Answer:
1. Urine is formed during process of glomerular filtration in the renal pyramids of the kidneys.
2. This urine is flows through the ureters which connect the kidneys to the bladder.
3. From the bladder, the urethra carries urine to the outside.
4. An internal sphincter and an external sphincter keep the urine in the bladder till it is ready to be excreted.
5. For urination, the bladder walls contract and the urethra and sphincter muscles relax, to allow urine to flow out from the urethra.