The orbit
Anatomy : it`s pyramidal in shape , cavity having roof ,floor, medial ,
lateral wall .
- Apex posterior . base anterior.
- Orbital volume 30 ml.
- Globe volume 6-7ml .
Orbital fissure and foramina :
1- optic foramen (canal ) connection the orbit with middle cranial fossa .
It`s transmits: MCQ
Optic nerve .
ophthalmic artery .
sympathetic twigs around the artery .
2- superior orbital fissure MCQ:
Live = lacrimal n
Free = frontal n Superior ophthalmic vien outside the ring
To = trochlear n
See= superior division
No = nasociliary n
Inferior ophthalmic vien inside the ring
Insult = intrerior division 3rd n .
AT ALL = abducent .
N.B no lymphatic’s inside the orbit .
- NB: there is relation between the orbit & the brain :
1- optic foramen .
2-Orbital roof separates the orbit from ant cranial fossa .
3- inferior orbital fissure : MCQ& SLID
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,D.Hanan Darif 2016
1- maxillary division of trigeminal n ( zgyomaticn )
2- Infra orbital artery & n .
4- inferior orbital canal :MCQ?& SLID
Infra orbital vassals .
Infra orbital nerve .
Anatomy of the cavernous sinus :
Relation :
medially : sella tursica ( pit .gland ) & sphenoid sinus.
Laterally : temporal lobe .
Contents :
1. The cavity contains .
Internal carotid artery ( surrounded by sympathetic plexus ) .
Abducent n.
2. The lateral wall contains ( from above down wards )
3rd n .
4th n .
Ophthalmic . n .
Maxillary . n .
- So the infection come to cavernous sinus from :
- 1-face and orbit ( dangerous area ) via ophthalmic vein .
- 2- middle ear ( inf .petrosal sinus ) 3- mastoiditis
- 4- mouth and pharynx . 5- blood borne (metastatic).
- Organism : common staph & strepto .
Proptosis
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Def : It`s protrusion of the eye ball outside the orbital rim .
Couses :
I) – congenital : e.g :
Dermoid cyst painless , slowly growing .
Meningo – encephalocele : herniation of apart of meninges & brain
through a defect in the orbital roof - proptosis .
. - pulsating .
- on crying .
II)- Acquired :
1- traumtic e.g
a) retro bulbar hematoma .
b) surgical emphysema .
c) carotid - Cavernous fistula (A- V shunt ) :
Pulsatile protosis .
Disappear on pressure on the carotid .
2- inflammatory :
Acute :
a) Orbital cellulites .
b) Cavernous sinus thrombosis = varices .
c) Panophthalmitis .
d) Sinusitis .
Chronic :
a)Specific : T.B, syphilis .
b)Non- Specific: orbital- pseudo tumor .
Orbital pseudotumor :
Def : - It`s uncommon (rare).
-non – neoplastic .
-non – infection .
-involved any soft tissue .
Cause : un known
presentation :
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