Eye and Ear Anatomy MCQs

Anatomy · 32 free questions with answers & explanations.

1. The oval window of the middle ear is in contact with which structure of the inner ear?
2. Which muscle of the ciliary body contracts to allow accommodation (near focus) in the eye?
3. A patient with middle ear infection develops sudden onset of ipsilateral facial palsy and loss of taste on the anterior two-thirds of the tongue without any hearing loss. The chorda tympani nerve was most likely damaged at which anatomical point?
4. A premature neonate is diagnosed with retinopathy of prematurity (ROP). The pathological process begins at the junction of vascularised and avascular retina. Which retinal layer supplies the inner retina with oxygen via diffusion from retinal vessels, while the outer retina depends on the choroidal circulation?
5. The organ of Corti is the peripheral receptor for hearing. Which specific cell type synapses with the auditory nerve (spiral ganglion neurons) and what is the approximate ratio of inner to outer hair cells in the cochlea?
6. The blood supply of the retina comes from two sources. The outer layers (photoreceptors) are avascular and depend on which nutritional source?
7. The cochlear duct (scala media) is filled with endolymph and houses the organ of Corti. The endolymph has an unusually high potassium concentration (similar to intracellular fluid). This endocochlear potential (+80 mV) is maintained by which structure?
8. The optic nerve (CN II) is surrounded by meningeal sheaths (pia, arachnoid, dura) and a subarachnoid space continuous with the cranial subarachnoid space. This explains a clinical sign seen in raised intracranial pressure. What is this sign?
9. During vitreoretinal surgery, the surgeon identifies the ora serrata. This structure marks the boundary between which two zones, and what is the clinical significance of the peripheral retina near this boundary?
10. Which cell type in the spiral organ of Corti converts mechanical vibrations (shearing of stereocilia) into electrical signals, and what opens the ion channels responsible for depolarization?
11. The macula lutea of the retina provides high-acuity color vision because of which histological feature?
12. The hair cells of the organ of Corti are arranged with inner and outer hair cells separated by pillar cells. The outer hair cells differ from inner hair cells by which property that is crucial for cochlear amplification?
13. A patient with chronic suppurative otitis media (CSOM) with cholesteatoma undergoes mastoidectomy. Intraoperatively, the surgeon identifies the second genu (bend) of the facial nerve in the mastoid segment. Which structure lies immediately lateral to the facial nerve at the level of the second genu?
14. In the optic chiasm, the specific fiber arrangement determines the nature of visual field defects. A craniopharyngioma compressing the inferior aspect of the optic chiasm first damages which fiber group?
15. A patient develops a traumatic vitreous haemorrhage with no retinal tear. On slit-lamp examination, Shafer's sign (tobacco dust) is absent. Which anatomical structure attaches the vitreous most firmly to the retina and is the last to separate during posterior vitreous detachment?
16. Presbyacusis (age-related hearing loss) primarily affects high-frequency sounds first. Which part of the cochlear basilar membrane is responsible for high-frequency sound perception, and what is its anatomical characteristic?
17. The spiral organ of Corti, the receptor organ for hearing, sits on the basilar membrane within the scala media. The endolymph that bathes its stereocilia has a unique ionic composition. Which ion is present at an unusually HIGH concentration in endolymph (compared to most extracellular fluids) and is essential for the mechanoelectrical transduction current?
18. The optic canal transmits the optic nerve (CN II) and ophthalmic artery. Which structure separates the optic canal from the superior orbital fissure?
19. The fovea centralis of the retina achieves the highest visual acuity because of which specific histological arrangement?
20. The annular ligament (annulus fibrosus of the stapes) attaches the footplate of the stapes to the oval window (fenestra vestibuli). Otosclerosis preferentially involves which anatomical site of the temporal bone, and how does this impair conductive hearing?
21. The cochlear (round window) and vestibular (oval window) windows connect the middle ear to the inner ear. The cochlear duct (scala media) is bounded superiorly by Reissner's membrane and inferiorly by the basilar membrane. High-frequency sounds are transduced at which part of the basilar membrane?
22. The endolymph in the membranous labyrinth has an ionic composition similar to which fluid, and the perilymph is similar to which fluid?
23. The blood supply to the retina has a dual source. The outer layers (photoreceptors) depend entirely on which vascular structure, and which clinical condition results from its impairment?
24. The endolymph of the membranous labyrinth has a unique ionic composition (high K+, low Na+) resembling intracellular fluid. It is produced by which structure and absorbed by which structure?
25. The spiral ligament and stria vascularis of the cochlea are responsible for maintaining the high potassium (K+) concentration of endolymph. The stria vascularis generates the endocochlear potential of approximately +80 mV. Damage to the stria vascularis (as in Meniere disease or aminoglycoside ototoxicity) affects hearing by:
26. The blood supply to the outer layers of the retina (photoreceptors and outer nuclear layer) is derived from which source, and why is this relevant in retinal detachment?
27. The semicircular canals detect angular acceleration. The lateral (horizontal) semicircular canal ampulla contains hair cells whose kinocilia are oriented in which direction, and what is the physiological consequence of ampullopetal endolymph flow in this canal?
28. The organ of Corti sits on the basilar membrane within the scala media (cochlear duct). Hair cells transduce mechanical vibration into electrical signals. The inner hair cells (IHC) versus outer hair cells (OHC) have which different functional roles?
29. The organ of Corti contains inner and outer hair cells. Which structure carries afferent signals from the inner hair cells to the central auditory system?
30. The ciliary ganglion lies in the orbit and provides postganglionic parasympathetic fibers. Its postganglionic fibers travel to the eye via:
31. The organ of Corti rests on the basilar membrane of the cochlea. According to the 'place theory' of hearing, high-frequency sounds stimulate which region of the basilar membrane?
32. The fovea centralis of the retina is the area of highest visual acuity. Its high acuity is due to: