Lingual papilla

Lingual papillae (singular papilla) are the small, nipple or hair–like structures on the upper surface of the tongue that give the tongue its characteristic rough texture.

There are four types of lingual papillae on the human tongue: circumvallate papillae (vallate papillae), fungiform papillae, filiform papillae and foliate papillae. All except the filiform papillae are associated with taste buds.

Structure

In living subjects, lingual papillae are more readily seen when the tongue is dry. There are four types of papillae present on the tongue:

Filiform papillae

Filiform papillae are the most numerous of the lingual papillae. Unlike the other kinds of papillae, filiform papillae do not contain taste buds. They cover most of the front two thirds of the tongue's surface.

They appear as very small, conical or cylindrical surface projections, and are arranged in rows which lie parallel to the sulcus terminalis. At the tip of the tongue, these rows become more transverse.

Histologically, they are made up of irregular connective tissue cores with a keratin–containing epithelium which has fine secondary processes. Heavy keratinization of filiform papillae, occurring for instance in cats, gives the tongue a roughness that is characteristic of these animals.