True statements about EOG (electro-oculogram) include:
a. the EOG light-peak to dark-trough ratio is reduced in central retinal vein occlusion
b. the light peak of EOG is abnormal in Best's disease
c. the EOG light rise is produced by depolarization of the basal membrane of the retinal pigment
epithelium
d. all above

1 Answer

Answer :

all above

Related questions

Description : The retinal pigment epithelium (RPE): a. is sensitive to hypervitaminosis A b. isomerizes all-trans-retinal to 11-cis-retinol c. does not undergo mitosis in response to injury d. secrets the outer layer of the basal lamina that forms the Bruch's membrane.

Last Answer : isomerizes all-trans-retinal to 11-cis-retinol

Description : True statements about chloroquine include: a. is safer than hydroxychloroquine at equivalent dose b. can cause corneal deposition c. causes posterior subcapsular cataract d. chloroquine is bound to the melanin of the retinal pigment epithelium e. causes reversible toxic maculopathy

Last Answer : can cause corneal deposition

Description : The following are true about electroretinogram: a. the a-wave is produced by the photoreceptors b. the b-wave is produced by the ganglion cells c. c-wave is produced by the retinal pigment epithelium d. different light frequencies can be used to separate rod and cone respons

Last Answer : he a-wave is produced by the photoreceptors

Description : The following are true about electroretinogram: a. the a-wave is produced by the photoreceptors b. the b-wave is produced by the ganglion cells c. c-wave is produced by the retinal pigment epithelium d. different light frequencies can be used to separate rod and cone response

Last Answer : the a-wave is produced by the photoreceptors

Description : A patient of old standing diabetes mellitus noticed sudden muscae volitanes. On examination, the red reflex was dim, with no details of fundus could be seen. He might have: a. Non proliferative diabetic retinopathy b. Cystoid macular edema c. Vitreous hemorrhage d. Central retinal vein occlusion 

Last Answer : ANSWER: C 

Description : Night blindness is caused by: a. Central retinal vein occlusion b. Dystrophies of retinal rods c. Dystrophies of the retinal cones d. Retinal detachment

Last Answer : ANSWER: B

Description : A young patient with sudden painless loss of vision, with systolic murmur and ocular examination reveals a cherry red spot with clear AC, the likely diagnosis is: a. Central Retinal Artery Occlusion b. Central Retinal Vein Occlusion c. Diabetes Mellitus d. Branch Retinal Vein Occlusion  

Last Answer : ANSWER: A

Description : 100 days glaucoma is seen in: a. Central Retinal Artery Occlusion b. Branch Retinal Artery Occlusion c. Central Retinal Vein Occlusion d. Branch Retinal Vein Occlusion

Last Answer : ANSWER: C

Description : Haemoglobin SC disease: a. is common amongst Afro-carribean people b. does not show sickle cells in the blood film. c. causes severe anaemia d. causes retinal vein occlusion

Last Answer : causes retinal vein occlusion

Description : In retinal detachment, fluid accumulates between: a. Outer plexiform layer and inner nuclear layer. b. Neurosensory retina and layer of retinal pigment epithelium c. Nerve fiber layer and rest of retina. d. Retinal pigment epithelium and Bruch’s membrane.  

Last Answer : ANSWER: B 

Description : Regarding retinal metabolism: a. insulin is essential for the uptake of glucose by the retina b. anaerobic metabolism predominates c. the pigment retinal epithelium stores glycogen and supplies the need of the retina d. the demand of oxygen is met entirely by the central retinal artery

Last Answer : anaerobic metabolism predominates

Description : Retinal vein occlusion?

Last Answer : DefinitionRetinal vein occlusion is a blockage in the blood supply from the retina -- the light-sensitive tissue in the back of the eye.Alternative NamesCentral retinal vein occlusion; Branch retinal vein ... in all or part of one eyeSigns and testsTests to evaluate the retina include:Color visionE

Description : The following are true about electroretinogram (ERG): a. the a-wave has negative deflection b. a wave is generated by the retinal pigment epithelium c. amacrine cells are responsible for the oscillatory potential d. it is possible to separate the cone and rod ERG

Last Answer : t is possible to separate the cone and rod ERG

Description : The following are true about tight junction: a. it forms a barrier to water b. it is found in the blood-aqueous barrier of the ciliary body c. it is found in the blood-retinal barrier at the apex of the retinal pigment epithelium d. all above

Last Answer : all above

Description : The following cells contribute the wavefronts of the flash ERG: a. retinal pigment epithelium b. corneal endothelium c. photoreceptors d. ganglion cell

Last Answer : photoreceptors

Description : With regard to the blood retina barrier: a. the outer blood retina is formed by the retinal pigment epithelium cells and their junctions b. the blood retina barrier is typically defective in the ... fluid and anions from the extracellular space of the retina into the circulation d. all above

