Ophthalmic and otic memoranda / By D.B.St. John Roosa ... and Edward T. Ely.

  • Ely, Edward T. (Edward Talbot), 1850-1885
Date:
[1885]
Catalogue details

Licence: Public Domain Mark

Credit: Ophthalmic and otic memoranda / By D.B.St. John Roosa ... and Edward T. Ely. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

    60/326 (page 38)
    minute, open in row at outer third upper reflection of conjunctiva. Vessels and nerves enter gland at post, border. Secretion of gland (tears) consists of water, salt and albu- men ; is spread over ant. surface globe, which it lubricates, by winking of lids ; excess col- lects in lacus, and is forced into canaliculi by orbicularis and Horner's muscles, or flows over cheek. [Under ordinary circumstances tears evaporate, scarcely any passing into nose ; and they come mostly from conjunctiva, so that extirpation of lachrymal gland does not materially affect moisture of globe.] Canaliculi [Lat. for little channels} : two mucous canals \-h in. long and about ■£■§ in. diameter, lined by pavement epithelium and enveloped by fibres of Horner's muscle : be- gin at puncta, run nearly horizontally, and open by common or separate orifices into outer wall lachrymal sac behind palpebral ligament. Lachrymal sac: lies in upper end lachrymal canal between border of lach- rymal bone and nasal process sup. maxillary . oval form, flattened antero-posteriorly, about I in. long and ^ in. wide. Larger part lies below level of lower inner angle of orbit. Upper part (fundus) is crossed by tarsal lig- ament, extending about \ in. above it. Tran- sition from sac to duct sometimes direct, sometimes interrupted by folds of mucous membrane. Nasal duct : runs in bony lach • rymal canal, downward, backward, and out-