Pupils serve as the initial stage in creating a retinal image of an object. As the light passes through the cornea, it bends.A strong, transparent cover (cornea) present protects the iris and pupil of the cow’s eye.There is an aperture in the middle of the iris called a pupil.The stroma is a network that holds a cell-free jelly, the water content of which determines the intraocular pressure.The vitreous humor present is a transparent gel-like substance that enables the seamless passage of light from the aperture to the retina.This posterior cavity is filled with vitreous humor liquid that extends between the lens and the retina.The posterior cavity is the cavity formed between the lens and the retina.The posterior chamber is the space between the lens and the iris. The anterior part is the space between the iris and the cornea.The aqueous humor (a watery liquid) is contained in the space between the lens/suspensory ligaments and the cornea.The internal structures of the cow’s eye comprise the following: Anterior cavity (consists of anterior and posterior chambers) The nasolacrimal duct drains this to the nasolacrimal orifice, which is hidden on the medioventral surface of the alar fold. The upper and lower lacrimal puncta and the lacrimal canaliculi drain into the lacrimal sac. Tears collect in the lacrimal lake in the medial angle anterior to the third eyelid around the lacrimal caruncle. The accessory lacrimal gland of the third eyelid is the largest. The lacrimal ducts connect the apparatus’s ventral end with orifices in the lateral fornix. And a long thin tail that extends around the lateral margin of the orbit. The lacrimal apparatus lies in the dorsolateral quadrant of the orbit, with the broad dorsal part under the root of the zygomatic proc. The deep part of the cartilage is surrounded by the gland of the third eyelid, larger than in the horse, extending about 5 cm straight back into the fat medial to the eyeball and discharging tears through orifices on the bulbar side of the third lid. The third eyelid is made up of a conjunctival fold in the medial angle that encloses the T-shaped outer end of the third eyelid cartilage. The palpebral conjunctiva joins the bulbar conjunctiva at the fornix and ends at the limbus of the cornea. The fibrous part of the middle layer is attached to the osseous orbital margin and increases in density towards the free border to form the tarsus, which contains the tarsal glands. The upper and lower eyelids (palpebra superior and inferior) are made of an outer layer of hair skin, a middle fibromuscular layer, and the palpebral conjunctiva. The eyelids, conjunctiva, lacrimal apparatus, the cone of striated bulbar muscles with their fasciae, and the nerves are all the accessory organs of the eye. The lens changes shape as these muscles are tightened (contraction) or relaxed (relaxation), allowing the eyes to concentrate on close or far things. The lens’ shape can be changed by these external muscles linked to the eye, allowing it to concentrate on objects at different distances. The eyeball’s posterior surface has six muscles connecting it to the cow skull’s bony orbit. It helps the brain to interpret visual images and create mental images. It carries the electrical signals from the retina to the brain. This optic nerve is a bundle of nerve fibers that connects the eye to the brain. The nerve, with a diameter of around 3mm, is placed posteriorly and medially in the eye socket, which works as a mediator for signals. One can clearly distinguish it from the anterior sclera. It is a thin mucous membrane that covers the anterior surface of the eyeball. _ The white of the eye.Ĥ.It helps to protect the inner layers of the eye from damage Conjunctiva _Consists of muscles, which control and shape the lens. _ The iridescent portion of the choroid layer in nocturnal animals. _ The opening in the iris through which light passes. _ This structure changes shape to focus light on the retina. _ Contains the photoreceptors for vision. Match the following parts of the eye to their function: (ciliary body, sclera, iris, retina, lens, & tapetum lucidum) Name the three layers you sliced through when you cut across the top of the eye:Ĥ. Tell three observations you made when you examined the surface of the eye:ģ.
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