This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Special Senses, Subject name: Physiology
Depolarisation in hair cells of organ of coi occurs due to: 
Select and explain. 
A. Movement of basilar membrane, B. Movement of taller stereocilia toward the smaller ones, C. Influx of Na+, D. None of the above
A: Movement of basilar membrane
Answer: A: Movement of basilar membrane 
Explanation: Depolarisation in hair cells of organ of coi occurs primarily due to movement of basilar membrane TIP LINK THEORY: When the shoer stereocilia are pushed toward the taller ones, the channel open time is increased. K+, the most abundant cation in endolymph, and Ca2+ enter the channel and induce depolarization. Mainly K+ influx in the hair cells causes depolarisation.