Practical anatomy: a manual of dissections / by Christopher Heath.

  • Christopher Heath
Date:
1870
Catalogue details

Licence: Public Domain Mark

Credit: Practical anatomy: a manual of dissections / by Christopher Heath. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    Between the anterior margin of the sclerotic and the ciliary bod}' is a minute canal, which runs round the entire circumference of the eye and is called the Canal of Fon- tana [or of Schlemm or the circular sinus] (Fig. 246, c s). Fig. 247. Anterior Half of the Eye, seen from within (from Wilson). 1. Divided edge of the three coats ; scle- rotic, choroid (the dark layer), aad retina. 2. Pupil. 3. Posterior surface of the iris. 4. Ciliary processes. 5. The anterior border of the retina (ora serrata). [The lens may be observed on either of the eyes thus far used. By tearing its capsule transversely, by a tenaculum, the lens will escape, and the retina, retinal vessels, and optic nerve entrance may be well seen on looking through the vitreous humor. Seize the capsule by the forceps, and such is its strength that the entire eye can be lifted by it. The posterior layer of the capsule can also be well shown by pressure by the knife handle.] The Lens (Fig. 243, 4, 246, L), is situated in front of the vitreous humor, and is contained in a delicate and per- fectly transparent capsule, which is united behind with the hyaloid membrane of the vitreous humor. The capsule is kept in its place by the susioensory ligaments of the lens. [The hyaloid membrane (Fig. 246, h) as it runs forwards splits into two layers, one going in front of the lens (z) and the other behind it. Sometimes the suspensory liga- ment of the lens is defined as the anterior layer only; sometimes, as both layers. On the anterior layer lie the ciliary processes, and the ring of plaitings caused by them has been seen to be the zone of Zinn.] 46