what is a sphincter?

Question

i know theres anus, rectum, bumhole and all that

Answer 1

A sphincter is a circular muscle which normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning. There are at least 42 different sphincters in the human body, some of them microscopic in size!

This are some examples:
The sphincter pupillae, or pupillary sphincter, belonging to the iris in the eye.
The orbicularis oris muscle, a muscle around the mouth.
The cardia/lower esophageal sphincter, or cardiac sphincter at the upper portion of the stomach. This sphincter prevents the acidic contents of the stomach from moving upward into the esophagus.
The pyloric sphincter, at the lower end of the stomach.
The sphincter of Oddi, or Glisson's sphincter, controlling secretions from the liver, pancreas and gall bladder into the duodenum.
The sphincter urethrae, or urethral sphincter, controlling the exit of urine from the body.
At the anus, there are two sphincters which control the exit of feces from the body (see internal anal sphincter and external anal sphincter). The inner sphincter is involuntary and the outer voluntary.
Sphincters prove effective in the mediation of the entrance or release of liquids and fluids; this is evident in the blowholes of numerous marine mammals, for example.

Answer 2

ah yes, but there are more. A sphincter is any circular muscle in the human body.
When food leaves your stomach, it passes a sphincter into the intestine. You have another at the base of your bladder, I believe.

After those, you'll have to ask Dr. Nick on the Simpsons. He's not a real doctor, but plays one on TV.

Answer 3

My wife and I have been having anal sex off and on for over year. Yes, she has said that the color, of bowels change, and she has complained of the runs. However, different simptoms each time. Also, all these people talking about losing the strength of the anus over time because of anal sex. I gues none of you have a bowel movement. Your anus is streched during a bowel movement, and over the life of any person it will be streched with or without you approvel. Anal sex if fine in moderation. I would not advise it everyday, but I would say it can be an something implemented in the bed room just for something else to do.

Answer 4

The muscle in the anus I believe. It's the one that pinches off terds :-)

Answer 5

Number one is right. Those are the muscles you clench to pinch a terd off.

Answer 6

Is "pinching off turds" a medical term?

Answer 7

u answered your own question