Papillae are found on the surface of your tongue. The chief organ of taste, the tongue also helps in chewing and swallowing and plays an essential part in forming the sounds of words. Covered with a mucous membrane, the undersurface of the tongue is smooth, but many papillae (small projections) give the top of the tongue a rough surface. There are four kinds of papillae: Filiform, Fungiform, Foliate and vallate or Circumvallate papillae, which are only found at the back of the tongue and fungiform. The four types of taste buds, found in it, enable us to distinguish between sweet, sour, salty and bitter tastes.

Fact File

THE SENSE OF TASTE IS THE CRUDE OF OUR FIVE SENSES. IT IS LIMITED IN BOTH RANGES AND VERSATILITY. EACH PAPILLA CONTAINS ONE TO TWO HUNDRED TASTE BUDS

What is papilla?

The papilla is a small, nipple-like structure on the surface of the tongue. It is also called the lingual papilla. It gives tongue its rough feel. There are four kinds of papillae on the tongue that have different structures. They are classified below:

1. Filiform papillae

They are fine, small, cone-shaped covering the majority of the tongue. Filiform papillae are responsible for the sensation of touch and providing texture to the tongue. They cover most of the leading two-thirds of the tongue surface, all except that the filiform papillae are associated with flavour buds. They have cylindrical surface projections and are organised in rows which lie parallel to the sulcus terminalis.

2. Fungiform papillae

They are club-shaped projections found on the tip and sides of the tongue. Fungiform papillae are generally red in colour. They have flavour buds in their upper surface which may differentiate the five flavours, i.e., sour, bitter, sweet, salty, and umami. The seventh cranial nerve is innervated them, more especially through the submandibular ganglion, chorda tympani, and geniculate ganglion ascending into the solitary nucleus in the brainstem.

3. Foliate papillae

Foliate papillae are found on each side of the tongue and palatoglossal arch of this fauces. There are five vertical folds, and their dimensions and shape are changeable. It is red in colour and covered with epithelium, deficiency keratin and so are softer, and bear many taste buds. Also, they have usually bilaterally symmetrical. They appear small and inconspicuous, and sometimes they’re prominent. Taste buds and the gustatory sense receptors are scattered over the mucous membrane of their surface. Serous glands clean the taste buds and drain to the folds. Lingual tonsils are located immediately behind the foliate papillae and, even when hyperplastic, cause prominence of the papillae.

4. Circumvallate papillae

They are dome-shaped structures on the human tongue that change in number from 8 to 12. They’re located on the tongue’s surface forming a row the two rows meet in the midline and medially, and run backwards. Each papilla is made up of projection of mucous.