Contents 1 Pinyin 2 English Reference 3 Definition 4 About the anal valve 5 About the anal column 6 About the anal canal 7 About the rectum 8 References attached: 1 The tooth line in ancient books 1 Pinyin
chǐ xiàn 2 English reference
dentate line [Traditional Chinese Medicine Terminology Approval Committee. Traditional Chinese Medicine Terminology (2013)] 3 Definition
The dentate line refers to the anal valve and anal column The base of the vagina forms a zigzag-shaped circular line at the junction of the rectum and anal canal [1].
The connection between the vagina and the skin of the anal canal forms an irregular line called the dentate line or dentate line. The tooth line is an important clinical sign and has important clinical significance.
4 About the anal valve
The anal valve (*** valve) refers to the semilunar fold between the bases of two adjacent anal columns [1]. 5 About the anal column
The anal column (*** column) is also called the "rectal column" [1]. Because the lower end of the rectum is connected to the narrowed anal canal, the rectal mucosa forms 6 to 10 raised longitudinal folds [1]. 6 About the anal canal
The anal canal (*** c ***) refers to the end of the digestive tube that connects with the end of the rectum and goes down to the edge of the vagina [1].
The anatomical anal canal (anatomic *** c ***) refers to the part from the dentate line to the anal verge [1].
The surgical anal canal (surgical ***c***) refers to the part from the anal edge to the upper edge plane of the anorectal ring [1].
The anal canal is the end of the digestive tract, about 3cm long. Its outer end is the vaginal edge, and its upper end is connected to the rectum. The tooth line is the junction line between the anal canal and the rectum. The anal canal can be divided into anatomical anal canal and surgical anal canal. Anatomy of the anal canal is the part below the tooth line. The total length of the surgical anal canal is about 5cm, starting from the anal verge and going up to the reduced part below the ampulla of the rectum. The upper 2/5 is the rectal mucosa and the lower 3/5 is the anal canal skin. . 7 About the rectum
The rectum refers to the section of intestine between the end of the sigmoid colon and the tooth line [1]. That is the end of the large intestine[2]. Because of its direct connection to ***, it is named [3].
Volume 1 of "Acupuncture and Moxibustion Juying": "The large intestine is connected to the rectum, and the lower part of the rectum is the vagina."
The rectum is located in the pelvic cavity (Figure 223), with a total length of about 15 to 16 meters Centimeters, it goes from the plane of the third sacral vertebra to the front of the sacrococcygeal bone, passes through the pelvic diaphragm, and finally penetrates. The section below the pelvic diaphragm is also called the anal canal *** c ***, which is about 3 to 4 centimeters long. The muscular membrane of the rectum, like other parts, is composed of two layers of smooth muscle, the outer longitudinal and the inner ring. The circular muscle is particularly thickened at the anal canal, forming the *** internal sphincter. Surrounding the internal sphincter is the external sphincter, which is composed of striated muscle. Contraction of the sphincter prevents the discharge of feces.
Figure 223 Rectum and anal canal
The upper end of the rectum is connected with the sigmoid colon at the level of the 2nd to 3rd sacral vertebrae, descends in front of the sacrococcyx, and ends at the tooth line slightly below the tip of the coccyx. , and connected to the anal canal. The total length of the rectum is 12cm. The upper part of the rectum and the curvature of the sacrum together form the sacral flexure. At the same time, the size of the rectal cavity is the same as that of the sigmoid colon at the upper end, and the lower end expands into the rectal ampulla. The anterior wall of the ampulla bulges forward, forming a perineal flexure at almost a right angle with the anal canal. Therefore, attention should be paid to this anatomical feature during colonoscopy. The front and sides of the upper 1/3 of the intestine are covered by the peritoneum, and the front and middle 1/3 of the intestinal peritoneum are reflected forward to form a rectovesical depression or a rectouterine depression. This depression is the lowest point of the abdominal cavity in the upright position. The lower 1/3 of the rectum is completely outside the abdominal cavity. The muscularis of the rectal wall is the same as that of the colon, with the muscularis of the rectum thickening in its lower part to become the ***internal sphincter. The inner surface of the rectum is a thick layer of mucosa. The rectal mucosa has three semi-moon-shaped transverse folds, also known as the rectum. The superior fold is located 12 cm above the dental line and is the dividing fold between the rectum and the sigmoid colon. The middle fold is located on the right side wall, 8cm above the dental line, equivalent to the peritoneal rectal fold. The inferior fold is located on the left anterior wall, 5 cm above the dental line.