Oms2 Semester 1 Anatomy Of The Eyes And Ears

Front 1

What are the three concentric layers that form the eyeball?

Back 1

Corneoscleral layer - Fibrous layer - the cornea and sclera

Vascular layer - Uvea - Uveal layer - iris and pupil, ciliary body and aqueous humor (formation, circulation, drainage into the venous system), choroid

Neural layer - Retinal layer - the retina

Front 2

What are some parts of the eye (within it)

Back 2

Eye spaces - anterior and posterior chamber of the vitreous body
Lens and suspensory ligaments
Macula, fovea, foveola, and optic disk

Front 3

List the 5 different neuronal cells.

Back 3

Photoreceptors (cone, rod)
Bipolar cells
Horizontal cells
Amacrine cells
Ganglion cells

Front 4

What structure of the eye is at the center of the origins of the arteries/veins of the eye, visible during a fundoscopic exam?

Back 4

The optic disk

Front 5

What structures of the eye are lateral to the optic disc, and circular and hazy?

Back 5

Macula and fovea centralis

Front 6

What connects the side of the lens to the ciliary processes?

Back 6

Zonular fibers
(suspensory ligament of the lens)

Front 7

What is phototransduction?

Back 7

The process of transferring information about light captured by photoreceptors into electrical signals and sent to higher centers in the brain.

Front 8

Describe the corneoscleral layer of the eye.

Back 8

In the outermost layer of the eye, cornea and sclera. Junction between the sclera and the cornea is the limbus, or corneoscleral junction.

Front 9

Which of the following are vascularized: sclera, cornea, conjunctiva

Back 9

Sclera and Conjunctiva

the cornea is NOT vascularized.

Front 10

Describe the uvea layer of the eye.

Back 10

Middle layer composed of loose connective tissue, highly vascularized and pigmented. Consists of the iris anteriorly, ciliary body, and posterior part is the choroid.

Front 11

Describe the iris.

Back 11

A ring located behind the cornea - contains a stroma of loose connective tissue with numerous pigmented cells (melanocytes) and fibroblasts.

Stroma contains two groups of muscle fibers - radially arranged dilator pupillary muscle and circumferential constrictor or sphincter pupillary muscle.

Front 12

What is the ciliary body?

Back 12

Connected posteriorly to the iris, consists of a wedge-shape dilation of the uvea layer that rings the eye at the level of the lens.

Stroma of the ciliary body contains loose connective tissue, with numerous elastic fibers, blood vessels, and melanocytes.

Contains 3 bundles of smooth muscle

Inner surface is lined by the ciliary epithelium - 2 layers of columnal epithelium.

Front 13

What controls accommodation?

Back 13

Contraction of the 2 smooth muscle bundles in the ciliary body, pulls or relaxes tension on the zonule fibers which connect the ciliary processes to the edge of the lens.

Lens thicker = focuses on closer objects

Front 14

What is the choroid?

Back 14

Posterior part of the uveal layer, it is well vascularized, pigmented - contains melanocytes and fibroblasts.

Front 15

What is the retinal layer?

Back 15

The most inner layer that encircles the eye ball - retinal or neural layer

Anterior to posterior:
Retinal pigmented epithelium
2 layers of Ciliary epithelium
Retina proper

Front 16

Describe the optic disk.

Back 16

The area where retinal ganglion cell axons come together to form the optic nerve. There are no photoreceptors so this region of the eye is also called the blind spot.

Front 17

Describe the macula lutea.

Back 17

Macula lutea - yellow spot - yellowish pigmented area on the retinal wall. The oval depression at the center is the fovea centralis, where all the cone photoreceptors are focused.

Located at the posterior pole of the eye, 2.5mm lateral to the optic disk.

Front 18

What is aqueous humor and how is it produced?

Back 18

Aqueous humor is a protein-poor plasma filtrate produced into the posterior portion of the eye by the inner layer of the ciliary epithelium.

Front 19

How does aqueous humor pass from the posterior chamber to the anterior chamber?

Back 19

Through the pupillary aperture

Front 20

How does aqueous humor leave the anterior chamber?

Back 20

it is reabsorbed in the anterior chamber at the limbus into a set of modified veins, the trabecular meshwork, that leads to the canal of schlemm.

Front 21

Where are the trabecular meshwork and the canal of schlemm?

Back 21

Inside the connective tissue of the sclera at the places around the eye where the iris meets the cornea and the cornea is continuous with the sclera.

Front 22

What condition results from blockage or failure the aqueous humor to leave the eye?

Back 22

Increased pressure on the retinal cells results in damage and glaucoma

Front 23

What is the vitreous body?

Back 23

A transparent, refractory gel composed mostly of water, some electrolytes, collagen fibers, and hyaluronic acid. Some macrophages and small cells (halocytes) can be found in the vitreous body.

They sythesize collagen and hyaluronic acid found in the vitreous body.

Front 24

Describe the lens.

Back 24

Three parts - lens capsule, subcapsular epithelium, and lens fibers or crystallins.

Elasticity decreases with age, resulting in presbyopia

Front 25

Describe the blood supply to the eye.

Back 25

Most blood comes via the central artery of the retina, from the internal carotid - the branches spread on the inner surface of the retina

The outer surface comes from the choroid, which is supplied by the posterior ciliary arteries, which are branches of the ophthalmic artery.

Blood leaves via the superior and inferior ophthalmic veins, and the central vein of the retina - all drain into the cavernous sinus.

Front 26

What muscles and nerves are responsible for light reflex?

Back 26

Constriction of the pupil occurs via the bilateral constriction of the sphincter pupillary or constrictor pupillary muscle which is innervated by parasympathetic fibers of the oculomotor nerve..

Front 27

What muscles and nerves are responsible for accommodation?

Back 27

3 actions - accommodates the lens for near vision, constricts the pupil to focus the light on the desired object, and converges the eyes

Accommodation occurs by constriction of the ciliary muscles in the ciliary body, constriction of the pupil occurs via contraction of the sphincter pupillary muscle, both of which are under control of the parasympathetic fiber in the oculomotor nerve.