ANATOMY IX A NUTSHELL. 523 



Action. — To elevate and retract the tongue. 



Nerve Supply. — Hypoglossal. 



Blood Supply. — Facial, lingual and ascending pharyngeal. 



12. Levator palati.— Description. — This muscle, which is long, thick, and 

 rounded, is situated on the outer side of the posterior nares. 



Origin. — From the under surface of the apex of the petrous portioD of the 

 temporal bone, and from the inner surface of the cartilaginous portion of the 

 Eustachian tube. 



[nsertiOn. — Into the posterior surface of the sofl palate where ii blends 

 with the muscle of the opposite side. 



Action. — It elevates the soft palate. 



Nerve Supply. — The spinal accessory through the pharyngeal plexus 

 possibly from the facial through the petrosal branch of the vidian nerve. 



Blood Supply. — Ascending palatine, ascending pharyngeal, descending- 

 palatine, lingual. 



13. Tensor tympani. — Description. — This muscle is situated above the 

 osseous portion of the Eustachian tube in a bony canal. It is separated from 

 the Eustachian tube by the processus cochleariformis. 



Origin. — From the canal it is situated in. under surface of the petrous 

 portion of the temporal bone, and the cartilaginous portion of the Eustachian 

 tube. 



Ixskrtion. — Into the handle of the malleus near its root. 



Action. — To tense the tympanic membrane. 



Nerve Supply. — From the otic ganglion of the fifth nerve. 



Blood Supply. — Tympanic branch of ascending pharyngeal. 



14. Stapedius. — Description. — This is the smallest muscle in the body. 

 Origin. — From the sides of the cavity in the tympanum. Its tendon 



pusses through the foramen in the apex of the pyramid. 



Insertion. — Into the neck of the stapes. 



Action. — To draw the head of the stapes backward and thus rotating it> 

 base inward towards the vestibule, and probably compressing the contents of 

 the vestibule. 



Nerve Supply. — Tympanic branch from the seventh. 



Blood Supply. — Tympanic branch of internal maxillary. 



If). Tensor palati.- Description.- This is a broad triangular muscle with 

 its base upward, and lies at the outer side of the Levator palati. 



Origin.— From scaphoid fossa :it the base of the internal pterygoid plate, 

 spine of sphenoid bone, vaginal process of temporal bone, cartilaginous portion 

 of the Eustachian tube, and hamular process. 



Insertion.- Into the anterior surface of the sofl palate, and the trans- 



verse ridge on the horizontal portion of the palate bone. 



Action.— 11 tenses the soft palate, and opens Eustachian tube during 



deglutition. 



Nerve Supply. Otic ganglion of the fifth nerve. 



Blood Supply. Ascending palatine, ascending pharyngeal, descending 

 palatine, lingual. 



