Paper 1 Flashcards
(155 cards)
1
Q
In the superior orbital fissure which nerves pass outside the common tendinuous ring
A
Lacrimal
Frontal
Trochlear
NERVES!
2
Q
Horizontal and vertical diameter of the cornea
A
H- 11.7
V- 10.6
3
Q
What is diploe in bones
A
Layers of compact bone are separated by a layer of spongy bone called diploe
4
Q
Where does the frontal sinus drain into
A
Middle Meatus
5
Q
Where does the Maxillary sinus drain into
A
Middle meatus
6
Q
Where does the Anterior and middle ethmoidal sinus drain into
A
Middle meatus
7
Q
Where does the Posterior ethmoidal sinus drain into
A
Superior meatus
8
Q
Where does the Sphenoidal sinus drain into
A
Sphenoethmoidal recess/superior meatus
9
Q
Where does the Nasolacrimal duct open into
A
Inferior meatus
10
Q
Where does anterior blepharitis occur
A
Anterior to the gray line. Around the lash margins, crusting and dryness
11
Q
Where do the meibomian glands lie in relation to the gray line
A
Posterior to the gray line
12
Q
What portions does the lacrimal gland consist of
A
orbital
palpebral
13
Q
What is the innervation of the lacrimal gland
A
1) Parasympathetic- lacrimatory nucleus of CN VII. Fibres travel via the nervus intermedius to the pterygopalatine ganglion then via maxillary nerve to zygomatic and zygomaticotemporal branches and finally via the lacrimal nerve to the gland
2) Sympathetic- from the superior cervical ganglion. Fibres travel in the nerve plexus surrounding the ICA then via the deep petrosal nerve to maxillary nerve. Then via zygomatic and zygomaticotemporal nerve branches and finally via the lacrimal nerve to the gland as the PNS
3) Sensory- From the lacrimal nerve which is a branch of trigeminal nerve V1
14
Q
EOM vs Skeletal muscle fibres
A
EOM:
Thin connective tissue including epimysium
Loosely packed muscle fibres
Large diameter fibres (10-40 microns) occupying centre and smaller fibres (5-15 microns) peripherally
Long muscle spindles providing feedback about muscle activity to CNS
EOM more vascular than skeletal muscle
15
Q
Structures passing through foramen spinosum
A
1) MMA
2) MMV
3) Meningeal branch of the mandibular nerve
16
Q
What does the foramen spinosum connect
A
connects the middle cranial fossa to the inferotemporal fossa
17
Q
Nerve branches of the facial nerve
A
Temporal
Zygomatic
Buccal
Mandibular
Cervical
TO ZANZIBAR BY MOTOR CAR
18
Q
Bleeding from meningeal arteries causes what kind of haematoma?
A
Extradural
19
Q
Which line represents termination of Descemet layer
A
Schwalbe line
20
Q
Which location is posterior lens capsule thinnest
A
Posterior pole
21
Q
Site of attachment of vitreous base
A
Peripheral retina and pars plana
22
Q
From innermost to outermost layers of RPE Bruch membrane
A
Basal lamina of RPE
Inner collagenous layer
elastin layer
outer collagenous layer
Basal lamina of choriocapillaris
23
Q
Point of insertion of lateral canthal tendon
A
Whitnall tubercle
24
Q
What is the sensory innervation of the iris
A
Long and short ciliary nerves derived from the nasociliary nerves
25
Posterior to anterior orientation of the optic canal
Inferolateral
26
What does the optic canal connect
Middle cranial fossa and orbital apex
27
Is the ciliary body AP length greater nasally or temporally
Temporally
28
Muscular layers of ciliary body from outer to inner
Outer longitudinal
Middle radial
Inner circular
29
What iris structure contributes to blood aqueous barrier
Non fenestrated iris capillaries with tight junctions and pericytes
30
Where is the minor arterial circle of the iris found
At the level of the collarette
31
Where do the lymphatics from the right side of the head and neck and the right arm drain into
common lymphatic duct-->right lymphatic duct--> Right subclavian vein
32
What lymphatic duct drains the rest of the body
Thoracic duct-->left subclavian vein
33
Where do the right and left subclavian veins drain into?
