Oral cavity. "Tongue."

Tongue

• is almost purely made of muscle
• the ant 2/3 is called the oral part = originates from 1st pharyngeal arch
• post 1/3 = pharyngeal part, orginates from 3rd arch, behind terminal sulcus of tongue
• @ midline of terminal sulcus is foramen cecum, the remnant of thyroglossal duct
• root = from 4th arch
• Has midline sulcus on dosal surface = location of fusion of 1 lateral swellings of ant tongue over tuberculum impar.

Function: aid in speaking, allow for movement of food toward oropharynx and within oral cavity
Parts:
Body – most of the tongue
Apex – pointed ant part
root – part fixed to hyoid bone and mandible, is located behind palatoglossal fold, location of lingual tonsils.
Taste Buds: SEE HISTO
The inferior surface of tongue has a very thin mucus membrane, so can see many veins, and is attached to floor of mouth via another mucus membrane fold = lingual frenulum. – Basically keeps tongue in mouth while allowing apex to move about
Muscle of Tongue = all innervated by CN XII, except palatoglossus, which we already said is innervated by Pharyngeal plexus, via CN X
Intrinsic m - change the shape of tongue itself
Sup/Inf Longitudinal, Transverse, Vertical
Extrinsic m – change position of tongue

• Genioglossus – protrudes and depresses tongue
• Hyoglossus – depresses and retracts tongue
• Styloglossus – retracts and elevate tongue
• Palatoglossus – elevates tongue.

Reference: www.anatomytopics.wordpress.com/2008/12