Paper 2 Flashcards
(142 cards)
1
Q
Which nerve supplies the maxillary sinus
A
Infraorbital nerve- branch of maxillary division of trigeminal nerve
2
Q
Which nerve involvement can result in cheek numbness after orbital blowout fracture
A
Infraorbital nerve- branch of maxillary division of trigeminal nerve
3
Q
Where does the inferior orbital fissure lie
A
lies in the lateral orbit floor between greater wing of sphenoid and maxilla
4
Q
What is the inferior orbital fissure an opening from
A
from infratemporal and pterygopalatine fossae
5
Q
Structures passing through inferior orbital fissure
A
Inferior ophthalmic vein which passes out of the orbit and drains into the pterygoid venous plexus
The infraorbital artery and vein
Two branches of V2 (Maxillary nerve which becomes infraorbital nerve, Zygomatic nerve)
Branches of the pterygopalatine ganglion
6
Q
What is the action of the corrugator supercilli
A
Draws the eyebrows medially toward the nose- innervated by CNVII
7
Q
How many eyelashes are found in the upper lid
A
150
8
Q
How many eyelashes are found in the lower lid
A
75
9
Q
Where does the inferior oblique muscle originate from
A
Only muscle not arising from the orbital apex. Arises from the orbital plate of the maxilla on the medial side of the orbital floor posterior to the orbital margin
10
Q
What is the height of the tarsal plate in the upper and lower lids
A
Upper: 10mm
Lower 5mm
11
Q
Which bone does the superior oblique originate from
A
Sphenoid
12
Q
What is the ratio of EOM to skeletal muscles
A
1:2 to 1:7
13
Q
Where is the lesion caused by a superior bitemporal hemianopia
A
Inferior to chiasm: Pituitary adenoma
14
Q
Where is the lesion caused by an inferior bitemporal hemianopia
A
Superior to chiasm: Craniopharyngoma; suprasellar or olfactory groove meningioma
15
Q
Where is the lesion caused by a junctional scotoma
A
Anterior to chiasm at junction of optic nerve: sphenoid meningioma
16
Q
Where is the lesion caused by a binasal field defect
A
Lateral to chiasm: Dilation of 3rd ventricle in hydrocephalus
17
Q
Where are the accessory glands of Krause located
A
Conjunctival fornix
18
Q
Where are the accessory glands of Wolfring (Ciaccio glands) located
A
Border of tarsal plate
19
Q
Branches of the External Carotid Artery
A
Some Anatomists Like Freaking Out Poor Medical Students:
S – superior thyroid artery
A – ascending pharyngeal artery
L – lingual artery
F – facial artery
O – occipital artery
P – posterior auricular artery
M – maxillary artery
S – superficial temporal artery
20
Q
What are the terminal branches of the ECA
A
M – maxillary artery
S – superficial temporal artery
21
Q
How many anterior ciliary arteries are there
A
7
lateral rectus has only a single anterior ciliary artery,
22
Q
Where is the watershed area of retinal blood supply?
A
inner nuclear layer.
23
Q
Choroidal vs Retinal blood flow rate
A
Choroidal high flow rate, retinal low flow rate more O2 exchange
24
Q
Where is Wieger’s ligament found?
A
connects the anterior hyaloid face to the posterior lens capsule. 8–9 mm in diameter.
Its adherence to the posterior capsule becomes weaker with age. Intracapsular cataract surgery in young patients almost invariably leads to vitreous loss because of the adherence of Wieger’s ligament.
25
Length of cannaliculi tear ducts
2mm vertical segment followed by an 8 mm horizontal segment
26
Where is the lamina fusca found in relation to the scleral stroma
deep to the scleral stroma
27
Where is the sclera thinnest and thickest
thinnest behind the insertions of the extraocular muscles (0.3–0.4 mm) and thickest posteriorly near the optic nerve
28
What makes up the anterior boundary of the pterygopalatine fossa
Posterior surface of maxilla
29
What makes up the posterior boundary of the pterygopalatine fossa
Sphenoid including pterygoid process and greater wing
30
What makes up the superior boundary of the pterygopalatine fossa
Sphenoid at the junction of the body and greater wing
31
what makes up the inferior boundary of the pterygopalatine fossa
Pyramidal process of the palatine bone, open to palatine canals
32
what makes up the medial boundary of the pterygopalatine fossa
Vertical plate of the palatine bone
33
what makes up the lateral boundary of the pterygopalatine fossa
Open to the infratemporal fossa via the pterygomaxillary fissure
34
Where do the right and left common carotid arteries originate from
left- directly from the aortic arch,
right- brachiocephalic trunk divides into the right common carotid and right subclavian arteries.
