Micturation

Micturation

The urge to pass urine is felt when the bladder contains about 200-300mls of urine. Stimuli are conveyed to the hypothalamus and corticoid centre of the brain via the sympathetic nerves. The act can be delayed until when suitable, but it become irresistible when the volume get to 700mls. The act of micturation is a reflect response performed by nerve impulse from the cerebral cortex which increase the parasympathetic activity and decreases the sympathetic activity and decreases the sympathetic activity. This causes the internal sphincter to relax by the action of the bells muscle while that of the bladder muscle contract. If the urge is not resisted the external sphincter relaxes and the bladder is emptied. In porous women and pregnancy, however, stress incontinence may be experienced when coughing, laughing, sneezing and other factors that raise intral abdominal pressure. Other psychological stimuli operate such as walking after sleep, arriving or leaving home, others from external stimuli like sound and feeling of water or toilet seat. Regular exercises such as walking, swimming, running, pelvic floor exercise can help to raise the tone of the voluntary muscles. In the newborn the ability to control is underdeveloped until about 2-3 years when the child learns to control the urge to void.