What are the parts of the uveal tract?
the vascular, pigmentary, or middle coat of the eye, comprising the choroid, ciliary body, and iris. The pigmented membrane that lines the back of the retina of the eye and extends forward to include the iris. The uveal tract is sometimes called the uvea and has three parts: the iris, the choroid, and the ciliary body.
What is the uveal tract of the eye?
Uveal tract. The pigmented membrane that lines the of the retina of the eye and extends forward to include the iris. The uveal tract is sometimes called the uvea and has three parts: the iris, the choroid, and the ciliary body. Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
What is the uveal and urinary tract?
urinary tract the organs and passageways concerned in the production and excretion of urine from the kidneys to the urinary meatus; see also urinary system. uveal tract the vascular tunic of the eye, comprising the choroid, ciliary body, and iris.
What is the uveal membrane?
The pigmented membrane that lines the back of the retina of the eye and extends forward to include the iris. The uveal tract is sometimes called the uvea and has three parts: the iris, the choroid, and the ciliary body. Gale Encyclopedia of Medicine.
What is the function of uvea?
The uvea is the middle layer of the eye. It lies beneath the white part of the eye (the sclera). It is made of the iris, ciliary body, and choroid. These structures control many eye functions, including adjusting to different levels of light or distances of objects.
Why is it called the uvea?
The middle coat of the eye is called the uvea (from the Latin for “grape”) because the eye looks like a reddish-blue grape when the outer coat has been dissected away.
What are the parts of uvea?
It has three parts: (1) the iris, which is the colored part of the eye;(2) the ciliary body, which is the structure in the eye that secretes the transparent liquid within the eye; and (3) the choroid, which is the layer of blood vessels and connective tissue between the sclera and the retina.
What does uveal mean?
Listen to pronunciation. (YOO-vee-ul MEH-luh-NOH-muh) A rare cancer that begins in the cells that make the dark-colored pigment, called melanin, in the uvea or uveal tract of the eye. The uvea is the middle layer of the wall of the eye and includes the iris, the ciliary body, and the choroid.
What is the blood supply for the uveal tract?
The blood supply of the uveal tract is mainly from three arteries namely short posterior ciliary arteries, long posterior ciliary arteries, and anterior ciliary arteries.
Which area has no vision or sight?
The blind spot is the location on the retina known as the optic disk where the optic nerve fiber exit the back of the eye.
What is uvea in the eye?
The uvea is the middle layer of tissue in the wall of the eye. It consists of the iris, the ciliary body and the choroid. When you look at your eye in the mirror, you will see the white part of the eye (sclera) and the colored part of the eye (iris). The iris is located inside the front of the eye.
What causes uveitis?
Uveitis happens when the eye becomes red and swollen (inflamed). Inflammation is the body's response to illness or infection. Most cases of uveitis are linked to a problem with the immune system (the body's defence against infection and illness). Rarely, uveitis may happen without the eye becoming red or swollen.
Is uvea a word?
Yes, uvea is in the scrabble dictionary.
What is the plural of uvea?
The uvea (plural: uveas), also called the uveal layer or vascular tunic is the middle of the three layers that make up the eye.
What is the white part of your eye called?
The white layer of the eye that covers most of the outside of the eyeball. Anatomy of the eye, showing the outside and inside of the eye including the eyelid, pupil, sclera, iris, cornea, lens, ciliary body, retina, choroid, vitreous humor, and optic nerve.
Where is uvea in the eye?
The middle layer of the wall of the eye.
What is the uveal tract?
Uveal tract. The pigmented membrane that lines the back of the retina of the eye and extends forward to include the iris. The uveal tract is sometimes called the uvea and has three parts: the iris, the choroid, and the ciliary body. Gale Encyclopedia of Medicine.
What is a tract?
tract. [ trakt] a longitudinal assemblage of tissues or organs, especially a number of anatomic structures arranged in series and serving a common function, such as the gastrointestinal or urinary tract; also used in reference to a bundle (or fasciculus) of nerve fibers having a common origin, function, and termination within ...
