Search results
Results from the WOW.Com Content Network
In humans, the anus (pl.: anuses or ani; from Latin ānus, "ring", "circle") [1] [2] is the external opening of the rectum located inside the intergluteal cleft.Two sphincters control the exit of feces from the body during an act of defecation, which is the primary function of the anus.
The rectum is a continuation of the sigmoid colon, and connects to the anus. The rectum follows the shape of the sacrum and ends in an expanded section called an ampulla where feces is stored before its release via the anal canal. An ampulla (from Latin bottle) is a cavity, or the dilated end of a duct, shaped like a Roman ampulla. [5]
The anal canal is the part that connects the rectum to the anus, located below the level of the pelvic diaphragm. [1] It is located within the anal triangle of the perineum, between the right and left ischioanal fossa. As the final functional segment of the bowel, it functions to regulate release of excrement by two muscular sphincter complexes ...
The internal anal sphincter, IAS, or sphincter ani internus is a ring of smooth muscle that surrounds about 2.5–4.0 cm of the anal canal.It is about 5 mm thick, and is formed by an aggregation of the smooth (involuntary) circular muscle fibers of the rectum.
A third, the largest and most constant, projects backward from the forepart of the rectum, opposite the fundus of the urinary bladder. When a fourth is present, it is situated nearly 2.5 cm above the anus on the left and posterior wall of the tube.
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus.The GI tract contains all the major organs of the digestive system, in humans and other animals, including the esophagus, stomach, and intestines.
It is an important anatomical landmark in humans, and forms the boundary between the anal canal and the rectum according to the anatomic definition. [1] Colorectal surgeons instead define the anal canal as the zone from the anal verge to the anorectal ring (palpable structure formed by the external anal sphincter and the puborectalis muscle). [1]
The intestine is also called the bowel or the gut. The lower GI starts at the pyloric sphincter of the stomach and finishes at the anus. The small intestine is subdivided into the duodenum, the jejunum and the ileum. The cecum marks the division between the small and large intestine. The large intestine includes the rectum and anal canal. [2]