Last Answer : all above

Description : The retinal pigment epithelium cells: a. esterify and store excess retinol b. transport retinol binding protein from blood to subretinal space c. are secured laterally to each other by tight junction d. all above

Last Answer : all above

Description : The following structures are of ectodermal origin: a. the retina and its retinal pigment epithelium b. iris stroma c. the sclera d. the ciliary muscle e. the corneal stroma

Last Answer : the retina and its retinal pigment epithelium

Description : The cells of the retinal pigment epithelium: a. are of mesenchymal origin b. are shorter at the fovea than else where in the retina c. have intracellular melanosomes d. regenerate visual pigment e. form the inner outer blood-retina barrier

Last Answer : have intracellular melanosome

Description : The bright-flash ERG: a. comes only from the cones b. is generated in a fully dark adapted eye by the highest intensity of light c. can be used to assess the overall retinal integrity in the presence of media opacity d. is abnormal in patients with age-related macular degeneration

Last Answer : can be used to assess the overall retinal integrity in the presence of media opacity

Description : A male patient 30 years old with visual acuity of 6/6 in both eyes. Twelve hours ago he presented with drop of vision of the left eye. On examination, visual acuity was 6/6 in the ... : a. Raised intra cranial pressure b. Raised ocular tension c. Central retinal artery occlusion d. Optic neuritis

Last Answer : ANSWER: D

Description : Occlusion of the lower nasal branch of the central retinal artery results in one of the following field defects: a. Lower nasal sector field defect b. Upper nasal sector field defect c. Upper temporal field defect d. Lower temporal sector field defect

Last Answer : ANSWER: C  

Description : In Central retinal artery occlusion, a cherry red spot is due to: a. Hemorrhage at macula b. Increased choroidal perfusion c. Increase in retinal perfusion at macula d. The contrast between pale retina and reddish choroids  

Last Answer : ANSWER: D

Description : Assertion`:-` Cells of epithelium tissues rest on a thin basement membrane. Reason`:-` Basement membrane has both fibrous and basal lamina secreted by

Last Answer : Assertion`:-` Cells of epithelium tissues rest on a thin basement membrane. Reason`:-` Basement membrane ... D. If both Assertion & Reason are false.

Description : Commotio retinae is seen in: a. Concussion injury b. Papilloedema c. Central retinal vein thrombosis d. Central retinal artery thrombosis

Last Answer : a

Description : Neovascular glaucoma follows: a. Thrombosis of central retinal vein b. Acute congestive glaucoma c. Staphylococcal infection d. Hypertension

Last Answer : ANSWER: A 

Description : The electrophysiological effects of digitalis on Purkinje fibres include the following except: A. Enhancement of resting membrane potential B. Decrease in the slope of phase-0 depolarization C. Increase in the rate of phase-4 depolarization D. Abbreviation of action potential duration

Last Answer : A. Enhancement of resting membrane potential

Description : The following are true about the ERG: a. in infarction of the choroidal circulation the a-wave of the ERG is reduced or absent b. the ERG is always abnormal in patients with macular diseases c. ... can be used to isolate cone photoreceptors d. the b-wave of ERG is reduced in dark-adapted eye

Last Answer : the b-wave of ERG is reduced in dark-adapted eye

Description : Retinal artery occlusion?

Last Answer : DefinitionRetinal artery occlusion is a blockage of the blood supply in the arteries to the retina -- the light-sensitive tissue in the back of the eye.Alternative NamesCentral retinal artery occlusion; ... of the two large blood vessels in the neck (carotid artery disease)Disorder of high

Description : Good vision depends on adequate intake of carotene rich food. Select the best option from the following statements. (1) Vitamin A derivatives are formed from carotene. (2) The photopigments are embedded in the membrane discs of the inner ... (1) and (3) (c) (2), (3) and (4) (d) (1) and (2)

Last Answer : (b) (1) and (3)

Description : Good vision depends on adequate intake of carotene rich food : Select the best option from the following statements : (a) Vitamin A derivatives are formed from carotene (b) The photopigments are embedded in the membrane discs of the inner segment ... (a) and (c) (3) (b), (c) and (d) (4) (a) and (b)

Last Answer : (1) (a), (c) and (d)

Description : Which type of sleep apnea is characterized by lack of airflow due to pharyngeal occlusion? a) Obstructive Obstructive sleep apnea occurs usually in men, especially those who are older ... central sleep apnea, the patient demonstrates simultaneous cessation of both airflow and respiratory movements.

Last Answer : a) Obstructive Obstructive sleep apnea occurs usually in men, especially those who are older and overweight.

