8 4 



APPLIED ANATOMY. 



portion is enclosed in a capsule and slung from the orbital margin by its suspensory 

 ligament. Beneath, it rests on the fascial expansion of the levator palpebrae muscle. 

 The palpebral portion is smaller than the orbital and is partially separated from it by 

 the fascial expansion. It lies on the conjunctiva at the upper and outer portion of 

 its fornix. The lachrymal gland opens by several fine ducts into the fornix of 

 the conjunctiva. It is sometimes the seat of malignant tumors, but rarely of other 

 troubles. The remaining lachrymal passages running from the eye to the nose are 

 frequently the seat of inflammation, causing suppuration and obstruction. 



^}\^.puncta lachrymalia in the top of each papilla lead into the canalicidi. These 

 enter the lids perpendicular to their margin and turning at right angles join just 

 before entering the upper end of the lachrymal sac. 



The lachrymal canal, embracing the sac and lachrymonasal duct, each about 

 12 mm. in length, extends from just above the internal tarsal ligament or tendo oculi 

 to the inferior meatus of the nose. The sac is strengthened posteriorly by the tensor 

 tarsi or muscle of Homer, which passes from the lachrymal bone to the puncta, and 

 by some fibres of the palpebral ligament. Anteriorly is the strong palpebral liga- 

 ment. Below the palpebral ligament, the sac is comparatively weak and here it is 

 that distention occurs and pus makes its exit. The duct lies in the lachrymal groove 

 in the bone. It is narrower than the sac, being 3 to 4 mm. in width, and is the usual 



Lachrymal gland 



Canaliculcus 

 Punctum 



Lachrymal sac 



Lachrymonasal duct 



Inferior meatus - 



Inferior turbinate 

 FIG. 98. Lachrymal apparatus. 



seat of obstructions. To keep the passage open in case of stricture probes are 

 passed. The direction of the duct is slightly outward and more markedly backward, 

 being indicated approximately by a line drawn from the inner canthus to just behind 

 the second premolar tooth. In probing the duct it is customary to first open the 

 punctum in the lower lid which is normally only one mm. in size by slitting it and 

 the caniculus with a Weber's canaliculus knife. The probe is directed horizontally 

 until the sac is entered, which is recognized by the end of the probe striking the 

 bone; it is then raised vertically and passed downward and backward and sometimes 

 slightly outward until it can be seen in the inferior meatus of the nose about I cm. 

 behind the anterior end of the inferior turbinated bone. 



THE EAR. 



The external auditory meatus, the tympanum, and the Eustachian tube are the 

 remains of the first branchial cleft in the foetus. A failure of any portion of the cleft 

 to close normally may leave small sinuses or depressions in the neighborhood of the 

 ear. The external ear, also called the auricle or pinna, is composed mainly of a 

 cartilaginous framework covered with thin skin; the lobe or lobule forms its lower 

 part and is composed of dense connective tissue containing fat. The large concav- 

 ity leading into the meatus is the concha. The skin of the ear is thin and moder- 



