1. The electro-oculogram:
a. measures the standing potential between the front and the
back
of the eye
b. the normal response in a dark adapted state is twice as big as
that in light
c. is of particular use in the diagnosis of Best's disease
d. is of value in early stages of most retinal degeneration
e. the normal range of Arden values is between 175 and 220%
2. The primary absorbers of visual light in the retina and choroid
are:
a. retinal ganglion cells
b. macular xanthophyll
c. melanin
d. photoreceptors
e. haemoglobin
3. The blood retinal barrier:
a. the outer blood retina barrier is formed by RPE cells and
their
junctions
b. the basement membrane of the retinal capillaries is a major
component of the inner blood retina barrier
c. the blood retinal barrier is typically defective in the immediate
peripapillary region
d. the retinal vascular endothelial cells can actively transport fluid
and
anions from the extracellular space fo the retina
into the circulation
e. inhalation of 10% carbon dioxide causes rapid breakdown of the
inner blood retina barrier
4. Human aqueous contains higher levels than plasma of :
a. zinc
b. chloride
c. ascorbic acid
d. hyaluronidase
e. bata-crystallin
5. Saccadic movements of the eye:
a. are typically present in infants at birth
b. develop in infants before smooth pursuit movements appear
c. have a velocity of about 500 degrees per second
d. originate in the ipsilateral frontal lobe of the brain
e. act independently of the vestibular system
6. Visual pigment dynamics:
a. molecules of rhodopsin are on the surface of the lipid bilayer
of
the disc membrane
b. 11 cis-retinal fits into hydrophobic cleft in visual pigment molecule
c. visual excitation initiation occurs by isomerisation of 11 cis-retinal
into all-trans retinol
d. opsin is responsive to bright light stimulation
e. during photoreceptor renewal new opsin molecules are added to
the outer segments
7. The intraocular pressure can fluctuate:
a. seasonally
b. diurnally
c. with eye movements
d. in optic neuritis
e. with fluid intake
8. The tear film:
a. contributes to the refractive function
b. is stabilized by the mucus layer
c. is partly formed form the Meibomian gland
d. is 100um thick
e. its normal break-up time is 5-15 seconds
9. Concerning colour vision and its assessment:
a. the axis of colour vision loss in protonopia using the
Farnsworth-Munsell 100 Hue test passes through the
pigments
red and green on the colour circle
b. the Ishihara pseudo-isochromatic plates can be used to detect
tritanopia
c. the Nagel-anomaloscope is used to detect red/green colour
defects
d. the Farnsworth Panel D 15 test relies on colour confusion across
the colour circle for the detection of an abnormality
in colour vision
e. the Lanthony desaturated Panel D 15 test is less sensitive than
the
Farnsworth Panel D15 test
10. In the ageing lens:
a. there is a decrease in insoluble albumin
b. there is an increase in heavy molecular weight crystallin
c. is aggregation of a-crystallin
d. there is a decrease in b-crystallin
e. there is an increase in protein soluble in urea
11. In the first stages of bleaching of rhodopsin the following
are formed:
a. opsin
b. all trans-retinal isomers
c. 11 cis-retinal isomers
d. intermediate products including metarhodopsin
e. vitamin A
12. Accommodation:
a. is abolished by sympathomimetic drugs
b. produces an increased curvature of the anterior surface of the lens
c. is dependent on elasticity of the lens capsule
d. is regulated with the help of chromatic aberration
e. is essential for appreciation of stereopsis
13. The RPE cells:
a. transport retinol binding protein from blood to subretinal
space
b. esterify and store excess retinol
c. are independent units and do not communicate electrically
or metabolically with each other
d. are secured laterally to each other by tight junction
e. dehydrate the subretinal space and create forces binding
themselves to neurosensotry retina
14. The study of eye movements has shown:
a. saccadic movements have a latency of about 200 msec
b. smooth pursuit movements have a maximum velocity of about 40
degrees per second
c. smooth pursuit movements cannot be executed without stimulus of
target motion
d. the inferior colliculus is important centre for visuomotor processing
e. flocculus has a role in adjusting the amplitude of the
vestibulo-ocular reflex
15. Stereopsis is produced by:
a. horizontal retinal disparity
b. an intact corpus callosum
c. polarized light
d. microsaccadic oscillations
e. Fox-Talbot effect
16. In relation to action of light on the eye:
a. equal amounts of radiant energy provide equal visual responses
irrespective of wavelength
b. human has a maximum sensitivity at 453 nm in bright light
c. in dark adaptation the initial phase is attributed to retraction
of
processes of the RPE
d. the retina cannot dark adapt if there is damage to the macula
e. it takes 7 photons to evoke a visual sensation in a single rod
17. The cones:
a. are responsible f or colour vision
b. are more sensitive to light than rods
c. are associated with a higher visual acuity than rods
d. have their function more impaired than rods by vitamin A
deficiency
e. are longer and thinner in the peripheral retina than in the central
retina
18. During accommodation for near:
a. the spherical aberration of the eye increases
b. the ciliary muscle relaxes
c. the field of vision decreases
d. the amount of light entering the eye increases
e. the thickness of the lens increases
19. With respect to motor neurones:
a. each a motor neurone supplies
a single muscle fibre
b. those motor neurones which take part in spinal reflexes are not
involved in voluntary movements
c. when two reflexes which reinforce each other are elicited
together, their joint effect may be greater than
the sum of their
individual effects
d. when two reflexes which reinforce each other are elicited together
their joint effect may be less than the sum of their
individual
effects
e. when a muscle is activated its b motor
neurones usually fire as
