FACE AND FRONTAL REGION OF HEAD 23 



nerve is a branch of the mandibular division of the trigeminal 

 nerve. It passes forwards into the cheek from under cover 

 of the ramus of the mandible. It is a sensory nerve, and it 

 supplies branches to the skin on the outer surface, and the 

 mucous membrane on the inner surface, of the buccinator 

 muscle. Its communications with the buccal branch of the 

 facial nerve has already been referred to (see p. 20). 



Palpebrae. In the eyelids the following strata will be 

 exposed as the dissection is carried from the surface towards 

 the conjunctiva. 



In addition to the structures enumerated in the above 

 list, two ligamentous bands, named the medial palpebral 

 ligament (O.T. internal tarsal ligament) and the lateral 

 palpebral raphe (O.T. external tarsal ligament), will be 

 noticed. They attach the tarsi to the medial and lateral 

 margins of the orbit. 



Integument and Orbicularis Oculi. Both the skin and 

 the orbicularis oculi have been examined already, and the 

 skin has been reflected. 



Dissection. Separate the palpebral part of the orbicularis 

 oculi from the remainder by a circular incision ; turn the 

 palpebral part towards the rima palpebrarum, and take care, 

 whilst raising the muscle fibres, to preserve the palpebral vessels 

 and nerves, and at the same time to avoid injury to the palpebral 

 fascia. As the dissection is completed the origin of the muscle 

 from the medial palpebral ligament (p. 7) will be displayed. 



Tarsi. The removal of the palpebral part of the orbicularis 

 oculi brings into view the palpebral fascia and the tarsi. 

 They lie in the same morphological plane, and they constitute 

 the ground- work of the eyelids (Fig. 7). 



The tarsi are two thin plates of condensed fibrous tissue, 

 in 2 c 



