Week 3 - Wet Room Flashcards
Name the 7 bones making up the orbit
Lacrimal Bone Ethmoidal bone Frontal bone Sphenoid bone (greater wing + lesser wing) Zygomatic bone Maxillary bone
What passes through the optic foramen?
Optic nerve
Ophthalmic artery
What passes through the Superior Orbital Fissure?
Motor nerves of eye:
- III nerve (occulomotor)
- IV nerve (trochlear)
- VI nerve (abducens)
Opthalmic division of V nerve
Ophthalmic veins
What passes through the Inferior Orbital Fissure?
Maxillary division of V nerve
What paranasal air sinuses are in close proximity to the walls of the orbit?
Frontal sinus
Ethmoidal sinus
Maxillary sinus
What are the main contents of the orbit?
Eyes Extrinsic ocular muscles Ligaments supporting the eye Optic nerve Branches of ophthalmic artery The lacrimal apparatus Adipose fat
What makes up the outer fibrous layer of the eye?
Cornea
Sclera
This is a complete layer
What makes up the middle vascular layer of the eye?
Iris
Ciliary body
Choroid
This is incomplete anteriorly. Anterior aperture (in iris) is called pupil
What makes up the inner sensory layer of the eye?
Retina
Is present posteriorly but anteriorly it stops short just in from of the equator of the eye.
What part of the eye produces (secretes) aqueous humour?
Ciliary body
Name the intrinsic muscle of the eye
Ciliaris
Constrictor pupillae
Dilatory pupillae
What is the location, action and innervation of the ciliaris muscle?
Location: Ciliary body
Action: Accommodation
Innervation: Parasympathetic via cranial nerve IIIn
What is the location action and innervation of the constrictor papillae?
Location: Pupillary border of iris
Action: constrictor
Innervation: Parasympathetic via cranial nerve IIIn
What is the location, action and innervation of the dilator papillae muscle?
Location: Radically running muscle in iris
Action: Dilator
Innervation: Sympathetic innervation
What produces the eye movements?
Extrinsic muscles of the eye
Describe intorsion and extorsion of the eye
These movements occur when the head is tilted.
In order to keep the eyeballs focussed on an object the eyes rotate in the opposite direction.
When the top of the eye rotated towards the nose it is called as intorsion, and when it rotates away from the nose it is extortion.
Describe the movements of the eye
Elevation: looking up
Depression: looking down
Abduction: looking laterally
Adduction: looking medially
Intortion: rotation of top of eye towards nose
Extortion: rotation of top of eye away from nose
How many extrinsic muscles of the eye are there?
There are 6 muscles which move the eye - four of these have a straight course (recti) and two are oblique.
In addition the elevator of the upper eyelid is also considered as an extrinsic eye muscle even though it has no action on the eyeball itself.
What is the action of the medial rectus?
Adduction
What is the action of the lateral rectus?
Abduction
What is the action of the superior rectus?
Elevation
Adduction
Intortion
RAD SIN
Rectus = adduction, Superior = intortion
What is the action of the inferior rectus?
Depression
Adduction
Extortion
What is the action of the superior oblique?
Depression
Adduction
Intorsion
Remember obliques attach to posterior of eye
What is the action of the inferior oblique?
Elevation
Abduction
Extorsion