The spur is attached anteriorly to the trabecular meshwork and posteriorly to the sclera and the longitudinal portion of the ciliary muscle. It originates near the nose. It allows light to enter the eye. 12. of the cornea. At the front of the eye is the cornea. The average thickness of the bulbar conjuntival membrane is 33 microns. sclera may play a major role in ocular disease and pathology . Along with the…, The ophthalmic artery branches off from a major group of blood vessels in the head and neck known as the internal carotid arteries. It is thickest in the area surrounding the optic nerve. Ultrastructural studies show that developmental events of the sclera begin in the region anterior to the equator at approximately day 43. Best answer. The ophthalmic…, The medial rectus muscle is the largest of the eye’s extraocular movement muscles, six individual muscles that surround the eye and help control the…, The optic chiasm or optic chiasma is an X-shaped space, located in the forebrain, directly in front of the hypothalamus. Ciliary body is a part of eye consisting of ciliary muscles that change the shape of lens. D The colored portion of the eye b. pupil, 3. The muscles that move the eyeball are attached to the sclera. Asked in: Biology - Neural Control and Coordination, 1 Verified Answer | Published on 22nd 08, 2020, 1 Verified Answer | Published on 21st 08, 2020. So, the correct answer is 'Cornea'. In childhood (or in pathological conditions) when the sclera is thin, it appears bluish, while in old age it may become yellowish, due to a deposition of fat. A) sclera B) cornea C) retina D) iris. Sclera. The sclera is thickest posteriorly (about 1 mm) and gradually becomes thinner towards the front of the eyeball. The choroid is a thin membrane lying beneath the sclera, and is connected the posterior section of the ciliary body. It’s connected to muscles that help the eye move. B The opening in the iris through which light passes d. iris, 5. A clear, delicate membrane called the conjunctiva covers the sclera. The transparent anterior portion of the sclera is the iris retina cornea from BIO 101 at Darton State College The aqueous humor is synthesized by the ciliary body. D) choroid. It regulates the amount of light entering the eye by controlling the size of pupil. Its anterior portion is visible and constitutes the 'white' of the eye. B Explanation: A) The sclera is the white of the eye. 6. See a … B) retina. Fibers of the optic nerve pierce the sclera at the optic disc. Iris is a opaque and pigmented structure in eye. The white visible portion of the eyeball. E) pupil. © 2012-2021 by EduZip Technologies Pvt Ltd. All Rights Reserved. While the focus of investigations has mainly been its posterior part to this point [3–5], the scientific community becomes more attracted to the anterior portion because of the popularity of intravitreal injections, the potential role in There are a number of abnormalities associated with the sclera. A series of fibers that connects the ciliary body of the eye with the lens, holding it in place. Skin that covers the upper part of the eyeball, including the cornea, when closed. The transparent anterior portion of sclera is. It is visible as coloured portion. What is the name of the transparent layer of the eye in front of the anterior chamber! The uveal tract is a layer of tissue located between the outer layer (cornea and sclera) and the inner layer (the retina) of the eye. All rights reserved. B) retina. sclera: transparent anterior part of the sclera in front of the aqueous humor and lies over the iris: cornea: middle layer of the eye: choroid: pigmented muscular structure that allows light to pass through: iris: opening in the center of the iris: pupil: lies directly behind the pupil - it focuses and bends light: lens The iris of the eye has two main types of contractile structures. The scleral spur is a fibrous ring that, on meridional section, appears as a wedge projecting from the inner aspect of the anterior sclera (Figs 3-1 and 3-2). Thin, annular structure, colored portion of the eye which helps to regulate the amount of light entering the eye. The Eustachian tube helps in equalising the pressure on either sides of the ear drum. It is the first part of the eye to refract, or bend, light rays. Iris. The anterior one-sixth of the eye is transparent and is called the cornea, and the posterior five-sixths of the eye is opaque and is called the sclera. Part Area Palpebral or tarsal conjunctiva Lines the eyelids Bulbar or ocular conjunctiva Covers the eyeball, over the anterior sclera: This region of the conjunctiva is tightly bound to the underlying sclera by Tenon's capsule and moves with the eyeball movements. Along with the sclera the choroid provides a light-tight environment for the inside of the