35
What are the locations of the pigmented and non pigmented layers of the ciliary epithelium
inner non-pigmented layer and an outer pigmented layer arranged apex to apex
36
Sites on globe vulnerable to rupture
* Where the sclera is thinnest: at or just posterior to the insertion of the rectus muscles;
* At the corneoscleral junction (limbus);
* At the site of previous surgical incisions.
37
Anterior and Posterior chamber aqueous volume (Anterior segment)
250 microlitres
60 microlitres
38
Are choriocapillaris fenestrated
consists of relatively wide-bore capillaries. Unlike the larger vessels in Haller’s and Sattler’s layer, the endothelium is fenestrated rendering it permeable to large molecules including fluorescein.
39
What percentage of glucose is made in the lens by anaerobic glycolysis
Only lens epithelial cells possess mitochondria and so this is the only place in the lens where the citric acid (Krebs) cycle can occur. Anaerobic glycolysis accounts for approximately 80% of glucose consumption in the lens. The end products of this are lactic acid, which diffuses out into the aqueous, and adenosine triphosphate (ATP).
40
Function of matrix metalloproteinases
degrade extracellular matrix, are involved in both the maintenance of normal framework (principally MMP-2) and remodelling following injury.
41
How are RPE cells joined to each other
tight junctions
42
Where are fibrillins found
crucial component of the lens zonules and are also found in the lens capsule, the vitreous, and the stroma of most ocular tissues.
43
What condition results in mutation to fibrillin 1 gene
Marfan's syndrome
44
Does ELISA use radioisotopes
No
45
Can ELISA be both quantitative and qualitative
Yes
46
What happens during photoisomerization to 11 cis retinal
Converted to all trans retinal
47
Where is All-trans retinal is converted to all-trans retinol
in the photoreceptor outer segment before being transported to the retinal pigment epithelial cells, where it is reconstituted into the 11-cis retinal isoform (an isoform of vitamin A derived from carotenoids).
48
At which synaptic junction is glutamate used
synapses between the photoreceptors and bipolar and horizontal cells. This occurs in the outer plexiform layer following phototransduction.
49
What is the diameter of actin
7mm
50
Function of actin in cells
important component of the cytoskeleton, cell motility, cell division, cell–cell interactions, contractility and the interaction of transmembrane and cytoplasmic proteins.
51
Which neural layer derives the EOM and Schlemm canal
Mesoderm
52
When does the sphenoid sinus develop
2-3 years after birth
53
Which sinuses are the first to appear
Maxillary sinus
54
When does the hyaloid vasculature develop in the baby
between the 3rd and 8th week along with the primary vitreous.
55
When does hyaloid vessels, the tunica vasculosa lentis and the primary vitreous begin to atrophy
From 18 weeks
56
What is the remnant structure once hyaloid vessels, the tunica vasculosa lentis and the primary vitreous begin to atrophy
Cloquet’s canal is formed.
57
When does blood flow in the hyaloid artery stop
30 weeks
58
Which mutation causes Aniridia
PAX-6 mutations on chromosome 11.
Autosomal dominance inheritance
59
What is Gillespie syndrome
A rare form of aniridia is Gillespie syndrome, which is usually autosomal recessive and associated with cerebellar ataxia.
60
What is the order of size of chromosomes from 1 to 22
Chromosomes are numbered in decreasing order of size, and so chromosome 6 is bigger than 13.
61
What are p and q arms of the chromosome
p short
q long
62
What is inversion in genetics
involve two breaks in one chromosome, with 180° inversion of the segment. This interferes with chromosome pairing at meiosis and results in unbalanced gametes.
63
What is the Hardy Weinburg equilibrium
describes the constancy of gene frequencies in a population from one generation to the next. For a gene with two alleles, it is expressed as:
p2 + 2pq + q2 = 1
The Hardy–Weinberg equilibrium can apply regardless of whether a condition is X-linked or autosomal.