Brachiocephalic veins and SVC
34
Which blood vessel layer is fragmented in GCA
Internal elastic lamina
35
What does aqueous contain high levels of compared to plasma
Ascorbate
Lactate
36
What does aqueous contain lower levels of compared to plasma
Slightly lower level of bicarbonate
Lower levels of glucose and calcium
Much lower levels of albumin
37
In collagen synthesis what is transcription
DNA-->RNA
38
In collagen synthesis what is translation
RNA--> peptide formation
39
What is the basic repeating sequence of amino acid sequence in collagen
Glycine-X-Y
X is often proline
Y is often hydroxyproline
40
What is involved in post translational modification of collagen synthesis
Vitamin c dependent hydroxylation of the Y position amino acid
Glycosylation
Triple helix formation linked by covalent S--S bonds
41
What happens to collagen on excretion from the cell
Cleavage of terminal peptide chains making it insoluble
42
How is collagen modified extracellularly
Lysine oxidation
Formation of crosslinks
43
What are Matrix metalloproteinases
Zinc and calcium dependent endopeptidases which act as an enzyme cascade to degrade ECM
Examples: collagenases and gelatinases
44
Where are MMP's found
released by neutrophils in acute inflammation
found in normal tissues for growth, maintenance, repair and remodelling
45
How are MMP's kept in check
Endogenous inhibitors called TIMP
46
What is 90% of the lens protein called
Crystallins
47
Which growth factor stimulates differentiation of anterior lens epithelial cells into lens fibres
Fibroblast growth factor
48
What is the charge on glycosaminoglycans
Highly negatively charged. Polysaccharides consisting of long chains of repeating dissacharides. They are inflexible
49
How does the endothelial cell pump work
Na/K ATPase pumps sodium actively into AC.
Passive diffusion of potassium and chloride
50
Where is pericyte coverage the highest in the eye
In the retinal vessels with a frequency of 1:1 pericytes to endothelial cells due to maintaining high metabolic demands of the retina and requirement to maintain the blood retinal barrier
51
What do pericytes do?
Maintain the blood brain barrier regulating permeability.
Communicate with endothelial cells by paracrine signalling and direct contact
52
How does Aflibercept work?
Decoy receptor molecule for VEGF
53
How does Bevacizumab/Ranibizumab work?
Monoclonal antibody to VEGF
54
How do VEGF receptors work
Via intracellular tyrosine kinase activity
55
How long do rod photoreceptors take for the renewal cycle to be complete
9-10 days
56
Which embryological layer does the lens come from?
surface ectoderm
57
In which quadrant are colobomas typically located
Inferonasally
58
Are glycosaminoglycans hydrophilic or hydrophobic
Hydrophilic
59
Which muscles come from the first pharyngeal arch
Muscles of mastication (masseter, temporalis, lateral and medial pterygoid)
Mylohyoid
Tensor tympani, tensor veli palatini, anterior belly of digastric
60
Which muscles come from the second pharyngeal arch
Muscles of facial expression, stylohyoid, stapedius, posterior belly of digastric
61
Which muscles come from the third pharyngeal arch
Stylopharyngeus
62
Which muscles come from the fourth pharyngeal arch
Pharyngeal constrictors, levator palatini, cricothyroid
63
Which muscles come from the sixth pharyngeal arch
Intrinisc muscles of the larynx except cricothyroid
64
Which week are optic nerve fibres present from
Week 6-7
65
When does myelination of the optic nerve first start
Month 7- from the optic chiasm
66
When is myelination of the optic nerve complete
1 to 3 months of age in full term baby
67
Vitreous collagen type predominance
Type 2
68
Edwards syndrome trisomy
Trisomy 18
69
Patau Syndrome trisomy
Trisomy 13
70
Klinefelter syndrome trisomy
47 XXY
71
When are the introns removed from the mRNA sequence
Before leaving the nucleus
72
What is the aim of genetic linkage analysis
To discover how often 2 loci are separated by meiotic recombination. The probability of crossing over between 2 genetic loci on the same chromosome is proportional to the distance between them
73
What is the charge on histones
Histones have a HIGH POSITIVE CHARGE
74
Which amino acid are found in histones giving it the positive charge
Lysine
Arginine
75
Which type of DNA polymerase is the principal enzyme in mitochondrial DNA replication
DNA Polymerase gamma
76
Which corneal dystrophy is autosomal recessive
Macula corneal dystrophy- safe to assume all others are autosomal dominant
77
What layer of the cornea is affected in Reis- Buckler corneal dystrophy
Epithelial basement membrane.
