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

  • Heath, Christopher, 1835-1905.
Date:
1885
Catalogue details

Licence: Public Domain Mark

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

    629/682 (page 537)
    (circle of Zinn). The ciliary processes and iris are now seen from behind. If the lens and vitreous hnmonr be drawn out of the fundus of an eye and left attached to the ciliary processes, a magnified view of these will be obtained.] The Ciliary Body (Fig. 270, 7) is the thickened portion of the choroid from which the Ciliary Processes (Fig. 272, 4) project to- wards the centre of the eye. These are vascular fringes which resemble a series of plaits in appearance, and which form a circular curtain parallel but posterior to the iris, from which they are separated by the posterior chamber. They fit into a corresponding series of grooves in the hyaloid membrane of the vitreous humour and together constitute the ciliary zone. Between the anterior margin of the sclerotic and the ciliary body is a minute canal, which runs round the entire circumfer- ence of the eye and is called the Canal of Fontana (Fig. 270, 5). [The lens will be seen on the posterior half of this section, or may be shown on the first eye by carefully removing the iris.] The Lens (Fig. 270, 4) is si- tuated in front of the vitreous humour, and is contained in a delicate and perfectly transparent capsule, which is united behind with the hyaloid membrane of the vitreous humour. The capsule is kept in its place by the suspensory ligament of the lens, a transparent membrane which passes from the ciliary processes to the capsule in front of the hyaloid membrane. By tearing through the capsule (as in the operation for extraction of cataract), its existence will be demonstrated and the lens itself allowed to escape. The lens is bi-convex, but , the posterior surface has a greater curve than the anterior. It is perfectly transparent in health, but has a Fig. 272.—Anterior half of the eye, seen from within (from AYilson). 1. Divided edge of the three coats; 3. Posterior surface of the iris. sclerotic, choroid (the dark 4. Cihary processes. layer), and retina. 5. The anterior border of the retina 2. Pupil. (ora serrata).