What is Micturition? Explain.
Topic: Micturition
Answer
MICTURITION is the process of EXPELLING URINE from the urinary bladder through the urethra.
When about 300-400 ml of urine collects, the stretching of the bladder wall stimulates receptors that send impulses to the central nervous system, producing the urge to urinate. The urethral sphincters then relax and the bladder muscles contract, forcing the urine out.
The question says "Explain", so a one-line definition is not enough — add the mechanism.
Two points earn the mark: WHAT it is (expelling urine from the bladder) and HOW it is triggered (stretching of the bladder wall sends nerve impulses; the sphincter relaxes and the bladder contracts).
Note that micturition is partly VOLUNTARY in adults — the external sphincter is under conscious control, which is why it can be delayed. In infants it is purely reflex, because that control has not yet developed.