contents of orbit Flashcards
vessels of orbit
ophthalmic artery, superior and inferior ophthalmic vein
orbital septim
on upper and lower margin orbital fascia sends of flap like continuations to the eyelids called orbital septum
suspensory ligament
tenons capsule lower part is thickened made from the union of margin of sheaths of inferior rectus and inferior oblique muscle
and lateral and medial check ligament
extraocular muscles: voluntary
1. four recti: superior rectus inferior rectus medial and lateral rectus 2.two oblique: superior and inferior oblique levator palpebral superioris elevates the upper eyelid
extraocular muscles: involuntary
superior tarsal deeper portion of levator palpebral superioris and inserted into upper margin of sup tarsus
elevates the eye
inferior tarsal extends from fascial fascia of inferior rectus and inferior oblique and inserted into inf tarsus
depresses the lower eyelid
orbitalis bridges inferior orbital fissure
four recti arises from and its location
they arise from tendinous ring of zinn and its in the middle and superior orbital fissure
lateral rectus additional head
tendisnous head with arsis from orbital surface of the greater wing of sphenoid
abducent nerve passes between the two heads
origin and superior obliqe
undersurface of the lesser wing of sphenoid superiormedial to optic canal
origin of inferior oblique
body of the maxilla lateral to lacrimal grove
origin and levator palberal superioris
orbital surface of the lesser wing of sphenoid anteriorsuperior to optic canal and to the origin of superior rectus
insetion of recti
posterior to limbus into the sclera
insertion of superior oblique
tendon of superior oblique passes through a fibrocartilaginous pulley and attches to the trochlear fossa of frontal bone
passes laterally downward and backward below the superior rectus attaches to sclera behind the equator of eye ball between the superior and lateral rectus.
inferior oblique insertion
passes laterally upwards and backwards below the inferior rectus deep to lateral rectus and near the superior oblique but below and posterior
levator labbi superioris insertion
tendon divides into 2 superior (voluntary)
inferior (involunatry)
superior attaches to anterior margin of sup tarsus
and inferior attaches to upper margin of sup tarsus
nerve supply of voluntary muscles
- superior oblique (IV) trochlear
- lateral rectus (VI) Abducent
and the rest of them which is medial inferior superior rectus and inferior oblique and a part of levator palpebral is supplied by oculomotor
elevation of eyeball
superior rectus
inferior oblique
depression of eyeball
inferior rectus
superior oblique
medial roation adduction
medial inferior and superior rectus
lateral rotation abduction
lateral rectus superior and inferior oblique
intorsion
superior rectus and oblique
extorsion
inferior rectus and inferior oblique
terminal branches of oculomotor artery
supratrochlear and dorsal nasal
branches of oculomotor artery
central artery of retina and after piercing dura matter it gives lacrimal artery
central retinal artery
first is below optic nerve then peirces the dura matter of the nerve and runs forward till it reaches optic disk
end artery
occlusion of this artery results in blindness
branches from lacrimal artery
- branches to lacrimal gland
- 2 zygomatic branches
- lateral palpebral to supply eyelids
- a recurrent meningeal artery which leaves the medial cranial fossa through superior orbital fissure
- branch to muscles of orbit
branches from main trunk of ophthalmic artery
- posterior cilliary ( long and short) supplied iris and choroid
anterior cilliary which given from the branches supplying the muscles - supratrochlear and supraorbital supllies the skin of forehead
3,. ant and post ethmoidal suplllies ethmoidal air sinuses and a branch of ant ethmoidal supplies a part of your nose - lateral palberal supplies eye lids
- dorsal nasal supplies upper part of your nose
opthalmic veins
sup ophthalmic: above ophthalmic nerve passes through superior orbital fissure and drains into cavernous sinus
communicates anteriorly with supraorbital and angular vein
in ophthalmic: below ophthalmic nerve branches off from lacrimal sac, eyelids, orbital muscles either joins with superior ophthalmic or drains into cavernous sinus
communicates with pterygoid plexus of vein’s by passing through inferior orbital fissure
lymphatics of orbit
preauricular lymph nodes
nerves of the orbit
- optic (II)
- ciliary ganglion
- oculomotor and trochlear (III AND IV)
- branches of ophthalmic (V1) and maxillary divisions of trigeminal (V2)
- abducent (VI)
- sympathetic nerves
optic nerve relations to orbit
- apex of eyeball the nerve is surrounded by recti muscles ciliary gnaglio is present between lateral rectus and optic nerve
- central artery and vein of retina pierces the nerve