What is the vascular tunic of the eye?
The vascular tunic of the eye, consisting of the choroid, ciliary body and the iris. The last two structures are usually considered to form the anterior uvea. The uvea contains most of the blood supply (Fig. U2). Syn. uveal tract; vascular tunic of the eye. See uveitis; vortex vein.
Which tissue is responsible for the healing of the sclera?
It is known that the healing of the sclera depends, excessively, on vascularized adjacent tissue, as the episclera and the uveal tract (DUKE-ELDER & LEIGH, 1977).
Where do ocular melanomas come from?
Ocular melanomas usually arise from the uveal tract and initially form an intra-ocular mass. A sinonasal mass in a 79-year-old African American woman. (Pathologic Quiz Case) Diffuse malignant melanoma of the uveal tract: a clinicopathologic report of 54 cases.
What is the gastrointestinal tract?
gastrointestinal tract the stomach and intestine in continuity; see also digestive system.
Where do corticospinal tracts originate?
corticospinal t's two groups of nerve fibers (the anterior and lateral corticospinal tracts) that originate in the cerebral cortex and run through the spinal cord. digestive tract alimentary canal. dorsolateral tract a group of nerve fibers in the lateral funiculus of the spinal cord dorsal to the posterior column.
Which part of the uvea is perforated by the pupil?
The iris, which is the colorful muscular portion of the uvea that is perforated by the pupil.
What does uvea mean in science?
And here is where our grapes come in. Uvea is a term that comes from the Latin for grape, uva. In living tissue, this middle membrane has a reddish-blue color to it, like that of a grape. However, if you were to take an eyeball preserved in formalin and cut it apart so only the uvea remains, it looks blacker in color but still has the appearance of a grape in its size and texture. Cool, huh?
How many parts does the Uvea have?
The uvea consists of three main parts:
What is the vascular tunic of the eye?
The uveal tract, or simply uvea, is the pigmented middle membrane of the layers that make up the eye. The uveal tract is also called the vascular tunic of the eye because it is rich in its blood supply - i.e., vascular - and because it envelops the eye like a tunic would cover a body. So, to recap, the uvea is pigmented and has a nice supply of blood vessels.
Where does the uveal tissue come from?
Embryologically, most of the uveal tissue develops from neural crest cells. 2 The uveal vasculature develops as early as the optic vesicle stage with the formation of a large plexus of primitive vessels that originate from the neural tube vascular system and extend around the outer layer of the optic cup. 3 Its blood supply comes from the ophthalmic artery; vascular and nerve supply are present both anteriorly via the anterior ciliary vessels and nerves ( Fig. 1) and posteriorly via the posterior ciliary nerves and vessels ( Fig. 2 ). A complex arrangement of smooth muscle is part of the anterior and central portions of the uvea, controlling pupillary size and accommodation, respectively.
What is the root of the Uva?
Dimple Modi. Deepak P. Edward. The uvea is derived from the Latin root, uva, meaning grape. The uveal tract consists of a pigmented, highly vascular loose fibrous tissue that can be divided into three anatomical regions: anterior iris, central ciliary body, and the posterior choroid. 1 The uveal tract is firmly adherent to ...
Where are Schwalbe's furrows located?
The iris musculature is derived from the outer lamina of the optic cup and the pigment epithelium from the inner optic cup (neuroepithelium). Therefore, the posterior iris, where Schwalbe’s furrows are located, is formed from the anterior portion of the primitive optic cup.
What is the iris?
General Anatomy 1. The iris is the most anterior portion of the uveal tract. It divides the anterior segment of the eye into the anterior and posterior chambers and is bathed by aqueous on both sides. The iris is a continuous structure but histologically can be divided into multiple layers as discussed below.
What is the uveal tract?
