The following are impoant in maintenance of normal fecal continence except –
**Core Concept**
Normal fecal continence is maintained by a complex interaction of the anal sphincter muscles, the rectal wall, and the nervous system. The anal sphincter muscles consist of the internal anal sphincter (IAS) and the external anal sphincter (EAS), which work together to regulate the passage of stool.
**Why the Correct Answer is Right**
The internal anal sphincter (IAS) is a smooth muscle layer that is always contracted, providing a constant tone to the anal canal. This helps to prevent the involuntary passage of stool. The external anal sphincter (EAS) is a skeletal muscle that is under voluntary control, allowing for the conscious contraction and relaxation of the anal canal. The puborectalis muscle, a part of the levator ani muscle group, plays a crucial role in maintaining the anorectal angle, which is essential for fecal continence.
**Why Each Wrong Option is Incorrect**
**Option A:** The anal verge is the distal end of the anal canal, but it is not directly involved in the maintenance of fecal continence. Instead, it is the site where the anal canal transitions to the perianal skin.
**Option B:** The rectal ampulla is the dilated portion of the rectum that stores stool, but it is not directly involved in the maintenance of fecal continence.
**Option C:** The anal glands are small, mucous-secreting glands located in the submucosa of the anal canal, and while they play a role in the lubrication of the anal canal, they are not directly involved in the maintenance of fecal continence.
**Clinical Pearl / High-Yield Fact**
The anorectal angle, which is maintained by the puborectalis muscle, is critical for fecal continence. A decrease in this angle can lead to fecal incontinence.
**Correct Answer: C. The anal glands.**