Assertion : During micturition, urine is prevented from flowing back into the ureters.\ Reason : Ur

Question

Assertion : During micturition, urine is prevented from flowing back into the ureters.\ Reason : Urethral sphincters contract during micturition.\

Professor PC Thomas Classes · Answer

(c) : The micturition is the process of evacuation of the formed urine from the bladder time to time. Urine is prevented from flowing back into the ureters, because the terminal part of each ureter passes obliquely through the bladder wall and is consequently closed due to compression by the contracting bladder muscles. When enough urine has accumulated in the bladder to distend the bladder and raise its pressure sufficiently, a spontaneous nervous activity (reflex) is initiated; this causes the smooth muscles on the bladder wall to contract and the urethral sphincters, which guard the urethra, to relax. Urine consequently flows from the bladder through the urethra to the exterior.