eye, preventing stray … True The structure that is posterior to the iris and is a colorless structure that allow the eye to … In childhood (or in pathological conditions) when the sclera is thin, it appears bluish, while in old age it may become yellowish, due to a deposition of fat. It is the largest portion of the uveal tract. Upper eyelid. D) pupil. a laser procedure that reshapes the corneal tissue beneath the surface of the cornea to correct astigmatism, hyperopia, and myopia. Located behind the cornea is the pupil, the part of the eye through which light can enter the interior of the eye. LASIK is a combo of Excimer laser and lamellar keratoplasty - differing from PRK in that it reshapes corneal tissue beneath the surface rather that on the surface. It is the only part of human body which is devoid of blood supply and absorbs oxygen directly from the air. 9. The sclera is the part of the eye commonly known as the “white.” It forms the supporting wall of the eyeball, and is continuous with the clear cornea. The _____ is the anterior transparent portion of the eyeball. A tough white covering called the sclera protects the eye. C) cornea. E. Cornea is the anterior portion of sclera which absorbs oxygen from the air. The sclera is made up of three divisions: the episclera, loose connective tissue, immediately beneath the conjunctiva; sclera proper, the dense white tissue that gives the area its color; and the lamina fusca, the innermost zone made up of elastic fibers. The sclera is the part of the eye commonly known as the “white.” It forms the supporting wall of the eyeball, and is continuous with the clear cornea. The junction of the cornea and the sclera is called the limbus. C. Pupil is the aperture of eye through which light rays enter the eye. The junction between the white sclera and the clear cornea is called the limbus.The sclera ranges in thickness from about 0.3 millimeter (mm) to 1.0 mm. The cornea is the most anterior portion, differing from the rest of the sclera in that it is transparent and has no capillaries. It is the only part of human body which is devoid of blood supply and absorbs oxygen directly from the air. 10. It is the second of several pairs…, The orbicularis oculi muscle is one of the two major components that form the core of the eyelid, the other being the tarsal plate. While we can only see the visible portion of the sclera, it actually surrounds the entire eye and provides structure for the internal contents of the eye, which are mostly made up of a thick liquid called the vitreous humor. The choroid is a pigmented and richly vascularized membrane that lines the inner surface of the sclera. Some are genetic and include: There are now state-of-the-art contact lenses that are fitted to treat those with scleral ectasia. Which pair of structures distinguishes a nerve cell from other cells? Healthline Media does not provide medical advice, diagnosis, or treatment. The most anterior portion of the uvea is the iris. Retinal blood vessels also enter and exit the eye at the optic disc. E) choroid. The sclera forms the entire visible white exterior of the eye, the iris is the colored portion inside the anterior chamber of the eye.. Its anterior portion is visible and constitutes the 'white' of the eye. e. Sclera. The conjunctiva extends over the the 'white of the eye', which corresponds to the anterior part of the sclera, folds back and continues over the posterior part of the eyelid. The vascular pigmented structure of the uvea is the choroid. The anterior part of the eye consists of the transparent cornea, which serves as the eye’s “windshield”, allowing us to view the world, and at the same time, protecting the eye from external impacts. The orbicularis…, Combined with the cardiovascular system, the circulatory system helps to fight off disease, helps the body maintain a normal body temperature, and…, Humans are sexual, meaning that both a male and a female are needed to reproduce. Cornea is the anterior portion of sclera which absorbs oxygen from the air. The ciliary body contains the ciliary muscle. The sclera is thickest posteriorly (about 1 mm) and gradually becomes thinner towards the front of the eyeball. The Eustachian tube connects the middle ear cavity with the pharynx. The anterior uvea includes the iris and the ciliary body. The sclera is the "white of the eye". Acquired abnormalities of the sclera include: Episcleritis: a hypersensitivity reaction which can be anterior or posterior, is characterized by engorged blood vessels, and can also affect the cornea, Last medically reviewed on January 19, 2018, The superior oblique is a fusiform (spindle-shaped) muscle belonging to the extraocular group of muscles. The posterior portion of the uvea is the choroid, which is a highly vascular tissue just