ANATOMY IN A NUTSHELL. 553 



2. The ethmoidal fissure through which passes the nasal nerve and the 

 anterior ethmoidal vessels. 



3. Olfactory foramina for the olfactory nerves and nasal branches of the 

 ethmoidal arteries. 



4. Anterior ethmoidal foramen for anterior ethmoidal vessels and nasal 

 nerve. 



5. Posterior ethmoidal foramen for posterior ethmoidal vessels and a branch 

 of the nasal nerve. 



6. Optic foramen for the opticnerve and the ophthalmic artery. Thisfor- 

 amen is sometimes given as belonging to the middle fossa since it is <>n the 

 boundary line between the anterior and middle fossa. Thus we can see that 

 there are eleven sets of foramina in the anterior fossa ; five pairs and a single one. 



LESSON CLXXX1X. 

 The middle fossa is on a lower level than the interior fossa wn 



HAS THE FOLLOWING FORAMINA ALL OF WHICH ARE IN PAIRS: 



1. Sphenoidal fissure (anterior lacerated foramen) winch transmits the 

 third nerve, the fourth nerve, and three divisions of the ophthalmic division 

 of the fifth nerve, and the sixth nerve, also filaments from the cavernous plexus. 

 ophthalmic vein, recurrent branch from the lachrymal artery, orbital branch 

 of the middle meningeal artery, and a process of the dura mater. 



2. Foramen rotundum through which passes the superior maxillary divi- 

 sion of the fifth nerve. 



3. Foramen Vesalii which is for a small vein. 



4. Foramen ovale through which passes the inferior maxillary division of 

 the fifth nerve, small petrosal nerve, and the small meningeal artery. 



5. Foramen spinosum through which passes the middle meningeal artery, 

 meningeal veins, and filaments from the cavernous plexus. 



6. Foramen laeerum medium through which passes the vidian nerve, a 

 branch from the ascending pharyngeal artery, carotid artery, and carotid plexus. 



7. Hiatus Fallopii through which passes the petrosal branch of the vidian 

 nerve and the petrosal branch of the middle meningeal artery. 



8. A small foramen through which passes the lesser petrosal nerve. Thus 

 we see there are sixteen sets of foramina in the middle fossa. 



The posterior FOSSA is ox a deeper level than either of the other 



FOSSAE AND CONTAINS THE CEREBELLUM AND THE MIDDLE FOSSA CONTAINS 

 TEMPORO-SPHENOIDAL LOBES OF THECEREBRUM AND THE INTERIOR FOSSA CON- 

 TAINS THE FRONTAL LOBES OF THE CEREBRUM. THIS FOSSA HAS THE FOLLOW- 

 ING foramina: 



1. The meatus auditorius interims for the facial and auditory nerves and 

 the auditory artery. 



2. The aqueductus vestibuli is for a small artery and vein and pri 

 the dura mater. 



3. The jugular foramen (foramen laeerum posterius) in which there are 

 three compartments, through the anterior one of which passes the inferior 



