Bladder is where urine is stored
before its released from the body. Urine enters the bladder from the kidneys, through the ureters. A bladder in an adult
can hold over 2 cups before it needs to be emptied. There are two types of nerves
that are active in the functioning of the bladder. Sensory nerves sense the fullness of the bladder. Motor nerves trigger
the muscles of the external sphincter. The external sphincter is a muscle band at the exit of the bladder
It is controlled voluntarily
to allow you to control when you want to urinate.
There are also muscles in the
walls of the bladder that contract forcing urine out of the bladder. Urine exits the bladder through the urethra.
The urethra is the final stage
of the urinary tract. It excretes urine out of the body, from the bladder. It also has a urinary sphincter, which is the second
stage of the urethra. In males the urethra is longer than in females.
males have three sections of
the urethra, while females only have one part, which leads right out of the body
The first part is called the
prostatic urethra, and it runs from the bladder to the part of the urethra where the vas deferens joins. The second part is
the membranous urethra, and it’s the part that runs through the urinary sphincter. The third part is the spongy urethra
which runs through the length of the penis, and it is stretchy, to allow for erections used in reproduction.