posterior to the retina. Becomes continuous w/dura mater that surrounds the optic nerve. What is another name for the anterior portion of the sclera? At the opening formed by the eyelids, the conjunctive merges with the skin which covers the anterior surface of the eyelids. The transparent nonvascular structure located on the anterior portion of the sclera is the cornea. How would you define an extrinsic muscle of the eye? It is continuous with the stroma layerstromaThe cornea's middle layer; it consists of lamellae (collagen) and cells, and makes up most of the cornea. The sclera is the tough, opaque outer layer of the eye that provides it with protection and structural integrity. The sclera is the dense connective tissue of the eyeball that forms the \"white\" of the eye. The front portion (anterior) of the uveal tract contains the iris, and the back portion (posterior) of the uveal tract contains the choroid and the stroma of the ciliary body. The middle layer of the eye wall is the vascular tunic, the posterior portion of which is called the choroid. Protects our eyes from dust and infection causing agents. 11. The anterior pigmented portion of the retina is called the ora serrata. The sclera is the protective outer layer of the eye, which is also the white part of the eye. © 2005-2021 Healthline Media a Red Ventures Company. C) iris. The sclera and the cornea make the dense, durable wall that protects the intraocular contents. It is also called the second cranial nerve or cranial nerve II. Vitreous body. It is biconvex in nature and focus the light rays on the retina. The Sclera of the eye is the outermost layer which gives the white colour to the white part of the eye. A Consists of … On the anterior surface of the eye is the transparent cornea, which is continuous with the sclera, a tough, white outer coat of the eyeball that helps maintain the spherical shape of the eyeball. The ciliary muscle is responsible for adjusting the lens. View Full Answer. medical-terminology; 0 Answers. The transparent anterior portion of sclera is Transparent Background. The cornea is the anterior, transparent portion of the outer coat. Crucial to vision, the left…, The optic nerve is located in the back of the eye. Asked in: Biology - Control and Coordination, Read our Copyright Statement For Any Removal or Reproduction. answered Nov 11, 2016 by Nondetta . The transparent anterior portion of the sclera is the A) iris. The sclera transitions anteriorly to become cornea at the limbus and posteriorly into the optic nerve dural sheath (Figures 12 and 13). Space inside the retina and behind the lens is filled with, Which of the following communicates with the central canal and spinal cord. Part of the white sclera can be seen in the front of the eye. Lens of eye is a crystalline structure in the eye ball which is held in place by ligaments that are attached to ciliary body. The transparent central anterior portion of the sclera through which light enters the eye is calld the: A) cornea. The sclera is covered by the conjunctiva, a clear mucus membrane that helps lubricate the eye. asked Nov 11, 2016 in Health & Biomechanics by Tatil. Each is equipped with specific organs capable of producing specific…, The supraspinatus muscle is a rotator cuff muscle located in the shoulder, specifically in the supraspinatus fossa, a concave depression in the rear…, The corpus spongiosum is yet another part of the male anatomy that facilitates sexual reproduction. The iris is the colored part of the eye that contracts and expands so the pupil can let just the right amount of light into the eye… Melanosis: excess deposits of melanin (pigment) on the surface of the sclera, which can become inflamed and uncomfortable, Scleral Coloboma: missing tissue that results in notching and bulging of the sclera (lesions), Ectasia: a thinning and bulging of the sclera, Ectasia that can be brought on as a side effect of traumas or inflammations. Its FREE, you're just one step away. Suspensory ligament of lens. Our website services, content, and products are for informational purposes only. G The iridescent portion of the choroid layer in nocturnal animals e. reina, 6. Answer: b. The cornea is the clear part of the eyes protective covering. Any portion of the uveal tract could become inflamed; adjacent tissue also is frequently inflamed. F This structure changes shape to focus light on the retina c. sclera 4. Bulbar conjunctiva covers the anterior portion of sclera (does not cover cornea), whereas palpebral covers inner surface of both upper and lower eyelids. sclera: The __ provides for eye shape, proteccts the eye's delicate internal components, and serves as attachment site for extrinsic eye muscles. It is a soft, spongy tissue that surrounds the…. 0 votes. What gland produces tears?