130: eye physiology, pathology, histology Flashcards
what is glaucoma?
Rasied intraoccular pressure from blocked canal of schlemm.
which cranial nerve innervates the ciliary body?
nasociliary nerve which is a branch of V1 (opthalmic branch of trigeminal)
sarcoma is what type of cancer?
connective tissue
carcinoma is what type of cancer?
epithelial tissue
squamous cells are found where in the eye ?
conjunctiva (flattened)
cuboidal epithelium is found where?
cornea endothelium ( square not flat)
what cells are the anterior corneal epithelium?
stratified non-keratinised squamous
which three structures make the uveal tract?
choroid, colliery body and iris
job of the choroid
blood supply to the eye
what are stroma?
fibrus tissue of the iris containing pigmentation
which nerve innervates the lacrimal gland?
lacrimal nerve ( branch of V1)
where do you find goblet cells?
in the squamous epithelium of the conjunctiva.
closed angle glaucoma is what?
the angle of the trabecular leading to the canal of schlemm is narrowed - build up of pressure in posterior chamber.
what is herpes simplex keratitis?
corneal ulceration due to HSV (keratitis means inflammation of the cornea)
who is high risk for acanthamoeba infection
contact lense wearer
autosomal dominant disease affecting the cornea. slowly progressing glare and blurring, corneal odema, vision loss, loss of endothelial cells
Fuch’s Dystrophy
what do melanocytes do?
colour the retina
glass eye and enlarged liver….
metastatic melanoma
intraoccular tumor in children
retinoblastoma
flexner-wintersteiner rosettes are a sign of?
retinoblastoma - spoke and wheel cell formation in retina.
the retinal artery is a branch of…
the opthalmic artery
the temporal artery is a branch of…
the external carotid
giant cell arteritis is…
inflammation of the temporal arteries
giant cell arteritis presents as…
blurred vision/ sudden blindness, headaches and tender temporal artery
pathophysiology of cataracts…
lens protein degeneration over time
where is the anterior chamber?
in front of lens, behind the cornea
two types of age related macular degeneration
wet - neovascular…new vessel growth in the choroidal area
dry - non-neovascular can see drusen ( yellow deposits under retina
anti vegf is used to treat wet AMD..how does it work?
blocks vascular endothelial growth factor to reverse new vessel formation
5 Steps of Phototransduction:
- light photon induces change of 11-cis retinal to trans-retianl which disassociated from opsin
- opsin activates transducer
- transducer activates phosphodiesterase
- cGMP becomes 5 GMP
- Na channels close - hyperpolarisation
which cells regulates the ganglion cell?
bipolar
which cells are interneurones of the retina
amacrine cells ( modulate whats received mostly using GABA and glycine)
what is protanopia?
red colour blindness ( x linked)
what is deuteranopia?
green colour blindness
what is tritanopia?
blue colour blindness (autosomal dominant chromosome 7)
which hormone makes you sleep when its dark?
melatonin
which structures make melatonin?
pineal gland, skin, retina, GI tract.
what is N-acetyl-5-methoxytryptamine?
melatonin.
