ANATOMY

Detailed explanation-1: -Urethra. This tube allows urine to pass outside the body. The brain signals the bladder muscles to tighten, which squeezes urine out of the bladder. At the same time, the brain signals the sphincter muscles to relax to let urine exit the bladder through the urethra.

Detailed explanation-2: -Bladder emptying is known as urination. Urethra. A tube located at the bottom of the bladder that allows urine to exit the body during urination. All parts of the urinary tract-the kidneys, ureters, bladder, and urethra-must work together to urinate normally.

Detailed explanation-3: -The urine flows from the kidneys through the ureters to the bladder. The urine is stored in the bladder until it leaves the body through the urethra.

Detailed explanation-4: -Controlling the outflow of urine are two valves, or sphincters, located in the bladder neck and earliest portion of the urethra. The bladder neck sphincter is under involuntary (autonomic) control while the urethral sphincter has both voluntary and involuntary components.