Anatomy of the Eye and Visual Pathway

Flashcards based on lecture notes about the anatomy of the eye and visual pathway.

The __ is the organ of vision & principal component of the visual apparatus

Organ of vision and principal component of the visual apparatus.

Coats of the eyeball include __, __ & __.

Fibrous coat, Vascular coat, Nervous coat

Refracting media in the eye include __, __ & __.

Lens, Vitreous & Aqueous humor

The outer layer (fibrous coat) consists of & .

Transparent cornea anteriorly & opaque sclera posteriorly.

The middle layer (vascular coat) includes __, __ & __.

Choroid, ciliary body and iris.

The inner layer (nervous coat) is the __.

Retina

The sclera is __ of the outer coat.

The posterior five-sixths of the outer coat

The sclera consists of dense fibres, interspersed with fibres.

Collagen and elastic fibers

The cornea occupies the __ of the eye.

Anterior one-sixth of the eye

The cornea is completely __.

Avascular

The choroid is a lining the inner surface of the .

Thin, pigmented layer lining the inner surface of the sclera.

Choroid capillaries provide nutrition for the __.

Rods and cones of the retina

The __ consists of smooth muscle and functions to focus the lens for near vision.

Ciliary muscle

The size of the __ controls the amount of light entering the eye

The pupil

At the entrance of the optic nerve is a circular pale area, this is the __.

Optic disc

The macula lutea is a __ at the posterior pole of the eye (lateral to the optic disc).

Shallow depression at the posterior pole of the eye lateral to the optic disc.

In the center of the macula is a shallow pit called the __.

Fovea centralis

Most of the refraction of light takes place at the junction of __.

Air and corneal epithelium

The clear fluid that lies between the space in back of the cornea and the front of the lens is called the __.

Aqueous humor

Aqueous humor is produced by the __.

Ciliary processes

Aqueous humour filters through trabecular tissue into the canal of Schlemm at the __.

Iridocorneal angle

The __ is a series of delicate fibrils attached to the ciliary processes and ciliary body.

Suspensory ligament of the lens (zonule)

The vitreous humor comprises __.

99% water and a sparse cellular and fibrous content

Two groups of muscles of the eye are muscles of eyeball and muscles

Extrinsic and Intrinsic

Ciliary Muscle fibers in the ciliary body are controlled by Parasympathetics from the __.

Oculomotor nerve [III]

The levator palpebrae superioris __.

Elevates the upper eyelid

Nerve supply to Extrinsic muscles of eye: , , __

Lateral rectus - VIth nerve , Superior oblique – IVth nerve , others by the IIIrd nerve

Elevation means __.

Moving the pupil superiorly

Depression means __.

Moving the pupil inferiorly

Medial rectus causes __.

Adduction

The main function of the eyelid is to __.

Protect the surface of the eyeball

Layers of the eyelids are __, __, __, __, & .

Skin, subcutaneous tissue, Voluntary muscle - Orbicularis oculi, Orbital septum, Tarsus, Conjunctiva

The lacrimal apparatus is made up of __, __, & .

Lacrimal gland and its ducts, lacrimal canaliculi, lacrimal sac, nasolacrimal duct

The arterial supply to the structures in the orbit is by the __ artery.

Ophthalmic artery

Two venous channels in the orbit are & .

Superior ophthalmic vein & inferior ophthalmic vein

The visual pathway includes __, __, __, __, __, __ & __.

Retina, Optic nerve, Optic chiasma, Optic tract, Lateral geniculate body, Optic radiation, Visual cortex

The optic chiasma is situated at the __.

Junction of floor and anterior wall of the third ventricle

Few fibers pass to the pretectal nucleus and the superior colliculus of the midbrain and are concerned with __.

Light reflexes

Axons of the nerve cells within the geniculate body leave it to form the __.

Optic radiation

Fibers of the optic radiation terminates in the __.

Visual cortex (area 17)

The visual association cortex (areas 18 and 19) is responsible for __.

Recognition of objects and perception of color

Visual Reflexes includes __, __, __, __, __.

Direct/Consensual Light Reflexes, Accommodation Reflex, Corneal Reflex, Visual Body Reflexes, Pupillary Skin Reflex

Glaucoma: __ of the iridocorneal angle prevents absorption of aqueous humor

Obliteration of the iridocorneal angle prevents absorption of aqueous humour

Trochlear nerve [IV] control the __ muscle

Superior oblique