Green 2 Flashcards
How many msucle fibres to neurone in EOM motor unit
1:2 to 1:7
Where are accessory lacrimal glands of Krause and Wolfirng located?
Krause - around the conjunctival fornix
Wolfring - at border of tarsal plate
What does the CRAO supply? Choroidal cirulation?
CRAO branches supply inner 2/3 retina
Outer third is choroidal circulation
What does Wieger’s ligament connect
Anterior hyaloid face to posteiror lens capsule
Adherence becomes weaker with age
What is the length of lacrimal canaliculi
2mm vertical segment, 8mm horizontal segment
Where doe pterygopalatin fossa lie? What are boundaries?
Posterior and inferior to orbit
MAxilla nateirorly
Sphenoid poseetiorly
Sphenoid superiorly
Palatine bone inferiorly and medially
Open to infratemporal fossa via pterygomaxillary fissure laterally
Most likely place for globe rupture?
Posterior to insertion of rectus musles
Corneoscleral junction
Site of previous surgical incisions
What layer of choroid are permeatble to fluorescin?
Diffuse leakage of fluorescein dye seen on angiography occurs from the choriocapillaris due to fenestrated epithelium
What does ELISA use to label?
Antibodies or antigens are lablled with an enzyme that induces a colour change in sa substrate when present
describe phototransduction
- 11-cis retinal (chromophorefrom vitamin A) bound to opsins via lysine residue
- Photo absorption convers it to all-trans retinal (photoisomerisation)
- All trans retinal coverted to all-trans retinol in photoreceptor outer segment
4, Transported to RPE cells where it is reconstituted to 11-cis retinal isoform (vit A)
What NT between photoreceptor and bipolar cells
Glutamate
What is a property of actin
Microfilament that is flexible
What is the order of gamete fusion development
Zygote - union of gametes
Morula - mass of cells
Blastocyst - sphere of cells
What sinuses are present at birth?
Ethmoid and maxillary
when does the sphenoid sinus develop?
2-3 years after birth
Adult size at age 14
When does the hyaloid artery disappear?
34 weeks
What does von hippel lindau syndrome lead to?
AD chromosome 3
Retinal angiomata - capillary haemangioma
Renal cell cancer
Phaeochromocytoma
What are regularoty mechanisms of the complement system
Factor H
Factor I
C1 inhibitor
Sialic acid
What enzyme enables bacteria to resist phagocytosis?
Coagulase
Converts fibrinogen to fibrin which coats bacterium to isolate from immune defeces
What are endotoxins
Derived from cell wall of gram negative bacteria
Lipopolysaccharieds
Activate alternative complement pathway
HEat stable
What immune reaction does toxocara cause
IgE mediated immune response
OCa transferred in feline faeces
What is visual angle subtended by letter on snellen chart
5 minutes of arc
To recognise letter eye must have resolution of 1 minute of arc
second vs minute vs degree
60 seconds of arc in a minute
60 minutes of arc in a degree
Worse prognosis cell type for choroidal melanoma
Epithelioid cell
Monosomy 3
Duplication 8q
Older age
Larger tumour
Extrascleral extension
Spindle cell has better prognosis