Stains with Masson Trichrome
78
What can Reis Buckler corneal dystrophy manifest as
Recurrent corneal erosion syndrome and corneal opacification
79
Examples of gene therapy vectors
Viral vectors- Adenoviruses, Retroviruses, Adeno associated viruses, HSV
Non viral vectors- Liposomes and naked DNA in the form of plasmids
80
Which antibody is a potent activator of the complement system
IgM
81
Examples of antigen presenting cells
Macrophages
Monocytes
Dendritic cells
Some B cells
Activated endothelial cells
82
Which MHC class molecule is HLAB27 an example of
MHC class I
83
What electric potential does the EOG measure
Resting electric potential between the RPE (electrically negative) and cornea (positive).
A test of the function of the outer retina and RPE hence abnormal in conditions affecting RPE photoreceptor interface or conditions with generalised RPE disease
84
Does the patient need to be awake for EOG
Yes, needs a cooperative patient to move eyes horizontally
85
Which major conditions is the EOG affected in
Best vitelliform macula dystrophy
Acute Zonal Occult outer retinopathy (Azoor)
86
Commonest cause of endogenous exophthalmitis
Coagulase negative staph- Staph epidermidis
87
Culture for Mycobacterium TB
Lowenstein Jensen medium
88
How does Rifampicin work
Inhibits bacterial DNA dependent RNA polymerase
89
How does Chloramphenicol and Erythromycin work
Inhibit 50s subunit of bacterial ribosome inhibiting bacterial protein synthesis
90
How does Vancomycin and Cefuroxime work
Inhibit bacterial cell wall synthesis
91
Difference between Acanthamoeba trophozoites and cysts
Trophozoitesa are relatively sensitive to treatment
Cysts can take many weeks to eradicate
92
How does Botox work
Botulinum toxin A- Inhibits exocytosis of Acetylcholine from presynaptic receptor endplate
93
Example of nematodal infection
Toxoplasmosis
Toxocara
94
Which Toxocara are shed in dog faeces
Toxocara canis ova
95
Which Toxocara and Toxoplasma are shed in cat faeces
Toxocara cati ova
Toxoplasma gondii
96
What ocular features can Toxocara and Toxoplasma cause
White chorioretinal lesions
vitritis
Infection may be asymptomatic
97
What are the photometric units of illuminance
Lux measured in lumen/m squared
98
What are the radiometric units of irradiance
Watt/m squared
99
How to check the axis of a refractive correction using JCC
Handle of cross cylinder held in line with axis of trial cylinder
100
How to check the power of a refractive correction using JCC
The positive or negative cylinder marking on the cross cylinder is held in line with the axis of the trial cylinder
101
In what position are glass prisms meant to be held
Prentice position
102
In what position are plastic prisms meant to be used
Position of minimum deviation
103
What are the properties of the image formed by the plane mirror
Virtual erect laterally inverted
104
How to adjust the IOL power in ciliary sulcus lens
If normal AL- reduce power by 1 dioptre
If original bag dioptric power lens >28 reduce by 1.5 dioptre
If original bag dioptric power <17 reduce by 0.5 dioptre
105
Which stereoacuity tests requires glasses wear
Worth 4 Dot test
Titmus test- polarised glasses
106
Which stereoacuity test does not require glasses wear
Frisby testing
107
Does a patient's refractive error have a greater effect on direct or indirect ophthalmoscopy
Direct ophthalmoscopy
Myopia- smaller view
Presbyopia- Larger view
108
Magnification of direct ophthalmoscope
15x
109
Image formed by indirect ophthalmoscope
Real, Inverted vertically and horizontally
110
Image formed by direct ophthalmoscope
Erect image no lateral inversion
111
Galilean telescope image properties
Virtual erect magnified and at infinity
112
Type of lenses within the Galilean telescope
Convex objective lens
Concave eyepiece lens
separated by the difference of their focal lengths
113
Fluorescein light absorption and emission wavelength ranges
Absorption 495m
Emission 530nm
114
How does corneal stroma mainatain corneal clarity
Destructive interference
115
Features of NF1
Iris lisch nodules
Optic nerve glioma
Neurofibroma/plexiform neurofibroma
Phaeochromocytoma
116
Features of NF2
Acoustic Neuroma
Meningioma
Glioma
Ependymoma
117
Is NF autosomal dominant
YES!!
