Eye - Orbit Flashcards
A = frontal bone
B = zygomatic
C = maxilla
D = lacrimal
E = ethmoid
F = lesser wing of sphenoid
G = greater wing of sphenoid
H = palatine bone
What walls of the orbit are particularly weak?
Medial and inferior walls
Why are the medial and inferior walls of the orbit weak?
Paranasal air sinuses
Name the sinuses in the x-ray
A = frontal
B = ethmoid air cells
C = maxillary sinus
What scan produced this image?
MRI scan
What is the anterior posterior length of the eyeball?
Around 24 mm
What is the anterior posterior length of the orbit?
Around 40 mm
What is the white in this MRI scan?
Orbital fat?
What is the role of orbital fat?
Helps cushion the eyeball and help eyeball sit where it should
What occurs in thyroid eye disease?
Hypertrophy of orbital fat, push eyeball more outwards
When will the eye sink back?
Starvation - hypotrophy
What is the role of the tarsal plate?
Made of dense connective tissue, helps you maintain the shape of the eyeball
What glands are within the tarsal plate?
Meibomian glands
What do the meibomian glads secrete? What is the role of this secretion?
Oily substance
Lines the outside if the tear film and krevents it from evaporating
A-G
What does LPS stand for?
Levator palpebrae superioris
What gland hold the hair follicles?
Sebaceous glands
Where does the connective end?
Where the sclera meets the cornea
What covers the sclera?
Transparent connectiva
Do the blood vessels belong to the conjunctiva or the sclera?
Conjunctiva
What gland is this?
Lacrimal gland
What kinds of secretion is produced by the lacrimal gland?
Watery secretion
What type of innervation stimulates the lacrimal gland?
Parasympathetic from facial nerve
What nerve stimulates the lacrimal gland?
Facial nerve
What do the secretions from the lacrimal gland cover?
The outside of the sclera conjunctiva and cornea
Anterior aspect
Where do the ducts of the lacrimal ducts open onto?
The conjunctival sac
Where does the watery secretion form the lacrimal gland drain?
2 holes associate at the medial corner of the eyelid, connected to 2 rubes called the canaliculi, they go into the sacs… Into the lacrimal sacs
In the medial corners of the eyelid
Where does the lacrimal duct drain into?
Naso-lacrimal duct and open into the nasal cavity below
Into the inferior meat us of the nasal cavity
