o            Foliate (leaf shaped)         

o            Vallate (ringed shaped)   

    * Sulcus terminalis   

    * Tonsils:  They are present at the back of the tongue. There are two types of tongue,         

o            Lingual tonsils         

o            Palatine tonsils   

   * Adenoids   

   * Frenulum linguae:  It is present on the under surface of the tongue.

Function of each Part of the Tongue

    * Papillae: Papillae contains taste bud (chemo-receptors), which helps us identifybetween different tastes of food.  When we chew food, a portion of it dissolves in thesaliva. This dissolved part of food comes in contact with the taste buds and generates nerve impulses. These nerve fibres are known as microvilli.  These nerve fibres carry messages to the taste center in the brain. Then brain perceives the taste.         

o Foliate, Vallate and Fungiform have taste buds which helps in identifying thetaste         

o Filiform helps in holding the food ( to grip the food in place)   

* Tonsils:  Both the types of tonsils helps in filtering germs.   

* Adenoids: They help in fighting infections.   

* Frenulum linguae: It secures or holds the tongue in place inside the mouth.   

* Very small fibre-like or hair-like projections are present on the upper side of the tongue which connect with nerve fibres at the lower end of the tongue which lead to the brain.