The process of expelling urine out of the body is called . . . . . . .

In infants,the process of defecation occurs by

The outline of the principal events of urination is given below in an unordered manner:
$I.$ Stretch receptors on the wall of the urinary bladder send signals to the $CNS$.
$II.$ The bladder fills with urine and becomes distended.
$III.$ Micturition.
$IV.$ $CNS$ passes on motor messages to initiate the contraction of the smooth muscles of the bladder and simultaneous relaxation of the urethral sphincter.
The correct order of steps for urination is:

In mammals,the urinary bladder opens into the ........

In micturition:

Micturition reflex is a neural mechanism to