Question

Explain the process of micturition

Answer 1

Answer

• The process of release of urine from bladder is called micturation.
• The neural mechanisms causing micturation is known as the micturation reflex.
• Contraction and relaxation of the bladder are caused by impulses from the sympathetic and parasympathetic nerve fibers.
• The bladder stores urine temporarily till a voluntary signal is given by central nervous system. This signal initiates the streching of the urinary bladder as it gets filled with urine.
• As a response, the strech receptors on the walls of the bladder send signals to the CNS.
• The CNS passes message to initiate the contraction of smooth muscle (detrusor muscle) of the bladder and relaxation of the urethral sphincter surrounding the opening of the bladder which causes release of urine. It allows urine to pass out of the bladder into the urethra.
• The external urethral sphincter is voluntary. Relaxation of external urethral sphincter cause urination.