Orbital muscles ,fascia and lacrimal apparatus Flashcards
(28 cards)
بسم الله الرحمن الرحيم وبه نستعين
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CNS clincal rev: Dopamine Hypothesis of schizophrenia explain
It appears to be partly related to ↑ dopamine activity in certain neuronal tracts.
(Too much release of dopamine, too many dopamine receptors, or hypersensitivity
of dopamine receptors to dopamine or combination of all mechanisms)
Evidences for dopamine hypothesis of schizophrenia ?
CNS CLINCAL REVISION
Evidences:
-Most antipsychotics successful in treating schizophrenia are dopamine receptor
antagonists = Their ability to act as antagonists of Dopamine type 2 receptors.
- Cocaine and amphetamines ↑ dopamine activity and can → schizophrenic-like
symptoms
Mention layers of Eye ball
3 layers :
Fibrous :- Cornea and sclera and conroscleral junction in between
Vascular : Choroid + Ciliary body + Iris
Nervous : Retina
Mention fascia of orbit
Periorbiral fascia = periosteum
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Bulbar fascia starting from the corneoscleral junction and
surrounds the optic nerve and
leaves an episcleral space for free movement of eye ball and
pierced by extraocular muscles and
Forming Medial and lateral check ligaments and suspensory ligament for eye ball
mention structures of eyelid
Skin
superficial fascia containing the palpebral orbicularis oculi
Palpebral fascia = tarasal palates + ligaments
Conjunctiva lining the eye lid reflected to line the sclera till conreoscleral junction froming the superior conjuntival fornix and inferior conjictival fornix
palpebral part of orbicularis oculi found in which layer ?
Superficial layer of eye lid
Clinical revesion : Hypofunction of this pathway responsible for negative symptoms and cognitive dyfunctions of
schizophrenia.
The 5 A’s of schizophrenia (negative symptoms):
1. Anhedonia
2. Affect (flat)
3. Alogia (poverty of speech)
4. Avolition (apathy)
5. Attention (poor
Mesocortical pathway (VTA to Prefrontal cortex): Inadequate dopaminergic activity.
Responsible for cognitive, executive functions, affect ,and emotions.
Mention intrisnic muscles of eye ball
-Ciliary
-Constrictor pupillae
-Dilator pupillae
Ciruclar constricror pupillae casue ,,,while radial dilator pupullae casue ….?
Miosis
Mydriassis
Extirnsic muscle of eye ball mention
Levator palpebrae supeiroris
4recti
2oblique
Mention layers of levator papebrae superiors
superficial lamella
Muller invoulntary
Mention layers of levator papebrae superiors
superficial lamella
Muller invoulntary
arises just anterior to optic canal to be inserted in 3 areas:
skin upper eyelid - tarasal plate - superior conjinctival fornix
Mention nerve supply of levator palpebrae superioes
Occulumotr CN3 + Sympathatic for Mullers muscles
4 recti enter orbit through ?
Annulus of zinn
Common Tendinuous Ring !
to be inserted in corneoscleral junction ( sclera infront of equator plane of eye ball )
Nerve supply of Extraocular muscles
SO4 LR6 otherwise 3
Superior oblique By Trochlear nerve
Lateral rectus by abucent
other wise by occlumotor !
Superior oblique aresie from ……… of orbit just ,,,,,,,, to optic canal
Roof of orbit just superomedially to optic canal
Inferior oblique arese from the ,,, of orbit just,,,, to lacrimal groove
note that lacrimal goove is in medial orbit !
Floor lateral to lacrimal groove
Both of oblique muscles are inserted in ?
Sclera behind the euqator plane of eye ball
Compare between Superior recuts and superior oblique action
Superior rectus Elevation , adduction and introsion
Superior oblique depression abduction … intorsion
Compare between Inferior Rectus and Inferior Oblique action
Inferior rectus : depression abduction and extorsion
Inferior oblique :
Compare between Inferior Rectus and Inferior Oblique action
Inferior rectus : depression abduction and extorsion
Inferior oblique :elevation adduction and extorsion
Lacrimal apparratus show
Structures concenerd in Sceretion and Draining of Tears :-
Lacrimal gland
lacrimal canaliculi
lacrimal duct
nasolacrimal duct
Show path ot tears from my eye tears of my fears !
From lacrimal gland , the tears secreted then pass medially to Lacrimal punctum to The lacrimal caliculi then to the lacrimal duct to nasolacrimal duct to infreiro meatrus in the lateral wall of nose
mention nerve supply of the Lacrimal gland
Lacrimal of opthalmic of trigeminal nerve
Sensory and secretomotor fibers from Special lacrimatory nucleus