Explanation:
The Urinary System:
The organs, tubes and muscles that produce, store and excrete urine are part of the urinary system. It consists of:
Two kidneys (produce urine by filtering blood)Two ureters (carry urine from kidneys to bladder)Bladder (stores urine until excreted)Two sphincter muscles (control the flow of urine from the bladder)Urethra (allows excretion of urine from bladder)The process of urination relies majorly on the control of sphincter muscles of the bladder by the modulatory centers in the central and peripheral nervous system. The two sphincter muscles work in an antagonistic manner. When the bladder is being filled, the detrusor muscle, a complex of smooth muscles, relaxes to accommodate the urine. Whereas, the sphincter muscle, located at the base of the bladder,contracts to prevent leakage of the urine.
During urination, the detrusor muscle contracts to expel the urine while the sphincter muscle relaxes to enable the excretion of urine through the urethra