Eye Anatomy Flashcards
What bones make up each Margin of the Orbit:
- superior
- inferior
- lateral
- medial
Superior- frontal bone
Inferior- zygomatic & maxillary
Lateral- zygomatic process of frontal bone
Medial- maxilla, lacrimal, frontal
What bones make up the walls of the orbit?
- Roof
- posterior lateral wall
- Floor
- Medial Wall
Roof-frontal and sphenoid
Posterior Lateral- zygomatic sphenoid
Floor- maxilla, zygomatic, palantine
Medial- ethmoid, lacrimal, frontal
Structures that enter the optic canal?
- optic nerve
- ophthalmic artery
- central retinal vein
Structures that pass through the superior orbital fissure
- Occulomotor Nerve, Trochlear Nerve, Abducens Nerve
Lacrimal, frontal, and nasocilliary branches of opthalmic nerve
Opthalmic vein
Sympathetic fibers of cavernous plexus
Pneumonic
Live frankly to see absoultely no insult
-lacrimal Frontal Trochlear neve Superior occulomotor Abducens Nasocilliary
Inferior occulomotor
Term that describes upper and lower eyelid
-functions
- palpebrae
- function: protect and lubricate the eyes
What is the tarsal plate?
What is the canthus?
-what are some deformalities of the canthus?
Line that runs through the canthus?
- fibrous layer that gives the lids shape, strength, and place for muscle attachment
- canthus is where upper and lower lids meet, there are two; lateral and medial canthus
- palpebral fissure, ususally runs horizontally.
- upward slant = downs syndrome
- epicanthic fold- covers the medial canthus = chromosome abnormalities. turners, fetal alcohol syndrome
What are meibomian glands? Where are these located?
- these glands lie underneath and within the tarsal plate
- these glands secret oil, secretions enable airtight closure of the lids.
What is a Chalazion?
-back up of fluid/oil from meibomian glands that causes a lump in the eyelid near the eyelashes, they are nontender, non-red, and removed via I&D.
How is a stye different from Chalazion?
Stye= like pimple, red, tender, anywhere on eyelid
Chalazion= lump, non red, non tender, near eyelash line.
Muscles of the Eyelid, function, and Cranial Nerve
Orbicularis oculi- closes the eyelid, CN VII (hook)
Levator Palpebrae- opens the eyelid, CN III (pillars)
Lacrimal glands
- location
- type of secretions
- function of secretion
- where do these secretions drain
- located within eyelid and conjunctive in the superior lateral aspect of eye.
- serous secretions= tears
- tears clean and lubricate eye, antibacterial enzyme lysozyme.
- drain into the lacrimal punctum (little holes near the medial canthus) down into nose near inferior turbinate
Describe the conjunctiva
Describe the borders of the conjunctiva
What are the 2 types of conjunctiva?
- thin mucus membrane with lines with blood vessels, lines inner surface of both eyelids
- starts at the edge of the cornea at the limbus and flows back behind the eye, loops forward, and forms inside the surface of the eyelids.
- Palpebral conjunctiva = lines eyelids
- Ocular conjunctiva= covers eyeball
Name each layer of the eyeball and what comprises each.
- Fibrous Tunic
- —sclera and cornea
- Vascular Tunic
- —choroid, ciliary body, and iris
- Internal or Neural Tunic
- —retina (contain neural retinal layer and outer pigmented layer)
Describe the Sclera
FIBROUS TUNIC
- outer layer of the eyeball
- tough, opaque white fibrous layer
- maintains the shape of the globe
- continuous and connects to the transparent cornea anteriorly»> cornea is clear because the (stuff) is more orgnized
- posteriorly continuous with the dura mater that surrounds the optic nerve
Describe the Cornea
FIBROUS TUNIC
- Convex clear front surface of the eye
- provides majority of eyes refractive power
- avascular, gets nutrients from tears and aqueous fluid as well as peripheral blood vessels
- 5 layers
- -epithelium
- -bowman’s
- -stroma (makes up 90% of cornea, can form a scar)
- -descemets
- -endothelium (regulates fluid that goes into cornea too much liquid can make vision blurry and require a corneal transplant)