MUSCLES OF THE ORBIT 



1069 



tendon into the sclera at the back of the eye. Its nervous supply is derived from the oculomotor 

 nerve. The precise manner of insertion of the different ocular muscles has been described 

 above (p. 1056). For muscles of the eyelids and eyebrows, see pp. 1077 and 1078. 



Action of the ocular muscles. — While rotating the globe so that the cornea is turned in 

 different directions, the ocular muscles do not alter the position of the eyeball in the orbit either 



Fig. 811. — Section through Contents of Right Orbit 8-11 mm. behind the Eteball, 

 VIEWED FROM Behind. (After Lange.) 



Supraorbital nerve 



Supraorbital artery 



Levator palpebrae 



superioris muscle 



Superior rectus 

 muscle 



Superior oblique 

 muscle 



Naso-ciliary 

 nerves 



Medial rectus 

 muscle 



Ophthalmic 

 artery 



Optic nerve 



Ciliary artery 

 Central retinal 

 artery 

 Ciliary artery 



Inferior rectus 

 muscle 



Lacrimal nerve 



Lacrimal vein 



Ophthalmic 

 vein 



^ — Ciliary artery 



Lateral rectus 

 muscle 



Ciliary artery 



Oculomotor nerve 

 — (branch to inferior 

 obhque muscle) 



Fig. 812. — Diagram Representing the Origin of the Muscles at the Apex 



OF THE Right Orbit. 



Lacrimal Frontal Trochlear Levator palpebrae 

 nerve nerve nerve superioris 



Superior oblique 



-Superior rectus 



~— -/ _^ Optic nerve and 



^*~ ophthalmic artery 



Medial rectus 



Inferior rectus 



Lateral Naso- Abducens 

 rectus ciliary 

 nerve 



Oculomotor nerve 



laterally, verticallj^, or antero-posteriorly. In speaking, therefore, of the eye being moved 

 upward or laterally, etc., it is the altered position of the cornea or front of the eye that we mean 

 to express; it is manifest that, if the cornea moves up, the back of the eyeball must simultane- 

 ously be depressed, and similarly with other movements. All the movements of the globe take 