118
Which chromosome is the NF1 and NF2 gene on
NF1- 17
NF2- 22
119
Which condition are Dalen Fuch's nodules found in
Epitheloid cells (Activated macrophages) and lymphocytes between bruch membrane and RPE from granulomatous inflammation in SO and VKH
120
Which part of the eye do uveal melanomas occur in
Iris 8%
Ciliary body 12%
Choroid 80%
121
Does Haematoxylin bind to acidic or basic substances
Acidic structures- blue stain
eg nucleic acids
122
Does Eosin bind to acidic or basic substances
Basic substances- pink stain
eg Amyloid
123
Where are hard exudates found in the retinal layers
localised hypoperfusion leading to damage of the endothelial capillaries and breakdown of inner blood retinal barrier causing leakage of plasma into the OPL appearing as pale deposits
124
Where does corneal arcus lipid deposition occur
corneal Stroma
125
When can proliferative vitreoretinopathy occur
PVR common cause of failure post RD surgery.
Can occur in untreated RD
Contraction and phthisis bulbi can occur
126
What are first order kinetics of drug metabolism
Linear- rate is proportional to concentration of drug
127
What are zero order kinetics of drug metabolism
Non linear- metabolism rate of drug independent of concentration ( non linear)
128
What is the impact of lipid solubility on distribution of drug
Increases drug absorption and distribution eg by allowing diffusion across cell membranes and blood-retinal barrier
129
Side effects of ciclosporin
Nephrotoxicity
Tremor
Hirsuitism
Gingival hypertrophy
130
How does brimonidine work
Alpha 2 receptor agonist
131
Horner syndrome which fails to dilate with 4% cocaine
All horner lesion
132
Horner syndrome which fails to dilate with 1% hydroxyamphetamine
3rd order lesion
133
Horner syndrome which dilates with Apraclonidine 0.5% or 1%
All horner lesion
134
Horner syndrome which dilates with phenylephrine
3rd order lesion
135
Examples of Eicosanoids
Prostaglandins, Thromboxanes (Together termed prostanoids)
Leukotrienes
136
How do NSAIDs inhibit inflammation
inhibit cyclooxygenease and therefore synthesis of prostaglandins
137
On which receptors do prostaglandins exert their effect
GPCR
138
What impact does Thromboxane have on vessels
Eicosanoid which cause vasoconstriction and platelet aggregation
139
What do Eicosanoids do
Signalling molecules and inflammatory mediators .
Inflammatory response always involves prostanoid generation
140
Half life of Midazolam
1-3 hours. GABAa receptor agonists in CNS
141
Are histamine receptors GPCR's
YES!
142
Histamine H1 receptor activation effects
Activation of phospholipase C
Increased intracellular calcium concentration
Cause:
Increased vascular permeability
Vasodilation
CNS depressant
143
Histamine H2 receptor activation effects
Activation of adenylate cyclase and increase in cAMP
Cause:
Increased gastric acid production
Increased cardiac stroke volume
144
What does Chromaticity depend on
Hue
Saturation
Luminance
145
What is the Bezole Brucke effect
With increasing brightness eventually all hues appear yellow white whilst very low lumuinous hues appear achromatic
146
What is the maximal spectral sensitivity of green cones
535-550 nm
147
What happens in dark adaptation
Bipartite.
Initial rapid 5-10 mins increase in cone sensitivity and a slower period 15-30 mins where rods reach max sensitivity
148
How long does dark adaptation take
30 mins
149
What does Somatostatin do
Inhibits the release of growth hormone
150
Which process is thought to account in 80-90% aqueous production
Active secretion
Remainder by ultrafiltration
151
Which glycosaminoglycan is responsible for maintaining corneal clarity
Keratan sulphate
152
What are saccades
Rapid eye movements to change points of fixation
Voluntary or reflexive
Max velocity 900 degrees per second
153
What are smooth pursuits
Slow tracking movement to keep target on fovea
Voluntary movement
Max velocity 100 degrees per second
154
What is a type 2 error
Failure to reject the null hypothesis even though it is false i.e failing to detect a real difference
155
What is a type 1 error
null hypothesis is rejected when it is true i.e finding a difference when there is none
