Anatomy Flashcards
What bones make up the orbit?
zygoamtic spehoid ethmoid frontal maxillary lacrimal nasal
What passes through the superior orbital fissure?
opthalmic veins
What passes through the supraorbital notch/foramen?
nerves to go to the skin on the forehead
What walls does an orbital blowout fracture usually affect?
medial wall and orbital floor
What is the CT sign of an orbital blow out?
teardrop sign
What do the eyelids contain?
tarsal plates - maintain shape and secrete oil
tarsal glands - secrete lipids
orbital septium - sheet of fasica that stops spread of things to brain
orbicularis oculi - closes the eye (CN VII)
What are the two parts of the orbicularis oculi?
palpebral - inner
orbital - outer
What is the role of the lacrimal apparatus?
produces tears
What is the nerve supply to the lacrimal gland?
parasympathetic CN VII (facial nerve)
What is the pathway of tears?
Produced by the lacrimal glands, pushed to the medial angle, drains to the lacrimal puncta, reaches the inferior meatus of nasal cavity (hole)
What are the 3 layers of the eye?
outer fibrous layer
vascular layer
photosensitive layer
What is included in the outer fibrous layer?
sclera
cornea
What is included in the vascular layer?
ciliary body
iris
choroid
What is the anterior segment of the eye?
part infront of the lens
What is the posterior segment of the eye?
part behind the lens
What makes up the anterior segment of the eye?
anterior chamber - between cornea and sclera
posterior chamber - between iris and suspensory ligaments
What does the anterior segment of the eye contain?
aqueous humour
What secretes aqueous humour?
ciliary bodies
What does the posterior segment contain?
vitreous humour (contained in the vitreous body) cioquets canal
What connects the cornea and the sclera?
limbus
How is aqueous humour circulated?
produced by ciliary body
circulated within the posterior chamber and nourishes the lens
passes through the pupil into the anterior chamber and nourishes the cornea
reabsorbed into the scleral venous sinus at the intercorneal angle
Where does the opthalmic artery come off, what does it give off?
internal carotid artery
gives off ciliary arteries, nasal cavity branches and central artery of the retina
What is the venous drainage of the eye?
superior and inferior opthalmic vein
What 3 structures are found in the fundus of the retina?
macula
optic disc
fovea
What is the optic disc?
exit/entry point for all blood vessels and axons of CNII
devoid of all photoreceptors
What is the macula?
greatest density of cones meaning it has the highest visual acuity
What is the fovea?
center of the macula
From anterior -> posterior, describe the layers of the retina?
arteries and veins
axons of ganglion cells
ganglion cells
photoreceptor cells
What would obstruction of the retinal branch artery/vein result in?
loss of the corresponding visual field
What would interruption of flow to the central retinal artery result in?
loss of mononuclear vision
What are the characteristics of rods?
sensitive to low levels of light - good for night and peripheral vision
What are the characteristics of cones?
detailed vision and coulour vision
What are the muscles of the eye?
medial, lateral, inferior and superior rectus
superior and inferior oblique
levator palpebrae superiors
Where do the rectus muscles originate from?
common tendinous ring
Where do all of the rectus muscles insert?
sclera
What is the innervation of the lateral rectus?
Abducent nerve - CN VI
What is the innervation to the superior oblique?
trochlear nerve CN IV
What innervates all other muscles?
oculomotor nerve CN III
What muscles and nerve opens the eye?
levator with mullers muscle
CN III
What is the role of the lateral rectus?
abduct the eye
What is the role of the medial rectus?
adduct the eye
What is the role of the inferior rectus?
down and in
What is the role of the superior rectus?
up and in
What is the role of the superior oblique?
down and out
What is the role of the inferior oblique?
up and out
