IGNIS | Page 19

Ureters This pair of tubes carry urine from the kidneys to the urinary bladder. They are around 11 inches long and run on the left and right side of your body, parallel to your spine. Urinary Bladder This is another sac-like organ that is hollow in the middle, where it stores urine. As the hollow space fills, the elastic walls of the bladder are stretched to accommodate anything from 600-800ml of urine. Urethra The tube through which your urine passes out of your body from the bladder is called the urethra. This is different in males and females. In females, it is only around 2 inches long, and it ends just above the vaginal opening. In males, the urethra is around 9 inches long, and ends at the tip of their penis. In the case of males, the urethra is also part of the reproductive system as it also carries sperm out of the body. There are two sphincter muscles that control the flow of urine through the urethra. The internal sphincter is made of smooth muscle and opens involuntarily whenever the bladder reaches a certain level – this is what tells us we need to urinate. The external sphincter is made of skeletal muscle and we can open it to allow urine out or hold it closed to delay urination. IGNIS 19