SPHINCTER ANI EXTERNUS MUSCLE Meaning and
Definition
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The sphincter ani externus muscle refers to a specific muscle located in the pelvic region responsible for the control and regulation of the anal opening. It serves as an external sphincter that encircles the anus, acting as a barrier that allows voluntary control over the opening and closure of the anal canal.
The sphincter ani externus muscle plays a vital role in maintaining continence and controlling the elimination of waste from the digestive system. During a state of rest, this muscle remains contracted, maintaining closure of the anal canal to prevent the involuntary leakage of fecal matter.
When it is necessary to defecate, the sphincter ani externus muscle can be consciously relaxed, allowing the anal opening to widen and ease the passage of stool. This relaxation is typically initiated through signals from the brain and coordinated by the nervous system.
In addition to its role in voluntary control, the sphincter ani externus muscle also provides support to the surrounding structures within the pelvic floor. It contributes to the maintenance of pelvic organ integrity and overall stability.
Impairment or dysfunction of the sphincter ani externus muscle can lead to various issues related to bowel control, including fecal incontinence. When this muscle is weakened or damaged, individuals may experience difficulties in maintaining voluntary control over bowel movements and have a higher likelihood of unintentional passage of stool.
