Henry Gray (1825–1861). Anatomy of the Human Body. 1918.
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inferior directing it upward and lateralward; these movements are required for the correct viewing of an object when the head is moved laterally, as from shoulder to shoulder, in order that the picture may fall in all respects on the same part of the retina of either eye. |
A layer of non-striped muscle, the Orbitalis muscle of H. Müller, may be seen bridging across the inferior orbital fissure. |
FIG. 891– The right eye in sagittal section, showing the fascia bulbi (semidiagrammatic). (Testut.) (See enlarged image) |
The Fascia Bulb (capsule of Ténon) (Fig. 891) is a thin membrane which envelops the bulb of the eye from the optic nerve to the ciliary region, separating it from the orbital fat and forming a socket in which it plays. Its inner surface is smooth, and is separated from the outer surface of the sclera by the periscleral lymph space. This lymph space is continuous with the subdural and subarachnoid cavities, and is traversed by delicate bands of connective tissue which extend between the fascia and the sclera. The fascia is perforated behind by the ciliary vessels and nerves, and fuses with the sheath of the optic nerve and with the sclera around the entrance of the optic nerve. In front it blends with the ocular conjunctiva, and with it is attached to the ciliary region of the eyeball. It is perforated by the tendons of the ocular muscles, and is reflected backward on each as a tubular sheath. The sheath of the Obliquus superior is carried as far as the fibrous pulley of that muscle; that on the Obliquus inferior reaches as far as the floor of the orbit, to which it gives off a slip. The sheaths on the Recti are gradually lost in the perimysium, but they give off important expansions. The expansion from the Rectus superior blends with the tendon of the Levator palpebræ; that of the Rectus inferior is attached to the inferior tarsus. The expansions from the sheaths of the Recti lateralis and medialis are strong, especially that from the latter muscle, and are attached to the lacrimal and zygomatic bones respectively. As they probably check the actions of these two Recti they have been named the medial and lateral check ligaments. Lockwood has described a thickening of the lower part |