Most superficial tunic. What are the 3 layers of the eye? 2022-10-11

A&P 2 Blood Vessels Flashcards

Cross section of the tunica media layer Vasodilation is the opposite of vasoconstriction and is the term used to describe the widening of the blood vessel due to relaxation of the muscular wall. Lamellæ the fibers of which are cut longitudinally. The amacrine cells are placed in the inner part of the inner nuclear layer, and are so named because they have not yet been shown to possess axis-cylinder processes. Corneal corpuscles appearing fusiform in section. In the fetus, a small vessel, the arteria hyaloidea, passes forward as a continuation of the arteria centralis retinæ through the vitreous humor to the posterior surface of the capsule of the lens. In dark eyes many of them contain pigment granules, but in blue eyes and the eyes of albinos they are unpigmented. Venous branches to conjunctiva scleræ.

The Tunics of the Eye

Between this tissue and the anterior surface of the attached margin of the iris is an angular recess, named the iridial angle or filtration angle of the eye Fig. The great saphenous vein ascends through the leg and thigh on the medial side, collecting blood from tissues in these regions. The heart chambers that have just been filled when you hear the first heart sound are the 4 ventricles, and the chambers that have just emptied are the 5 atria. The middle layer called choroid and the inner layer called as retina. Other fibers from the plexus end in a net-work on the anterior surface of the iris. The cones are conical or flask-shaped, their broad ends resting upon the membrana limitans externa, the narrow-pointed extremity being turned to the choroid. It may be regarded as a condensed part of the substantia propria.

What is the longest superficial vein in the body?

What does a pinguecula look like? The Great Saphenous Vein is the longest vein in the body; it runs from inside of the ankle, to the inside of the knee, and up to the groin where it joins the femoral vein saphenofemoral junction. Did you know that your Great Saphenous Vein is the longest vein in the human body? In a meridional section of this region this sinus presents the appearance of a cleft, the outer wall of which consists of the firm tissue of the sclera, while its inner wall is formed by a triangular mass of trabecular tissue Fig. The inner segment resembles the inner segment of the rods in structure, presenting a superficial striated and deep granular part, but differs from it in size and shape, being bulged out laterally and flask-shaped. From the inner extremity of the granule a thick process passes into the outer plexiform layer, and there expands into a pyramidal enlargement or foot plate, from which are given off numerous fine fibrils, that come in contact with the outer processes of the cone bipolars. What holds the eyeball in place? They do not present any cross-striation, but contain a pyriform nucleus, which almost completely fills the cell. The vessels of this membrane are partly derived from those of the margin of the iris and partly from those of the capsule of the lens; they have a looped arrangement, and converge toward each other without anastomosing. Behind it is pierced by the optic nerve, and is continuous through the fibrous sheath of this nerve with the dura mater.

Blood Vessel Layers: Tunica Intima, Tunica Media & Tunica Adventitia

What are the three layers of the eyeball quizlet? This regulation allows for a more efficient exchange of gases and nutrients when blood is within the capillary beds. In the adult the two chambers communicate through the pupil, but in the fetus up to the seventh month they are separated by the membrana pupillaris. The monosyllables describing the heart sounds are 1 lup-dup. Its base is continuous with the inner surface of the sclera immediately to the outer side of the filtration angle and its apex is directed forward and inward. Capillary net-work of the posterior part of the choroid, ending at b, the ora serrata. Most of the fibers are centripetal, and are the direct continuations of the axis-cylinder processes of the cells of the ganglionic layer, but a few of them are centrifugal and ramify in the inner plexiform and inner nuclear layers, where they end in enlarged extremities.

What are the 3 layers of the eye?

In fact, the sclera forms more than 80 percent of the surface area of the eyeball, extending from the cornea all the way to the optic nerve, which exits the back of the eye. Pingueculae do not go away on their own and do not require treatment in most cases. Veins are blood vessels that carry blood towards the heart. Which muscles attach to the sclera? Arterial, and f 1. Your cornea is the transparent layer that lies over your pupil and iris. KOR-oyd A thin layer of tissue that is part of the middle layer of the wall of the eye, between the sclera white outer layer of the eye and the retina the inner layer of nerve tissue at the back of the eye.

Exercises 27, 29

The outer layer contains the sclera the white of the eye and the cornea the clear dome at the front of the eye. From without inward the three tunics are: 1 A fibrous tunic, Fig. Where the optic nerve passes through the sclera, the latter forms a thin cribriform lamina, the lamina cribrosa scleræ; the minute orifices in this lamina serve for the transmission of the nervous filaments, and the fibrous septa dividing them from one another are continuous with the membranous processes which separate the bundles of nerve fibers. Each rod consists of two segments, an outer and inner, of about equal lengths. One bundle, according to Waldeyer, is inserted into the sclera. What is the sclera and its function? The iris is a circular diaphragm behind the cornea, and presents near its center a rounded aperture, the pupil.

What are the 3 layers of the eyeball from superficial to deep? Exactly in the center of the posterior part of the retina, corresponding to the axis of the eye, and at a point in which the sense of vision is most perfect, is an oval yellowish area, the macula lutea; in the macula is a central depression, the fovea centralis Fig. The greater part of the sclera has been removed. The Retina tunica interna. The capillary net-work close to the pupillary margin of the iris. One of these openings, larger than the rest, occupies the center of the lamina; it transmits the central artery and vein of the retina. The former are made up of delicate bundles of fibrous tissue; a few fibers at the circumference of the iris have a circular direction; but the majority radiate toward the pupil, forming by their interlacement, delicate meshes, in which the vessels and nerves are contained.

What are the three layers of the eye? However, the pulmonary vein is the only vein in the body that carries oxygen-rich blood from the lungs back to the heart to be pumped into the rest of the body and the pulmonary artery is the only artery in the body that carries oxygen-poor blood to the lungs to be oxygenated before being sent to the heart to be …. The macula receives two small branches superior and inferior macular arteries from the temporal branches and small twigs directly from the central artery; these do not, however, reach as far as the fovea centralis, which has no bloodvessels. What is the choroid layer? Arteriæ, and I 1. The Ciliary Body corpus ciliare. What is the second layer 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.

The sclera is the white part of the eye that surrounds the cornea. Supporting Frame-work of the Retina. Immediately after the second heart sound, both the 6 atria and 7 ventricles are filling with blood. The smooth muscle found in the tunica media can be stimulated to contract, and this results in vasoconstriction and the narrowing of the blood vessel. Endothelium of the anterior chamber. The stratum opticum or layer of nerve fibers is formed by the expansion of the fibers of the optic nerve; it is thickest near the porus opticus, gradually diminishing toward the ora serrata. SKLAYR-uh The white layer of the eye that covers most of the outside of the eyeball.