- superiorly crossed by ophthalmic artery nasocilliary nerve and superior ophthalmic vein
- inferiorly crossed by nerve to medial rectus
- near eyeball nerve is surrounded by fat which has cilliary nerve and vessels
spread of infection to cavernous sinus
due to anastomose of facial veins fand ophtlamic veins from the orbital and nasal regions
optic neuritis
pain in or behind the eye on ocular movements
papilleoedema is less but loss of vision is more
papilloedema
when optic disc is swelled up
retrobulbar neuritis
when there is no papilloedema only loss of vision then it retrobulbar neuritis
ciliary ganglion roots
parasympathetic, sensory and sympathetic
parasympathetic ciliary ganglion roots
arsises from the nerve to inferior oblique
preganglionic fibers that begin in ediger westphal nuscleus relay in the ganglion
post ganglionic passthrough short cilliary nerves and supply the sphincter pupillae and ciliaris
sensory root of ciliary ganglion
arises from nasocilliary nerve and does not relay
sympathetic root of ciliary ganglion
arsis from internal carotid sheath
postganglionic arsis from the superior cervical ganglion
they leave from short ciliary nerves and supply the blood vessels of eyeball and dilator papillae
ophthalmic divisions of trigeminal nerve
- frontal - supra orbital and supra trochlear
- nasociliiary- branches to nasociliary ganglion
2-3 long cilliary nerves
ant and post ethmoidal
infratrochlear - lacrimal - branch to upper eyelid and secretomotor to the lacrimal gland
lacrimal nerve
enters the orbit through lateral part of superior orbital fissure
anteriorly has communication with zygomaticotempora ( recieves its secretomotor fibers to gland though greater petrosal through communication with zygomaticotemporal)
supplies upper eyelid, conjunctiva and the gland
to the gland it has sensory fibers
frontal nerve
largest division of trigeminal
enters the orbit through the lateral part of superior orbital fissure
divides into supratrochlear and supra orbital
supratrochlear
leave the orbit above the trochlea
supplies the upper eyelids, conjunctiva and the skin on the forehead above the root of the nose
supraorbital
emerges from the orbit through supraorbital foramen divides into medial and lateral branches
supplies the conjunctiva, central part of upper eyelid, skin over the forehead upto the vertex or lambdoid suture and frontal air sinuses
nasociliary nerve enters orbit thorugh and terminal branches are
medial part of superior orbital fissure and terminal branches are infra trochlear and anterior ethmoidal
communicating branch to nasocilliary ganglion
makes the sensory root often mixed with sympathetic root
long cilliary fibers
supply sensory fibers to cornea, iris ciliary body and also trasmit some sympathetic fibers to dilator pupillae
posterior ethmoidal
leave through posterior ethmoidal foramena nd supply the ethmoidal and sphenoidal sinuses
infratrochlear
emerges though the anterior ethmoidal foramen and supplies the conjunctiva, lacrimal sac, caruncle, medial ends of eye lids and upper part of the external nose
anterior ethmoidal
emerges from anterior ethmoidal foramen goes into the nose through a slit in the side of crista gali gives off two internal nasal branches medial and lateral to mucosae of the nose
and comes off from the lower part of the nose as external nasal and supplies the lower half of the nose
infraorbital nerve
branch of maxillary nerve
enters the orbit through inferior orbital fissure runs on the roof of maxillary sinus then to infraorbiral groove, canal and then entrs the face through infraorbital formaen and gives off palpebral nasal and labial branches
branches of IO nerve
middle superior alveolar nerve
anterior superior alveolar nerve
terminal branches: labial nasal and palpebral
middle superioe alveolar nerve
arises from infraorbital grove and supplies the upper premolar teeth
anterior superior alveolar nerve
arises from infraorbital canal and supplies the upper incisors and canines, maxillary sinus and anteroinferior part of nose where it communicates with the anter ethmoidal and anterior palatine nerves
terminal branches of IO
supplies a great part of face and the mucosa’s membrane of upper lip and cheek
zygomatic nerve
branch of maxillary nerve given off the pterygopalatine fossa
gives off 2 branches zygomaticotemporal and zygomaticofacial
and the communicating branch to lacrimal gland which has secretomotor fibers are given off from the zygomaticotemporal branch
dialator puppilae of iris is supplied by
ophthalmic nerve, nasocilliary and long cialiary nerve
other sympathetic nerves enter the orbit
plexus around opthalmic artery
directly thoigh internal carotid sheath enters through superior orbital fissure and goes to the ciliary ganglion
filaments through oculomotor, abducent, opthalmic and trochlear
