Qbank must know Flashcards
Synaptic terminals of the cones
Pedicles
Synaptic terminals of the rods
spherules
How many ganglion cells, cones and rods are there in humans:
There are 1 million ganglion cells, 6 million cones and 120 million rods in the human retina.
How does The ophthalmic artery enters the orbit?
Infero-lateral
The ophthalmic artery enters the orbit infero-lateral to the optic nerve
Lamina vitrea
Bruch’s membrane
Lamina fusca
Sclera proper and then episcleral tissue.
Lamina cribrosa
Transmits the optic nerve
Lamina densa
Basement membrane of the corneal epithelium.
Ciliary body width, pars plicata, pars plana
5-6 mm wide
pars plicata. It is 2mm wide
pars plana. It is approximately 4mm wide
Pars plicata how many ciliary processes
70 ciliary processes
Eccrine glands
i.e., sweat glands
Apocrine glands
associated with hair follicles, i.e. Moll’s glands
Holocrine glands
meibomian glands, sebaceous glands, and glands of Zeis
Zonulae adherens
belt desmosomes
they are specialized adherens junctions between cells. Their main role is in mechanical adhesion.
Zonulae occludens
Tight junctions
They form a special junction between cells such that the passage of molecules and ions through the space between plasma membranes of adjacent cells is blocked, so materials must actually enter the cell
Desmosomes
link two cells together
Hemidesmosomes
attach one cell to the extracellular matrix.
Goldmann applanation tonometry diameter of flattening
diameter of flattening is 3.06mm
which is based on counterbalancing the corneal resistance and the capillary attraction of tears for the tonometer head.
suspensory ligament of Lockwood
Mnemonic: chess
double check double inferior
The suspensory ligament of Lockwood forms a hammock-like support for the globe. It is composed of:
-the sheath of inferior rectus
-the medial check ligament
-the lateral check ligament
-sheath of inferior oblique
Strong convex lens (distortion)
pin-cushion effect
strong concave lens (distortion)
barrel effect
inferior oblique inserts on which quadrant of the globe:
Posterolateral quadrant
The inferior oblique inserts on the posterolateral quadrant, mostly below the horizontal.
Adrenergic agonists cause:
Adrenergic agonists cause:
-mydriasis
-ciliary muscle relaxation
-increased aqueous formation (though selective alpha-2 stimulation will reduce formation)
-increased aqueous outflow
-constriction of conjunctival and episcleral vessels
-contraction of Muller’s muscle
Neurofibromatosis Type 1 is associated with
meningioma, glioma and phaeochromocytoma
Neurofibromatosis Type 2 is associated with
bilateral acoustic neuroma
corneal stroma: collagen
Type I collagen
lateral geniculate nucleus consists of how many laminae or cell layers:
6
The LGN consists of six laminae or cell layers.
Corneal crystalline deposits are a side-effect of which topical medication?
Ciprofloxacin-induced corneal crystalline precipitates
Prolonged use of ciprofloxacin may cause corneal crystalline deposits. These are probably due to precipitation of drug, which requires low pH for solubility.
Schlemm’s canal is lined by
Schlemm’s canal is lined by a single layer of non-fenestrated endothelium joined by tight junctions
Drainage canal of Schlemm is facilitated by micropinocytic vescicles which coalesce to form giant vacuoles within the endothelial cells.
Ultrasound A-scan have in a phakic eye? peak (5)
There are five A-scan peaks in a phakic eye:
1.corneal surface
2.lens anterior surface
3.lens posterior surface
4.ILM of the retina
5.sclera
cerebrospinal fluid vs blood
higher conc of Chloride and H+
Almost all constituents of CSF are found in lower concentration than that of blood with the exception of Chloride and H+, which are higher. Thus, the pH and the PO2 of the CSF are lower than that of the arterial blood. Protein is lower in the CSF (in fact it is almost absent in the normal CSF). The glucose in CSF is 2/3 that of the blood.
Sclera collagen
Type 1
The sclera is composed mainly of Type 1 collagen.
