DISSECTION OF THE HEAD AND NECK 



257 



glands (Gl. lacrimales accessoriae) present? Underneath the 

 gland find the minute excretory ducts (ductuli excretorii GL 

 lacrimalis). About how many are there ? Where do they open! 

 Reflect the ligamentum palpebrale mediale and expose the 

 ampulla ductus lacrimalis and the lacrimal sac (saccus lacri- 

 malis}. Note its summit (fornix sacci lacrimalis} and the duct 

 leading from it down into the nose (ductus nasolacrimalis} . 

 (Fig. 108.) 



FIG. 108. 



Papillae lacrimales with the 

 puncta lacrimalia 



Plica semilunaris - -- 

 conjunctivae 



Saccus lacrimalis 



Crista lacrimalis posterior -~ . :; :, : 



M. obliquus inferior -' ' 

 Ductus nasolacrimalis '"' 



Sinus maxillaris "" 



Ampulla ductus lacrimalis 



Lacus lacrimalis (tear lake) 



Fornix sacci lacrimalis 



\---Lig. palpebrale mediale 

 ( turned back ) 



--(Jrista lacrimalis aiitn-inr 



Caruncula lacrimalis 



Mucous membrane of the nasal cavity 

 (laid bare from the outside) 



Lower end of the ductus 

 nasolacrimalis 



The tear sac (saccus lacrimalis), the lacrimal canals (ductus lacrimales), and the nasolaerinwl 

 duct (ductus nasolacrimalis). Part of the maxilla has been removed. (After Toldt, Anat. Atlas, 

 Wien, 1903, 3 Aufl., p. 912, Fig. 1391. ) 



Divide the lids vertically through the middle and turn the 

 medial halves of the lids upward and downward respectively. 

 Dissect away the conjunctiva at the medial angle of the eye and 

 expose the superior tarsal muscle (M. tarsalis superior} and the 

 inferior tarsal muscle (M. tarsalis inferior} (0. T. tensor tarsi). 

 Note the relation of the saccus lacrimalis to the tarsal muscles 

 on one hand and to the medial palpebral ligament on the other. 

 What is the action of the tarsal muscles? 



Nose. 



At this stage the nasal bones (ossa nasalia} and cartilages 

 (cartilagines nasi} may be conveniently examined. Dissect out 

 and study the following: 



(a) Lateral cartilage of nose (cartilago nasi lateral is}. 



(b) Cartilage of septum of nose (cartilago septi misi) (anterior margin ). 



17 



