The tongue is a muscular organ in the mouth covered with a moist, pink tissue called mucosa. It is involved in licking, tasting, breathing, swallowing, and speaking. The papillae present on the tongue give it a rough texture. It is covered by a number of taste buds. There are several nerves in the tongue that help in transmitting taste signals to the brain, and thus help in taste sensation.
Let us explore the structure, parts and functions of tongue in detail.
Also Read: Sense Organs
Structure of Tongue
The human tongue is about 3.3 inches in men and 3.1 inches in women. It is located in the oral cavity. The tongue is divided into three parts:
The tongue is embryologically divided into the anterior and posterior part. The anterior part is known as the oral or presulcal part that includes the root attached to the floor of the oral cavity. While the posterior part is known as pharyngeal or postsulcal part that includes the base forming the ventral wall of oropharynx.
The tongue is made up of three elements:
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, rod-shaped with a nucleus in the centre. The free surface comprises short taste hair. The taste cells help in detecting taste, which dissolves in saliva for proper sensation.
The tongue muscles are voluntary and contain cross-striated muscular fibres.
The tongue consists of small and scattered glands. These glands are of three types:
- Mucous Glands
- Serous Glands
- Lymph Nodes
The lymph nodes are very prominent at the posterior part of the tongue and are known as lingual tonsils.
The glossopharyngeal nerve and the chorda tympanic branch of the facial nerve are responsible for taste sensation. The sensations of pain, touch, temperature are carried by the trigeminal nerve.
Also Read: Mouth and Buccal Cavity
Following are the important tongue functions:
The tongue helps in chewing.
It helps in swallowing food.
The tongue transmits taste signals to the brain and helps in sensing taste.
It is an important organ that facilitates speech.
It secretes mucous and serous fluid which keeps the mouth moist.
Salivary glands comprise three pairs:
It opens on the inner surface of the cheek by the duct of Stensen. It is located opposite the second upper molar tooth.
It opens by Wharton’s duct on the floor of the mouth by the sides of the frenulum of the tongue.
It opens by the ducts of Rivinus on the floor of the mouth by the sides of the frenulum of the tongue.
Also Read: Human Body
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