Description : True statements about the retinal blood flow include: a. the retina receives 5% of total ocular blood flow b. the retinal blood flow is mainly under the sympathetic control c. the ... are impermeable to ascorbate d. the pericytes control the contractile activity of the retinal blood vessels

Last Answer : the pericytes control the contractile activity of the retinal blood vessels

Description : True statement about dark adaptation include: a. there is a shift in peak spectral sensitivity from 555 nm to 505 nm with dark adaptation b. rods are more sensitive than cone during dark adaptation c. biphasic changes only occur in retina which processes both rods and cones d. all above

Last Answer : all above

Description : 8. Immediately after a trough, we would expect to have a/an a. peak b. recession c. recovery

Last Answer : c. recovery

Description : Which of the following phases describes the phase of business cycle that occurs after a trough and before a peak (a) Lag (b) Consolidation © Expansion (d) Contraction

Last Answer : © Expansion

Description : Pigment containing membranous extensions in some cyanobacteria are (a) pneumatophores (b) chromatophores (c) heterocysts (d) basal bodies

Last Answer : b) chromatophores

Description : What are the features for Human Retinal Pigment Epithelial Cells?

Last Answer : Human Retinal Pigment Epithelial Cells (HRPEpiC) are isolatedfrom human retina. HRPEpiC are cryopreserved at passage one anddelivered frozen. Each vial contains >5 x 10^5 cells in 1 mlvolume. HRPEpiC are ... fibronectin.HRPEpiC are negative for HIV-1, HBV, HCV, mycoplasma, bacteria,yeast and fungi.

Description : In the neurone: a. the magnitude of the action potential is dependent on the strength of the stimulus b. impulses can travel in both direction c. depolarization is accompanied by increased ... potassium ions d. during depolarization, the potential of the neurone changes from -70mV to +40mV

Last Answer : during depolarization, the potential of the neurone changes from -70mV to +40mV

Description : The following processes depend on changes in membrane conductance to Na and K. a. Action potential b. depolarization c. repolarization d. all of them

Last Answer : all of them

Description : The most probable mechanism of action of mebendazole is: A. Depolarization of membrane and spastic paralysis of the worm B. Hyperpolarization of membrane and flaccid paralysis of the worm C. Loss of ... inhibition of glucose uptake in the worm D. Tegument damage and leakage of contents of the worm

Last Answer : C. Loss of intracellular microtubules and inhibition of glucose uptake in the worm

Description : The most significant feature of the antiarrhythmic action of lignocaine is: A. Suppression of phase-4 depolarization in ventricular ectopic foci B. Prolongation of action potential duration C. Prolongation of effective refractory period D. Depression of membrane responsiveness

Last Answer : A. Suppression of phase-4 depolarization in ventricular ectopic foci

Description : Local anaesthetics block nerve conduction by: A. Blocking all cation channels in the neuronal membrane B. Hyperpolarizing the neuronal membrane C. Interfering with depolarization of the neuronal membrane D. Both ‘B’ and ‘C’ are correct

Last Answer : C. Interfering with depolarization of the neuronal membrane

Description : True statements about visual adaptation include: a. light adaptation takes longer than dark adaptation b. dark adaptation reaches its maximum in about 20 minutes c. in dark adapted eye, a higher intensity ... wear red goggles in the light adapt quicker in the dark than those who do not wear them

Last Answer : in dark adapted eye, a higher intensity of light is required to stimulate cones than rods

Description : 07. What is implied by «active transport»? a) Transport of drugs trough a membrane by means of diffusion b) Transport without energy consumption c) Engulf of drug by a cell membrane with a new vesicle formation

Last Answer : d) Transport against concentration gradient

Description : The following are true about ocular circulation: a. only 4% of the total blood supply to the eye goes to the retina b. the choroidal blood flow in normal people is ten times that of the grey mater ... and choroidal circulation d. a PaCO2 rise of 1 mm Hg induces a 3% rise in retinal blood flow

Last Answer : a PaCO2 rise of 1 mm Hg induces a 3% rise in retinal blood flow

Description : What controls the occlusion:. A. Teeth B. Receptors in periodontal membrane C. Proprioceptors D. Neuromuscular receptors E. TMJ F. All of the above

Last Answer : F. All of the above

Description : The effect of calcium ions on neurotransmitter release at synapses include: a. vesicular fusion b. tonic depolarization of the presynaptic neurone c. post-tetanic potentiation d. all above

Last Answer : all above

Description : Which of the statements given below is not true about formation of annual rings in trees? (a) Annual rings are not prominent in trees of temperate region. (b) Annual ring is a combination ... of tissue-early and late wood respectively. (d) Activity of cambium depends upon variation in climate.

Last Answer : a) Annual rings are not prominent in trees of temperate region