Vascular Tunic
- Iris. The iris is the anterior most portion of the vascular tunic and functions as a moveable diaphragm between the anterior and posterior chambers.
- Ciliary Body. The ciliary body, like the iris, contains both neurectodermal and mesodermal tissue. ...
- Choroid. The choroid is the third component of the uvea. ...
What is the vascular tunic?
The vascular tunic is mesodermal in origin and is situated between the outer fibrous tunic and the inner nervous tunic. The vascular tunic is also refered to as the uvea. The iris is the anterior most portion of the vascular tunic and functions as a moveable diaphragm between the anterior and posterior chambers.
What is the anterior segment of the vascular tunic?
VASCULAR TUNIC FUNCTIONS. The choroid is also continuous with the anterior segment of the vascular tunic, which is known as the iris of the eye. From an external view of the eye, this is the colored portion. Smooth muscles which lie in a continuous, radial, but circular pattern make up the iris.
What is the meaning of vascular tissue?
Of, characterized by, or containing cells or vessels that carry or circulate fluids, such as blood, lymph, or sap, through the body of an animal or plant: vascular tissue; vascular disease. vas′cu·lar′i·ty (-lăr′ĭ-tē) n. The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company.
What structures are on each tunic?
These tunics are :The fibrous tunic : The fibrous tunic is composed of the cornea and sclera.The vascular tunic : The vascular tunic is composed of the iris, ciliary body and choroid.The nervous tunic : The nervous tunic is composed of the retina.
What are the parts of the nervous tunic?
Nervous TunicRetinal pigment epithelium (RPE)Photoreceptor outer segments – Rods and Cones.Outer limiting membrane.Outer nuclear layer.Outer plexiform layer.Inner nuclear layer.Inner plexiform layer.Ganglion cell layer.More items...
What are the two parts of the first tunic?
From without inward the three tunics are: (1) A fibrous tunic, (Fig. 869) consisting of the sclera behind and the cornea in front; (2) a vascular pigmented tunic, comprising, from behind forward, the choroid, ciliary body, and iris; and (3) a nervous tunic, the retina. The Fibrous Tunic (tunica fibrosa oculi).
What are the 3 tunics of the eye?
Answer and Explanation: Fibrous tunic. Vascular tunic. Nervous tunic.
Which tunic contains the retina?
neural tunicThe innermost layer of the eye is the neural tunic, or retina, which contains the nervous tissue responsible for photoreception.
Which structures are part of the vascular layer of the eyeball?
The vascular layer, also known as the uvea or uveal tract. It consists of three parts that are continuous with each other. From posterior to anterior, they are the choroid, ciliary body, and iris. The nervous layer, also known as the retina, which is the innermost layer of the eyeball.
What tunic contains the rods and cones?
nervous tunicWithin the nervous tunic, photoreceptor cells (rods and cones) form synapses with other nerve cells (refer to Figure 1).
What are the three tunics of the eye quizlet?
What are the three layers of the eye? The sclera, the choroid layer, and the retina.
VASCULAR TUNIC ANATOMY
The vascular tunic of the eyeball is also referred to as the uvea. It is comprised of the iris, the choroid, and the ciliary body. The choroid, which is highly vascular, nearly immeasurably thin, and lines nearly the entire surface of the sclera, is designed to prevent the light rays from bouncing right back out of the eyeball.
VASCULAR TUNIC STRUCTURE
The anterior segment of the choroid thickens to create an internal muscular ring toward the front of the eyeball. This muscular ring is known as the ciliary body. The ciliary muscles are naturally found inside the ciliary body, and are created by smooth muscle fiber bands.
VASCULAR TUNIC DIAGRAM
The lens shape is the determining factor at which angle the incoming rays of light are refracted. The lens becomes flatter when the ciliary muscle relax, which causes a greater tension on the suspensory ligament. When the ciliary muscles contract, the ligament then relaxes and the lens becomes a bit more spherical.
VASCULAR TUNIC FUNCTIONS
The choroid is also continuous with the anterior segment of the vascular tunic, which is known as the iris of the eye. From an external view of the eye, this is the colored portion. Smooth muscles which lie in a continuous, radial, but circular pattern make up the iris.
