If there's no peristalsis, then the urine must be pulled by gravity to get out of our body, I think. Is it true?
2007-02-27 20:41:54 · 5 answers · asked by Lai Yu Zeng 4 in Science & Mathematics ➔ Biology
Urine is excreted because of the pressure in the bladder and not because of peristalsis such as in the bowel. Haven't you ever had to urinate REALLY BADLY?... that is PRESSURE you are feeling. In fact, the urethra is filled with pressoreceptors to control various functions and give feedback to the brain.
2007-02-27 20:52:11 · answer #1 · answered by Anonymous · 0⤊ 1⤋
Ureters, which carry urine from the kidneys to the bladder use peristalsis. Once in the bladder, the urine stretches the walls of the bladder. When you excrete the urine you are using the muscles in the wall of the bladder.
2007-02-27 22:48:39 · answer #2 · answered by peanut509 3 · 1⤊ 0⤋
The bladder is a muscle, plus there are contractions of the muscles around the pelvis which assist. It has nothing to do with paristalsis. The muscles in the urethra block the flow, not initiate it.
The astronauts would urinate in space the same way you would hanging from a tree ... very carefully!
2007-02-27 20:56:06 · answer #3 · answered by Anonymous · 0⤊ 0⤋
peristalsis is only in the ureter, until ur urine reaches your bladder. the ureter transport pee from ur kidneys to be stored in the bladder. after tat, when u pee, u relax a sphincter at the end of ur urethra (which is just a tube connecting ur bladder with the outside world), and squeeze ur bladder. tats how pee comes out. its ur bladder that does the peeing. so u can point upwards and pee still comes out. gravity is totally irrelevant
2007-02-27 20:51:33 · answer #4 · answered by Anonymous · 0⤊ 2⤋
it is the urinary bladder squeezes the urine so that it can be excreted by the body.
2007-02-27 20:52:25 · answer #5 · answered by lagtokz 2 · 0⤊ 1⤋