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

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. if both assertion and reason are true but reason is not the correct explanation of assertion.
C. if assertion is true but reason is false
D. if both assertion and reason are false.

Answer

C

Explanation

The micturition is the process of accumulation of formed urine in the urinary bladder and evacuation of the same 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 eo to compression by the contracting bladder muscles. When enough urine has accumulated in the bladder to distend to bladder and raise its pressure sufficiently, a spontaneous nervous activity (reflex) is initiated, the causes the smooth muscles on the bladder wall contract and the urethral sphincters, which guard the urethra, to relax. urine consequently flows from the blader through the urethra to the exterior.