Long posterior ciliary arteries
Encyclopedia
The long posterior ciliary arteries are arteries of the head arising, together with the other ciliary arteries
, from the ophtalmic artery. There are two in each eye.
at some little distance from the optic nerve
, and run forward, along either side of the eyeball, between the sclera and choroid
, to the ciliary muscle
, where they divide into two branches.
These form an arterial circle, the circulus arteriosus major
, around the circumference of the iris, from which numerous converging branches run, in the substance of the iris, to its pupillary margin, where they form a second (incomplete) arterial circle, the circulus arteriosus minor.
, ciliary body
and choroid
.
Ciliary arteries
The ciliary arteries are divisible into three groups, the long posterior, short posterior, and the anterior.* The short posterior ciliary arteries from six to twelve in number, arise from the ophthalmic as it crosses the optic nerve....
, from the ophtalmic artery. There are two in each eye.
Course
They pierce the posterior part of the scleraSclera
The sclera , also known as the white or white of the eye, is the opaque , fibrous, protective, outer layer of the eye containing collagen and elastic fiber. In the development of the embryo, the sclera is derived from the neural crest...
at some little distance from the optic nerve
Optic nerve
The optic nerve, also called cranial nerve 2, transmits visual information from the retina to the brain. Derived from the embryonic retinal ganglion cell, a diverticulum located in the diencephalon, the optic nerve doesn't regenerate after transection.-Anatomy:The optic nerve is the second of...
, and run forward, along either side of the eyeball, between the sclera and choroid
Choroid
The choroid, also known as the choroidea or choroid coat, is the vascular layer of the eye, containing connective tissue, and lying between the retina and the sclera. The human choroid is thickest at the far extreme rear of the eye , while in the outlying areas it narrows to 0.1 mm...
, to the ciliary muscle
Ciliary muscle
The ciliary muscle is a ring of striated smooth muscle in the eye's middle layer that controls accommodation for viewing objects at varying distances and regulates the flow of aqueous humour into Schlemm's canal. It changes the shape of the lens within the eye not the size of the pupil which is...
, where they divide into two branches.
These form an arterial circle, the circulus arteriosus major
Circulus arteriosus major
circulus arteriosus major : also named "major circulus arteriosus of iris" CIA or CIAMit is formed by anastomosis of the anterior ciliary arteries with the posterior long ciliary arteries at the ciliary body. It supplies the iris, ciliary body and choroid.The veinous drainage of CIA is : 4 vortex...
, around the circumference of the iris, from which numerous converging branches run, in the substance of the iris, to its pupillary margin, where they form a second (incomplete) arterial circle, the circulus arteriosus minor.
Target
The long posterior ciliary arteries supply the irisIris (anatomy)
The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...
, ciliary body
Ciliary body
The ciliary body is the circumferential tissue inside the eye composed of the ciliary muscle and ciliary processes. It is triangular in horizontal section and is coated by a double layer, the ciliary epithelium. This epithelium produces the aqueous humor. The inner layer is transparent and covers...
and choroid
Choroid
The choroid, also known as the choroidea or choroid coat, is the vascular layer of the eye, containing connective tissue, and lying between the retina and the sclera. The human choroid is thickest at the far extreme rear of the eye , while in the outlying areas it narrows to 0.1 mm...
.