64
Ocular associations of Down's syndrome
keratoconus, myopia (and its associated risks including retinal detachment), cataract and Brushfield’s spots on the iris.
65
Where is the VHL gene found
chromosome 3. Autosomal dominant
66
Features of VHL
Retinal angiomata (also known as capillary haemangiomata) are the cardinal ocular feature. Cerebellar haemangioblastoma is also a cardinal feature of VHL but not an ocular one. Other non-ocular features include renal cell carcinomas and phaeochromocytomas.
67
Difference between metacentric and acrocentric chromosomes
Metacentric- centromeres located centrally on the chromosome, giving rise to two arms of roughly equal length
Acrocentric- centromere near one terminal end, giving rise to a short arm that
is difficult to observe.
68
Where is majority of complement produced
in the liver
69
How is the complement classic pathway activated
by antibody–antigen binding, and by acute phase proteins such as CRP
70
How is the alternative complement pathway triggered
binding of C3b to factor B on the surface of an organism or foreign material.
71
Which complement make up MAC
C5b-6-7-8 complex binds to C9, causing cell death by osmolytic lysis
72
Function of perforins and granzymes produced by cytotoxic T cells
perforins- create a channel in the membrane,
granzymes- induce apoptosis.
73
Which interferon can stimulate cells to express MHC class 2 molecules
interferon-γ can induce certain endothelial and epithelial cells
74
The peptides expressed by MHC 2 molecules are they intra or extracellular
principally from the extracellular environment, having been taken up by the cell and degraded in endosomes.
75
What is the VEP a test of
the electrical response of the visual cortex to a changing visual stimulus and thus is an objective test of the visual pathways.
76
Examples of single stranded RNA virus
Influenza A,
coxsackie
measles
77
Examples of Double stranded DNA virus
Adenovirus
78
What are Owl’s eye inclusion bodies are a specific histopathological sign of
CMV. detected on light microscopy in haematoxylin and eosin (H&E) stained preparations
Cytoplasmic- RNA viruses
Nuclear- DNA viruses
79
What are Cowdry type A inclusion bodies a sign of
nuclear and can be seen in herpes simplex, varicella zoster and sometimes cytomegalovirus infection.
80
What complement pathway do endotoxins activate
Alternative pathway- derived from the cell wall of Gram-negative bacteria
81
What genus is Acanthamoeba
single-celled eukaryotic micro-organisms
They are also often described as protozoa
82
Which acanthamoeba causes keratitis
Acanthamoeba polyphaga
83
Which forms do Acanthamoeba exist in
* Active trophozoites, which produce destructive enzymes to penetrate the cornea; and
* Metabolically inactive cysts, which are very hardy and survive unfavourable conditions including chlorination of water.
84
Which IgE does Toxocara stimulate
IgE
85
What does a Porro prism do to the image
Image deviated 180
Image inverted but not transposed left to right
86
What does a Dove prism do to the image
– Image not deviated
– Image inverted but not transposed left to right
87
What does a Wollaston prism do to the image
Incident beam of light split into two polarised emergent beams at a fixed angle without dispersion
88
SRK Formula
A-2.5(AL)-0.9(K)
89
Magnifying factor of a 60D lens
1.15
90
Magnifying factor of a 66D lens
1.00
91
Magnifying factor of a 78D lens
0.93
92
Magnifying factor of a 90D lens
0.76
93
Radii of curvature of the anterior and posterior lens surfaces
anterior 7.7mm
posterior 6.8mm
94
Where is the Argon Blue laser beam absorbed in the eye
absorbed by xanthophyll in the inner and outer plexiform layers of the macula and therefore should not be used to treat lesions in this area.
95
Wavelength of Nd YAG laser
1064nm
96
Properties of Image 1,2,3 Purkinje images
erect virtual images as they arise from convex reflecting surfaces
97
Properties of Image 4 Purkinje image
inverted real image as it is the reflection from a concave reflecting surface
98
Is the anterior corneal curvature steeper centrally than peripherally
Yes- reduces spherical aberration
99
Does the lens nucleus have a higher refracting power than the periphery
Yes- reduces spherical aberration
100
What type of lens is a Hruby lens
Planoconcave lens
101
Power of a Hruby lens
-58.6 dioptres
102
What cylinder is needed to correct WTR astigmatism
Positive at 90 degrees. or negative cylinder at 180°
103
What cylinder is needed to correct ATR astigmatism
Positive at 180 degrees or negative cylinder at 90 degrees
104
What factors determine angle of deviation of a prism
angle of incidence of the light ray,
the refracting angle of the prism
the refractive index of the prism material.
