Urination, also known as
micturition,
voiding,
peeing,
weeing,
pissing, and more rarely,
emiction, is the ejection of
urine from the
urinary bladder through the
urethra to the outside of the body. In healthy humans the process of urination is under voluntary control. In
infants, elderly individuals and those with neurological injury, urination may occur as an
involuntary reflex. In other
animals, in addition to expelling waste material, urination can
mark territory or express
submissiveness. Physiologically, micturition involves coordination between the
central,
autonomic, and
somatic nervous systems. Brain centers that regulate urination include the
pontine micturition center,
periaqueductal gray, and the
cerebral cortex. In males urine is ejected through the
penis, and in females through the urethral opening.