FACE AND FRONTAL REGION OF HEAD 137 



border of the upper tarsus; and an inferior lamella, which 

 gains insertion into the upper fornix of the conjunctiva. It 

 raises the upper eyelid by pulling on the upper tarsus, and at 

 the same time elevates the upper fornix of the conjunctiva. 



Vessels and Nerves of the Eyelids. At the medial com- 

 missure two arteries, the palpebral branches of the ophthalmic, 

 pierce the palpebral fascia and run laterally, one in the upper 

 and one in the lower lid. At the lateral margin of the 

 orbit, one or more branches of the lacrimal division of the 

 ophthalmic pierce the palpebral fascia and anastomose with 



Frontal bone 



M. orbicularis oculi 



Palpebral fascia 



Superior conjunctival fornix 

 Superior tarsus 



Conjunctival recess 



Inferior conjunctival fornix 

 Palpebral fascia. 

 FIG. 63. Diagram of the Structure of the Eyelids. 



the palpebral arteries. An arterial arch, circus tarseus, is thus 

 formed close to the margin of each eyelid, between the 

 orbicularis muscle and the tarsus. 



The veins run medially towards the root of the nose and 

 open into the frontal and angular veins. 



The nerves are more numerous and come from a number 

 of different sources. The motor filaments for the various 

 parts of the orbicularis oculi are derived from the temporal, 

 and zygomatic branches of the facial nerve. They enter 

 from the lateral margins. The sensory twigs for the upper 

 lid come from the lacrimal, supra-orbital, supra-trochlear, and 

 infra-trochlear branches of the first or ophthalmic division of 

 the trigeminal nerve; and the lower lid is supplied by the 



