76 Flashcards
orbit composed of
os lacrimale
maxilla
the 3 tunics of the eyeball
sorrund the gelatinous center
1 - t. externa: fibrous complete tunic
- sclera and cornea which meet at the limbus
2 - t. media: mainly blood vessels and smooth mm
- choroid, corpus ciliare and iris, all together the UVEA
3 - t. interna: mainly nervous tissue directly related to vision
- pars optica retinae
- pars ceca retinae
sclera of the t. externa/fibrosa
- elastic and collagenous fibers interconnect
- vorticose veins, small ciliary arteries and nerve fibers pierce the sclera at anulus sclearae
vagina bulbi membrane sep the sclera from the retrobulbar fat which provide the socket for the eyeball
meet the cornea at limbus
innervation: V1: n. nasociliaris(sensory), n. ciliaris longus
cornea of the t. fibrosa; layers
the substansia propria have several layers: 1 - conjunctiva 2. bowmans membrane 3. thick transparent fibrous layer 4 - descemets membrane 5 - endothelium(inner lining of cornea)
the transparency of cornea
level of hydration is highly important: it is avascular so it is dependant on aquous humor and air for nutrients and oxygen
aqous humour is prod by ciliary processes of the ciliary body: nutrients for lens and cornea
choroid of the t. media/vasculosa
- lines sclera from optic nerve to limbus
- blood vessels within pigmented CT, supplied by ciliary arteries and drained by vorticose veins
- tapetum lucidum akared eye, light reflecting area that help in night vision
corpus ciliare of the t. vasculosa
- thickening of limbus include the ciliary muscle,
- control shape of the lens
- ciliary epith: prod aqeous humour(pl. ciliare)
- proc. and m. ciliare(attach to margo cilearis on iris)
innervated by EW nucleus(PS); III n. oculomotorius for optical occomidation, plexus caroticus int(symp)
uvea
corpus ciliare, choroid and the iris
- tissue layer that deliver o2 and nutrients to eyeball = t. media, t. vasculosa
iris: function
thin circular structure
- control diameter of pupil –> how uch light reach the retina: m. dilator pupilae&m. spnincter pupillae
- determine the eye color
innervation: innervated by EW nucleus(PS); III n. oculomotorius
aqueous humour circulation
prod by plexus ciliaris -> anterior chamber->canal of schlemm aka scleral venous sinus in the angulus:
- in the angulus we find ligg. pectinati with spatium iridocornealis btw where the AqH pass through and into the blood
t. interna aka t. nervosaanterior
anterior pars ceca retinae and posterior pars optica retinae: has fovea: macula densa: 1:1 fiber: receptor, create sharp vision
at the point where the optic nerve enters the eyeball we have the discus opticus aka blind spot - area cribrosa: here enter n. opticus II, and a. centralis retinae
the muscles of the eye
go towards the fissura orbitalis, inserting on crista pterigoideus
straight muscles of the eye: action and innervation
III oculamotor nerve: - m. recti dors: elevate eyeball - m. recti ventr: depress eyeball - m. recti medialis: adduct eyeball VI abducens - m. recti lateralis: adduct eyeball
olique mm of the eye: action and innervation
o/i on eyeball
IV n. trochlearis
- dorsal oblique m: inward rotation of eyeball
- move oppositely bc around trochlea of orbit
III n. oculomotorii
- ventral oblique m.: outward rotation of eyeball
retractor and levator mm of eye: action and innervation
VI n. abducens
- m. retractor bulbi - retract eyeball
III n. oculomotorii
- m. levator palpebrae superioris - elevate upper eyelid
fat of periorbita
corpus adiposum orbitae
orbital fascia
periorbita: cone shaped fibrous membrane that enclose eyeball with nerves. vessels, muscles
septum orbitae: 2 semilunar fibrous membranes, margin of eyelids to the tarsi of eyelids
fasciae muscularis
superficial: loose and fatty, envelopes m. levator palpebrae superior and gl. lacrimalis
prof: fibrous: arise form eyelids to limbus, vagina bulbi; envelopes around eyeball and reflect around optic n. and bulbar m.
eyelids
superior et inferior
musculofibrous, free margin=commisura palpebrarum lat/med
lig palpebra lat/med: fibrous connection btw commissura and margin of eyelid
gl. lacrimalis
has duct system that convey lacrimal fluid after it has from ductus excretorii has washed over cornea into nasal cavity through ducta lacrimalia, into saccus lacrimalis into another duct for evaporation ( crosses limen nasi)
3rd eyelid
plica semilunaris conjunctiva with the membrana conjunctiva posterior to it connected to edge of cornea, reflect themselves to the anterior surface of the eye
nucleus bulbi - nucleus of the eye
behind the lens, we have the corpus vitreum with fovea lentis supporting the lens. a canalis hyaloidea is present for the a. hyaloidea(embyo)
posterior and anterior to the retina we have the camera bulbi p/a
blood supply of the eye - the supf system
1- conjunctivalis - episcleral-> supf (sclera)
- r. conjunctivalis
- r. episcleralis
both ex a. othalmica ext, ex a. max
blood supply of the eye - the middle system
ciliar system
a. ciliaris post/anterior
ex a. opthalmica ext, ex a. max