105
What are Flexner–Wintersteiner rosettes
tumour cells arranged around a central lumen. The cells resemble primitive photoreceptor cells on electron microscopy. They are characteristically seen in retinoblastoma
106
What are Homer–Wright rosettes
represent neuroblastic differentiation and are relatively non-specific- can be seen in Retinoblastoma
107
What are fleurettes
represent photoreceptor differentiation in Retinoblastoma
108
Which other conditions can Flexner–Wintersteiner rosettes be seen in
pineoblastomas and medulloepitheliomas
109
Which age does keratoconus stabilise by
early to mid-thirties
110
What are Fleishcher rings in keratoconus
result of iron deposition in the basal epithelial layers at the base of the cone
111
Does Behcets disease cause a granulomatous inflammation
NO
112
Features of worst prognosis in choroidal melanoma
epithelioid cells
The most important cytogenetic predictors of mortality and metastasis in choroidal melanoma are:
monosomy of chromosome 3 and partial duplication of 8q.
Older age, large tumour size and extrascleral extension are further poor prognostic factors
113
What type of rejection is a corneal graft rejection
Type 4
114
Risk factors for corneal graft rejection
* Young age
* Repeat grafts
* Large grafts
* Preoperative stromal vascularisation
* Loose or broken sutures
* Active inflammation
115
What type of receptor is the nicotinic acetylcholine receptor
Ligand gated ion channel
116
What is The main barrier to intraocular penetration of topical drugs
Corneal epithelium. Tight junctions between the superficial cells form a hydrophobic barrier
117
What does a higher pH cause in terms of corneal permeability
increases its intraocular penetration as well as its systemic absorption
118
How do corticosteroids reduce the chronic inflammatory response
decrease fibroblast function but that they also impair wound healing.
119
How does Edrophonium work in the tensilon test
inhibits acetylcholinesterase, therefore reducing the breakdown of acetylcholine
in the synaptic cleft.
120
How does 5-FU Work
Fluorinated pyrimidine analogue which impedes DNA synthesis
121
How does Mitomycin C work
Alkylation agent which crosslinks DNA
122
Where in the cell cycle does 5-FU work
S phase
G2
123
Where in the cell cycle does Mitomycin C work
Non cell cycle specific
124
Is 5FU more toxic than Mitomycin to the corneal epithelium
YES
125
How do amphetamines work
Increased noradrenaline release
126
How does Cocaine work
Decreased Noradrenaline uptake
127
How does MDMA work
Increased release of monoamine neurotransmitters (including noradrenaline), inhibition of serotonin reuptake
128
Wavelengths of peak spectral sensitivity for Blue, green and red cones (SML)
Blue (S)- 445
Green (M)- 545
Red (L)- 570
129
Commonest congenital colour defect
deuteranomaly, which occurs in 5% of men and 0.3% women.
130
Which chromosome is the gene for red and green cones located on
X chromosome
131
Which chromosome is the gene for blue cones located on
7
132
What does somatostatin do to growth hormone
Prevents release
133
Osmolarity units
Per litre of solution
134
Osmolality units
Per kg of solvent
135
Normal osmolality of plasma
280–305 mosmol/kg.
136
4 principal proteins in lacrimal gland secretions
lysozyme,
lactoferrin,
lipocalcin
secretory IgA
137
Which glycosaminoglycan is found in vitreous
Hyaluronan
138
Where does aqueous drain into via the uveoscleral route
passes via the suprachoroidal spaces into the choroidal circulation
139
Where are the cell bodies of the nerves of the optic radiations are located
LGN
140
What is CSF highly constituent in
Higher concentrations of chloride, magnesium and hydrogen ions
141
Examples of parametric tests
Student's t test, the z test and analysis of variance (ANOVA)
142
Examples of non parametric tests
χ2 test, Fisher's exact test, and the Mann–Whitney (Wilcoxon rank sum) test.