well as its a-motor neurones
20. With respect to sensory pathways:
a. receptive field properties of a sensory neurone define the
patterns of stimulation to which it responds best
b. lateral inhibition contributes to the receptive field properties
of
neurones in visual, auditory and somatosensory pathways
c. neurones in dorsal columns have clearly defined receptive fields
d. all sensory fibres entering the spinal cord cross the midline within
a few segments of point at which they enter
e. sensory neurones which are involved in spinal reflex arcs also
contribute to ascending sensory pathways
21. With respect to CNS organization:
a. most sensory pathways relay in the thalamus on their way
to the
cortex
b. sensory fibres enter the spinal cords by the dorsal roots
c. most motor pathways synapse on interneurones in the spinal cord
d. the left hand side of the brain receives information mainly from
the
left hand side of the body and vice versa
e. cell bodies of spinal motor neurones lie outside the spinal cord
22. Compliant of lungs:
a. may be expressed as volume change per unit change in
intrapleural pressure
b. is greater if the lung is stiff
c. is indirectly proportional to surface tension forces in the lungs
d. is affected more by surface tension forces than elastic recoil at
low lung volumes
e. is dependent upon lung volume
23. Ventilation is stimulated by:
a. fall in arterial oxygen pressure acting on central chemoreceptors
b. increased pH of arterial blood
c. increase pH of cerebrospinal fluid
d. interruption of the brain stem at the junction between the
spinal
cord and the medulla oblongata
e. excitation of mechanoreceptors in the limb joints
24. Which of the following alone will enable determination of the
plasma volume in
the body:
a. Evan's blue
b. radioactive sodium
c. haematocrite
d. red cell count
e. deuterium oxide
25. The pupil:
a. is dilated by the nicotinic action of atropine
b. is constricted by a blocking action of
thymoxamine
c. is dilated by the muscarinic action of cocaine
d. is constricted by 0.1% pilocarpine in Adie's pupil
e. demonstrates denervation sensitivity in upper motor neurone
Horner's syndrome
26. The following drugs give rise to impairment of accommodation:
a. pilocarpine
b. atropine
c. thymoxamine
d. phenylephrine
e. major tranquillizers
27. In administration of ophthalmic preparations:
a. acetazolamide should be avoided in patients with renal calculi
b. timolol maleate is a selective b blocker
c. systemic side effects of pilocarpine drops are dryness of mouth
and lack of sweating
d. gentamicin sulphate has no toxic effects on the cornea
e. eumovate drugs have less effect on IOP than dexamethasone
0.1%
28. Systemically administrated chloroquine:
a. is safer than hydroxychloroquine at equivalent dose
b. can cause corneal depositions of the drug
c. causes reversible toxic maculopathy
d. can cause posterior subcapsular cataract
e. causes abnormal dark adaptation
29. Which of the following statement is true:
a. dichlorphenamide is a carbonic anhydrase inhibitor
b. physostigmine is a cholinesterase inhibitor
c. cocaine eyedrops cause miosis
d. physostimgine eyedrops cause miosis
e. atropine is an anticholinergic drug
30. Recognized adverse effects of systemic carbonic anhydrase inhibitors
are:
a. anorexia
b. depression
c. increased libido
d. blood dyscrasiaa
e. urolithiasis
31. Acetazolamide causes:
a. metabolic acidosis
b. hypernatraemia
c. hyperkalaemia
d. renal calculi
e. inhibition of carbonic anhydrase
32. When applied topically to the eye, anticholinesterases:
a. relax the sphincter pupillae muscle
b. cause conjunctival hyperaemia
c. contract the ciliary muscle
d. raise the IOP
e. may produce systemic effect
33. H--receptor blockers:
a. have an arousing action in the CNS
b. are used as anti-emetics
c. include mepyramine
d. may have muscarinic receptor blocking action
e. prevent histamine induced gastric secretion
34. The following drugs may aggrevate or cause gastrointestinal
ulceration:
a. aspirin
b. paracetamol
c. codeine phosphate
d. phyenylbutazone
e. indomethacine
35. At the adrenergic synapse, the concentration of noradrenaline
in the synaptic
cleft is:
a. decreased by MAO inhibitors
b. increased by noradrenaline reuptake blockers
c. increased by partial agonist of noradrenaline receptors
d. increased by noradrenaline receptor blockers
e. mainly controlled by activity of the enzyme COMT
36. Renal clearance of acidic drugs may be delayed by:
a. alkalinizing the urine
b. administration of probenicid
c. their displacement from plasma protein binding sites
d. sequestration in fat
e. respiratory acidosis
37. Clinically significant anticoagulant effect s of warfarin are
diminished by
barbiturates:
a. barbiturates form chemical complexes with warfarin
b. induction of liver enzymes
c. competition for plasma protein binding sites
d. competition for renal secretion
e. barbiturate reduces the gastrointestinal absorption of warfarin
38. Case-control study:
a. is an example of interventional epidemiological study
b. provides knowledge concerning how much disease exists in a
community
c. requires vigorous study design and data analysis
d. must be performed in population of more than one million
e. is usually prompted by a descriptive study
39. The respiratory system:
a. the vital capacity is the maximal volume to which lungs
can expand
b. the functional residual capacity is the expired residual volume
plus
the residual volume
c. Herring-Breuer reflex is transmitted via the tractus solitarius
d. the blood PCO2 has more an effect on the pH of the CSF than
the blood pH
e. the chemoreceptors for control of respiratory activity are located
in the carotid bodies
40. Electrolytes:
a. bicarbonate is present intracellular and extracellular
b. the major extracellular ion is chloride
c. intracellular protein functions as a cation
d. the distribution of Ca2+ between intracellular and extracellular
fluid is influenced by membrane bound enzyme.
e. ammonium is the main buffer in the serum