layer contains the papillae and taste buds. They have a squamous epithelium layer lining. The cells that help in the tasting are rod-shaped and have a nucleus in the canter. Its main function is to help to detect the taste.

2.Muscles:  The muscles present in the tongue are voluntary and the muscle fibers are cross-striated.

3.Glands: The tongue has glands scattered all over it and is small in size.

• They are of three types – mucous, serous, and lymph nodes. The most prominent one among the three is the lymph nodes in the posterior part of the tongue.

4. Nerve supply: The glossopharyngeal nerve and the chorda tympanic branch of the facial nerve are responsible for a taste sensation. The sensations of pain, touch, and temperature are carried by the trigeminal nerve.

In males, the tongue is about 3.3 inches in length, whereas the female tongue is about 3.1 inches in length.

The tongue also contains the salivary glands. These glands are of three types and are present in pairs.

1. Parotid – It is located on the inner surface of the cheek.
2. Submaxillary – It is present on the floor of the oral cavity on both the sides of the frenulum.
3. Sublingual – It is also present on the floor of the oral cavity on both the sides of the frenulum.

Tongue and its parts:

Most of the tongues are 10 cm in length and are divided into two definite parts –

• The most mobile part of the tongue is called the apex or its tip. 
• The tongue has a rough dorsal surface.
• The tongue has lingual papillae and taste buds.
• It has a smooth ventral surface on the floor attached to the oral cavity.

These two parts, an anterior two-thirds, and a posterior one-third are structurally and developmentally distinct. 

1. Anterior two-thirds: The anterior part of the tongue includes the apex and body of the organ and it ends at the sulcus terminals; this part extends laterally in an oblique direction from the foramen cecum towards the palatoglossal arch. The mucosa layer of the dorsal surface is made of 

• Vallate papillae: are arranged in a V-shape anterior to the sulcus terminalis and studded with numerous taste buds. Innervation is by the glossopharyngeal nerve.
• Fungiform papillae are mushroom-shaped papillae with erythematous domes located on the lateral aspects and at the apex of the tongue.
• Filiform papillae are slim, cone-shaped projections organized in rows parallel to the sulcus terminalis.
• Foliate papillae are rarely found in humans (vestigial).

2. Posterior one-third: The posterior third part of the organ is made up of the base of the organ. It is located behind the palatoglossal folds and functions as the anterior wall of the oropharynx. This part does not have any lingual papillae and the mucosa is populated by lymphatic tissue known as lingual tonsils.

What is the area under the tongue? 

• Below your tongue is a horseshoe-shaped area of tissue known as the floor of the mouth. This flat area of soft tissue has a separate rising fold of tissue that connects it to the underside of the tongue, known as the lingual frenulum.
• The lingual frenulum is a fold of mucus membrane that’s located under the center portion of your tongue. If you look in the mirror and lift your tongue, you’ll be able to see it. The lingual frenulum helps to anchor your tongue in your mouth.
• On either side of the frenulum are small prominences called sublingual caruncles.

Functions of Tongue:

The functions of the tongue include:

• Mastication: This means chewing food or any object. It helps in chewing food with the help of saliva.
• Deglutition: The tongue also helps in swallowing food.
• Taste: Taste buds on the tongue transmits taste signals to the brain and assist in sensing taste.
• Speech: Tongue plays a direct role in facilitating speech.
• Secretion: The organ also secretes mucous and serous fluid keeping the mouth moist.

Conclusion:

The tongue is an important organ that contributes to speech, mastication, deglutition, and taste. Your tongue helps you taste, eat, digest, and speak. While you chew the tongue assists with moving the food and swallowing. The small bumps, or papillae, on the tongue, allow you to taste. The tongue is an agile and flexible muscle, giving it the ability to produce many words.