Qbank must know 2 Flashcards
Indocyanine green (ICG) wavelength
ICG dye absorbs light of wavelength 805nm and reflects light of wavelength 835nm
botulinum toxin (mechanism)
Botulinum toxin inhibits the release of ACh from PREsynaptic nerve terminals
largest cranial nerve is:
the trigeminal
sympathetic trunk extends
extends from the base of the skull to the coccyx
sympathetic trunk enters the thorax
It enters the thorax through the neck of the first rib
CMO cystoid macular oedema. Which retinal layer accounts for the petalloid appearance in fluorescein angiography?
Outer plexiform layer
The radiating fibres of Henle in the outer plexiform layer lead to the cystic spaces in CMO.
Jaw opening muscles
lateral pterygoid and mylohyoid.
Short posterior ciliary artery supply
choroid and and outer4 layers of retina
Argyll Robertson pupil
light near dissociation
light absent
near present
defect afferant pathway
Adie’s tonic pupil
mid dilated
lesion in ciliary ganglion
sluggish everyway
corneal clarify factors
regular arrangement of epithelium
regular arrangement of lamellar laminin (GAG keratan sulphate)
Endothelial pump Action
avascular
diameter of the adult cornea
11.7 mm horizontally and 10.6 mm vertically.
Diploë
is the name of the spongy bone that separates tables of compact bone
Sutures
immobile, rigid articulations
Site of opening into nose: Middle meatus
? sinus
Frontal
Maxillary
Ethmoidal (anterior and middle groups)
Site of opening into nose: Superior meatus ? sinus
Ethmoidal (posterior group)
Site of opening into nose: recess or superior meatus ? sinus
Sphenoidal
posterior blepharitis
Meibomian gland dysfunction
Meibomian glands
are modified sebaceous glands which produce an oily substance that forms part of the precorneal tear film
chalazion
A chalazion is a lipogranulomatous inflammatory cyst resulting from a blocked
Meibomian gland.
important differences between extraocular muscles and normal skeletal
muscle
1.The connective tissue of the extraocular muscles,
including the epimysium (a sheath surrounding the whole muscle) is generally thin
and delicate by comparison
2.The muscle fbres are more loosely packed, with the
larger diameter (10–40 μm) fbres occupying the centre and the smaller fbres (5–15
μm) placed peripherally in the muscle.
3.Extraocular muscle also has many specialised
sensory and proprioceptive endings, including long muscle spindles almost 1 mm in
length, which provide feedback about muscle activity to the central nervous system
Lastly, extraocular muscle is more vascular than normal skeletal muscle.
Schwalbe’s line marks the termination of
Descemet’s membrane
lens capsule is thinnest at
Posterior pole
posterior pole 2–3 µm
The anterior pole is 9–14 µm
peri-zonular region the capsule is 17–28 µm thick
vitreous base attaches
peripheral retina and pars plana
vitreous base is a three-dimensional band that extends approximately 2 mm
either side of the ora serrata and is usually attached to the peripheral retina and pars plana
Bruch’s membrane is composed of 5 layers (basement)
the basement membrane of the choriocapillaris, an outer collagenous layer, an elastin layer, an inner collagenous layer and the basement membrane of the RPE.
lateral canthal tendon inserts into
Whitnall’s tubercle
Whitnall’s tubercle
is a small prominence of bone lying just inside the lateral orbital rim. Eisler’s fat pad lies immediately anterior to the lateral canthal tendon, deep to the orbital septum
Nerve innervation of iris (parasympathetic, sympathetic, and sensory)
The parasympathetic nerves supplying the iris originate in the Edinger–Westphal nucleus and synapse in the ciliary ganglion. Their postganglionic fibres travel via the
short ciliary nerves and supply the sphincter pupillae muscle
The dilator pupillae is predominantly innervated by unmyelinated sympathetic fibres originating in the superior cervical sympathetic ganglion
The sensory innervation of the iris is via both the long and short ciliary nerves, which derive from the nasociliary nerve (and ultimately V1)
optic canal connects
middle cranial fossa and the orbital apex
posterior to anterior orientation of the optic canal
Inferolateral
posterior to anterior the optic canal runs slightly inferiorly and around 36o
laterally through the sphenoid
optic canal narrowest part
orbital opening and widens posteriorly
ciliary body
ciliary body has a greater anteroposterior length temporally than nasally, and is generally at its longest inferotemporally. It varies with the size of the globe, measuring 5.6–6.3 mm temporally and 4.6–5.2 mm nasally
A The blood supply to the ciliary body
via the anterior ciliary arteries and the long posterior ciliary arteries
middle radial layer of the ciliary muscle is continuous with
corneoscleral meshwork
outer longitudinal layer of the ciliary muscle attaches
scleral spur