What is fibrous tunic?
fibrous tunic – The outermost coat of the eyeball consisting of dense collagenous tissue and divided into an anterior transparent cornea and a posterior opaque (white) sclera; this layer provides support, protection and determines the shape of the eye.
What are the components of the fibrous tunic and vascular tunic?
The eye is made up of three layers: the outer layer called the fibrous tunic, which consists of the sclera and the cornea; the middle layer responsible for nourishment, called the vascular tunic, which consists of the iris, the choroid, and the ciliary body; and the inner layer of photoreceptors and neurons called the …
What is the fibrous tunic made up of quizlet?
The delicate fibrous membrane, composed of collagen fibers, which holds the lens of the eye in place; it is anchored to the ciliary process/body.
What type of tissue is each tunic made up of?
The innermost layer, or tunica intima, consists of a lining, a fine network of connective tissue, and a layer of elastic fibres bound together in a membrane pierced with many openings. The tunica media, or middle coat, is made up principally of smooth (involuntary) muscle cells and elastic fibres…
Where is the fibrous tunic located?
Fibrous tunic: The fibrous tunic is the outermost layer of the eye. An opaque (not transparent) network of collagen (fibrous protein) and elastic fibers, called the “sclera,” covers the posterior (back) three fourths of the eye.
What are the three primary functions of the fibrous tunic?
What makes up vascular tunic?
The middle layer of tissue surrounding the eye, also known as the vascular tunic or „uvea“, is formed – from behind forward – by the choroid, the ciliary body, and the iris. The choroid takes up the posterior five-sixths of the bulb and is mainly comprised of blood vessels.
What is the posterior portion of the fibrous tunic called?
The sclera and cornea form the fibrous tunic of the bulb of the eye; the sclera is opaque, and constitutes the posterior five-sixths of the tunic; the cornea is transparent, and forms the anterior sixth. The term “corneosclera” is also used to describe the sclera and cornea together.
What is vascular tunic?
Middle coat (vascular tunic) The middle layer of tissue surrounding the eye, also known as the vascular tunic or „uvea“, is formed – from behind forward – by the choroid, the ciliary body, and the iris. The choroid takes up the posterior five-sixths of the bulb and is mainly comprised of blood vessels.
What layer is thickest in arteries?
The wall of an artery consists of three layers. The innermost layer, the tunica intima (also called tunica interna), is simple squamous epithelium surrounded by a connective tissue basement membrane with elastic fibers. The middle layer, the tunica media, is primarily smooth muscle and is usually the thickest layer.
Which tunic is the retina?
The innermost layer of the eye is the neural tunic, or retina, which contains the nervous tissue responsible for photoreception. The eye is also divided into two cavities: the anterior cavity and the posterior cavity. The anterior cavity is the space between the cornea and lens, including the iris and ciliary body.
What is the name of the outermost white fibrous tunic of the eye?
The outer layer of the eyeball is a tough, white, opaque membrane called the sclera (the white of the eye). The slight bulge in the sclera at the front of the eye is a clear, thin, dome-shaped tissue called the cornea. The middle layer is the choroid.
What are the two parts of the fibrous tunic?
The fibrous tunic of the eye is composed of two parts. what are they? – a nervous tunic, the retina. Rate! Rate! The sclera and cornea form the fibrous tunic of the bulb of the eye; the sclera is opaque, and constitutes the posterior five-sixths of the tunic; the cornea is transparent, and forms the anterior sixth.
What is the difference between a fibrous tunic and a sclera?
Fibrous Tunic. The fibrous tunic is comprised of 2 components, the clear cornea and the opaque sclera . They differ primarily in the arrangement or organization of their collagen and water content with this accounting for the difference in their transparency.
What kind of cells are in the tunics of the eye?
The cells of the deepest layer are columnar; then follow two or three layers of polyhedral cells, the majority of which are prickle cells similar to those found in the stratum mucosum of the cuticle. Lastly, there are three or four layers of squamous cells, with flattened nuclei.
What kind of tissue is the substantia propria made of?
The substantia propria is fibrous, tough, unyielding, and perfectly transparent. It is composed of about sixty flattened lamellæ, superimposed one on another. These lamellæ are made up of bundles of modified connective tissue, the fibers of which are directly continuous with those of the sclera.