CT imaging in thyroid eye disease?
Fusiform muscle enlargement with sparing of tendons
Aqueous humour vs plasma
More acidic, more ascorbate, less protein
Compared with plasma, aqueous is slightly hypertonic and acidic. Aqueous has a marked excess of ascorbate (15 times greater than that of arterial plasma) and a marked deficit of protein (0.2% in aqueous as compared to 7% in plasma
Caruncle is supplied by
innervated by the infratrochlear nerve
superior medial palpebral arteries
Facial nerve mnemonic
Two zebras bite my cake
To Zanzibar by my car
Temporal, Zygomatic, Buccal, Marginal mandibular and Cervical branches.
Southern Blotting:
Southern blotting is a technique for analyzing DNA.
The steps are as follows:
1.restriction endonucleases cut human DNA into fragments
2.fragments are separated by gel electrophoresis
3.the fragments are denatured to single strands and blotted on nitrocellulose
4.specific radio-isotope labeled DNA probes are used to bind complementary strands on the blotted fragments
abducens nerve arterial relation
The sixth cranial nerve is pinned down near to its exit from the pons by the anterior inferior cerebellar artery.
goblet cells on the tarsal conjunctiva are called
Henle’s crypts
goblet cells on the bulbar conjunctiva nasal to the limbus are called
Manz’s glands
common cause of corneal verticallata (vortex keratopathy)
amiodarone
inferior oblique muscle originates
Just lateral to the nasolacrimal canal
The inferior oblique muscle has its origin on the maxillary bone just posterior to the inferior medial orbital rim and lateral to the nasolacrimal canal.
posterior pigmented iris epithelium is a continuation
non-pigmented epithelium of the ciliary body
anterior iris epithelial layer is a continuation of
anterior iris epithelial layer is a continuation of the pigmented epithelium of the ciliary body
Amiodarone is commonly associated with which ocular side-effect:
Amiodarone can commonly cause corneal opacification known as vortex keratopathy
hamartoma
A hamartoma is comprised of tissue elements normally found at that site
choristoma
A choristoma is comprised of normal tissue in an abnormal location (e.g. a dermoid).
What is the scleral spur?
This is an anterior protrusion of the sclera which marks the attachment of the ciliary body’s longitudinal fibres.
What are the 3 fundamental properties of lasers?
Monochromaticity
coherency
Collimation
How does sodium fluorescence dye work?
It absorbs blue light and emits yellow green light which is detected by a fundus camera with cobalt blue excitation and yellow green barrier filters
mutton fat KPs
are formed by macrophage
There are five hormones which counteract the hypoglycemic effect of insulin:
glucagon
cortisol
growth hormone
adrenaline
noradrenaline
Which is the only extraocular muscle not to originate at the orbital apex:
the inferior oblique
The inferior oblique is the only extrocular muscle to originate outside the orbital apex. It originates behind the orbital margin lateral to the nasolacrimal duct and passes beneath the inferior rectus to insert on the sclera between the inferior rectus and the lateral rectus; with the posterior margin of the insertion corresponding to a point 2mm below and 2mm lateral to the macula.
mechanism Cyclosporin and tacrolimus
decrease levels of IL-2.
insert into the lateral tubercle of Whitnall (3)
suspensory ligament of eyeball
lateral canthal tendon
check ligament of eyeball
Ironically DOES NOT INSERT AT WHITNALLS TUBERCLE Whitnall’s ligament inserts 10 mm above the tubercle of Whitnall.
Whitnall’s ligament inserts how many cm, where?
10 mm above the tubercle of Whitnall.
signal modulation retina cells
Amacrine cells, horizontal cells
Bipolar cells function
Bipolar cells serve as a connector or intermediary between the photoreceptor and the ganglion cells
Muller cells are glial cells function
Muller cells are glial cells and perform a supportive role both structurally and nutritionally.
Muller cells are glial cells function
Muller cells are glial cells and perform a supportive role both structurally and nutritionally.