The tongue is a muscular organ in the mouth covered with a moist, pink tissue called the mucosa. It is involved in licking, tasting, breathing, swallowing, and speaking. The papillae present on the organ give it a rough texture. It is covered by several taste buds. There are several nerves in the tongue that help in transmitting taste signals to the brain, and thus help in taste sensation. A major function of the tongue is the enabling of speech in humans and vocalization in other animals.
Structure of Tongue
The human tongue is about 3.3 inches in men and 3.1 inches in women. The organ is located in the oral cavity. It is divided into three parts:
It is embryologically divided into the anterior and posterior parts. The anterior part is known as the oral or presulcal part which includes the root attached to the floor of the oral cavity.
The tongue is made up of three elements:
- Epithelium: The epithelium comprises papillae and taste buds. The taste buds help to sense taste. They are lined by squamous epithelial tissue and have a broad bottom. The taste cells are slender and rod-shaped with a nucleus in the center. The free surface comprises short taste hair. The taste cells help in detecting taste, which dissolves in saliva for proper sensation.
- Muscles: The muscles are voluntary and contain cross-striated muscular fibers.
- Glands: The tongue consists of small and scattered glands. These glands are of three types they are Mucous Glands, Serous Glands, and Lymph Nodes. The lymph nodes are very prominent at the posterior part of the tongue and are known as lingual tonsils.
Functions of Tongue
- Mastication: This means chewing food or any object. It helps in chewing food with the help of saliva.
- Deglutition: It also helps in swallowing food.
- Taste: The tongue transmits taste signals to the brain and helps in sensing taste.
- Speech: It is an important organ that facilitates speech.
- Secretion: The organ also secretes mucous and serous fluid keeping the mouth moist.
Salivary glands comprise three pairs:
- Parotid: It opens on the inner surface of the cheek by the duct of Stensen. It is located opposite the second upper molar tooth.
- Submaxillary: It opens by Wharton’s duct on the floor of the mouth by the sides of the frenulum of the tongue.
- Sublingual: It opens by the ducts of Rivinus on the floor of the mouth by the sides of the frenulum of the tongue.