The uveal tract is a vascular intraocular coat composed of the iris, the ciliary body, and the choroid. The iris and ciliary body are located anterior to the ora serrata, the site that marks the beginning of the retina. The ciliary body is contiguous with the iris anteriorly and the choroid posteriorly. It can be divided into an anterior ring, or the pars plicata, and a posterior ring, or the pars plana. The vascular layer of the ciliary body is located between its muscle layer and the two layers of ciliary epithelium. The choroid is the largest and most posterior portion of the uvea, located between the retinal pigment epithelium and the sclera and extending from the ora serrata to the optic nerve. It consists mainly of blood vessels, nerve fibers, and pigmented melanocytic cells in a loose connective tissue matrix (Figure 35 ). The choroid's prime function is to nourish the outer half of the retina. It is supplied by branches of the posterior and anterior ciliary vessels derived from the ophthalmic artery and drained by tributaries of the four or more vortex veins into the orbital ophthalmic veins and through the superior orbital fissure into the cavernous sinus.
What is the UVEA?
The uvea is the pigmented, middle layer of the eye. The uvea may become infected and given its location, particularly when the choroid is involved, ...
What are the components of the UVEA?
Gross Anatomy. The uvea consists of three components: iris, ciliary body, and choroid. The iris is a ring of tissue with a central opening forming the pupil; it separates the anterior and posterior chambers. The outer edge of the iris, known as the iris root, inserts into the ciliary body.
What is the most common cause of anterior uveitis?
The most common infectious cause of anterior uveitis is herpes simplex infection , followed by leprosy, and Lyme’s disease.
What is the iris?
The iris is a circular, extremely thin diaphragm separating the anterior or aqueous compartment of the eye into anterior and posterior chambers. 1. The iris can be subdivided from pupil to ciliary body into three zones—pupillary, mid, and root—and from anterior to posterior into four zones—anterior border layer, stroma (the bulk of the iris), ...
Which part of the uveal tract is analogous to the vascular pia-arachnoid of?
The uveal tract is analogous to the vascular pia-arachnoid of the brain and optic nerve, with which it anastomoses at the optic nerve head.
Which part of the uvea extends from the ora serrata to the optic nerve?
C. The largest part of the uvea, the choroid, extends from the ora serrata to the optic nerve. 1. The choroid nourishes the outer half of the retina through its choriocapillaris and acts as a conduit for major arteries, veins, and nerves. 2.
What are the functions of the uveal region?
In addition, some uveal regions have special functions of great importance, including secretion of the aqueous humour by the ciliary processes, control of accommodation (focus) by the ciliary body, and optimisation of retinal illumination by the iris's control over the pupil.
What is the UVEA prone to?
The normal uvea consists of immune competent cells, particularly lymphocytes, and is prone to respond to inflammation by developing lymphocytic infiltrates. A rare disease called sympathetic ophthalmia may represent 'cross-reaction' between the uveal and retinal antigens (i.e., the body's inability to distinguish between them, with resulting misdirected inflammatory reactions).
What are the constituents of the UVEA?
The constituents of the uvea follow: iris labeled at top, ciliary body labeled at upper right, and choroid labeled at center right. ) The uvea ( / ˈjuːviə /; Lat. uva, "grape"), also called the uveal layer, uveal coat, uveal tract, vascular tunic or vascular layer is the pigmented middle of the three concentric layers that make up an eye.
What is the vascular layer of the eye called?
The uvea ( / ˈjuːviə /; Lat. uva, "grape"), also called the uveal layer, uveal coat, uveal tract, vascular tunic or vascular layer is the pigmented middle of the three concentric layers that make up an eye.
How does the UVEA improve the contrast of the retina?
Light absorption: the uvea improves the contrast of the retinal image by reducing reflected light within the eye (analogous to the black paint inside a camera), and also absorbs outside light transmitted through the sclera, which is not fully opaque.
What is the vascular middle layer of the eye?
The uvea is the vascular middle layer of the eye. It is traditionally divided into three areas, from front to back, the: