ANATOMY OF THE EYE Flashcards
thin, elastic skin that covers striated and smooth muscles and protects the anterior portion of the eye
Eyelids
what are the Multiple Glands of eyelids?
- sebaceous
- sweat
- and lacrimal
covers the uppermost portion of the iris and is innervated by the oculomotor nerve (CN III)
Upper Lid
What are the triangular spaces formed by the junction of the eyelids known as?
inner or medial canthus and the outer or lateral canthus.
secreted in response to reflex or emotional stimuli
Tears
A healthy tear is composed of three layers what are those three?
- lipoid,
- aqueous,
- and mucoid
the thin transparent mucous membrane provides a barrier to the external environment extending under the eyelids and over the sclera
Conjunctiva
extending under the eyelids is called?
palpebral conjunctiva
over the sclera is called
bulbar conjunctiva
junction of two portions is called?
Fornix
Eyeball - composed of the following three layers
The outer dense fibrous layer, including the sclera and transparent cornea
The middle vascular layer, containing the iris, ciliary body, and choroid
The inner neural layer, including the retina, optic nerve, and visual pathway
The outer dense fibrous layer includes:
sclera and transparent cornea
The middle vascular layer includes:
- iris,
- ciliary body, and
- choroid
The inner neural layer includes:
- retina,
- optic nerve, and
- visual pathway
3 Fluid-containing chambers:
Anterior chamber
Posterior chamber
Vitreous chamber
the largest chamber in the ocular fundus between the lens and retina
Vitreous chamber
transparent, nutrient-containing fluid that fills the anterior and posterior chambers and helps give the eye its shape
Aqueous humor (watery-like)
composed mostly of water and encapsulated by a hyaloid membrane, helps maintain the shape of the eye
Vitreous humor (jelly-like)
When its gel-like characteristics liquefy, stringy debris occurs known as?
floaters
white avascular dense fibrous structure that helps maintain the shape of the eyeball and protects the intraocular contents
Sclera
a vascularized loose elastic tissue that overlies the sclera supplying nutritional support and reacting to inflammation
Episclera
moves the eye around the socket
Extrinsic eye muscles
What are those Extrinsic eye muscles?
- Superior Oblique (inferior and medially)
- Inferior Oblique (superior and medially)
- Superior Rectus (looking up)
- Inferior Rectus (looking down)
- Medial Rectus ( towards nasal area)
- Lateral Rectus (temporal area)
The four rectus muscles and two oblique muscles are innervated by
cranial nerves (CNs) III, IV, and VI
vulnerable transparent avascular domelike structure; forms the most anterior portion of the eyeball and is the main refracting surface of the eye.
Cornea
five layers of cornea
- Epithelium
- Bowman’s membrane
- Stroma
- Descemet’s membrane
- Endothelium
absorbs oxygen and nutrients from the tear film nourishing the cornea
Epithelium
vascular middle layer of the eye consisting of the iris, ciliary body, and the choroid
Uveal tract
highly vascularized pigmented collection of fibers that give the eye color
Iris
The dilator muscles of the iris control pupil size
(SNS)
sphincter muscles of the iris control pupil size
(PNS)
consists of ciliary processes, ciliary muscles, and zonular fibers (ligaments) that work together to form aqueous fluid
Ciliary body
lies between the retina and the sclera, supplying blood and oxygen to the outer retina.
Choroid
avascular and almost completely transparent biconvex structure which enables focusing for near and distance vision through accommodation
Lens
With aging and certain conditions (e.g., diabetes or trauma), the lens loses its transparency and ability to focus due to the formation of a cataract
diabetes or trauma
The fundus’s innermost surface, composed of neural tissue, is an extension of the optic nerve.
Retina
