What is dentate line?
The dentate line is located one third below the entire surgical anal canal. The area between the dentate line and the anal verge is called the “anoderm,” which is a nonkeratinized squamous epithelium and has no structures such as hair follicles or glands. It is also soft when palpated and sensitive to pain.
How far up is dentate line?
The median distance between the dentate line and the anal verge was 2.0 cm. The distances of each rectal valve (proximal to distal) to the anal verge and dentate line were 11.4 ± 2.0 cm, 8.6 ± 2.0 cm, 6.0 ± 1.7 cm and 9.1 ± 1.6 cm, 6.3 ± 1.6 cm, 3.7 ± 1.5 cm, respectively.
What is mesorectal fat?
The mesorectal fascia is a layer of connective tissue enclosing the perirectal fat that surrounds the rectum. It is an important anatomical structure in rectal cancer staging, as it forms the circumferential resection margin for the non-peritonealised portion of the rectum.
Why dentate line is called watershed line?
The dentate line is formed by the anal columns, which consists of a series of anal sinuses (which drain anal glands) at approximately the midpoint of the anal canal. Note that the dentate line is a “watershed area” and that the exact transition of epithelium and neurovascular supply is varied.
Are mesorectal lymph nodes normal?
Conclusions: Our study confirmed that more than 30 lymph node units normally exist in the mesorectal area. In view of previous studies demonstrating advantages of increasing the number of lymph nodes evaluated, staging of rectal cancer might be improved by counting more than 12 lymph nodes per specimen.
What are mesorectal lymph nodes?
Mesorectal lymph nodes refers to lymph nodes that are present in the mesorectal fascia. Their assessment is important in the staging of colorectal tumors such as rectal cancer and anal cancer.
What is the white line of Hilton?
The anocutaneous line, also called the Hilton white line or intersphincteric groove, is a boundary in the anal canal. The interior of the anal canal and lower part of the rectum. (Line not shown but region is visible.) Below the anocutaneous line, lymphatic drainage is to the superficial inguinal nodes.
What is the valve of Houston?
The transverse folds of rectum (or Houston’s valves or the valves of Houston) are semi-lunar transverse folds of the rectal wall that protrude into the rectum, not the anal canal as that lies below the rectum.
What is mesorectal lymph node?
Where are the mesorectal lymph nodes?
There are few lymph nodes within the mesentery of the lower third of the rectum and relatively few in the right and left lateral portions of the mesorectum. We confirm that the majority of nodes are located in the proximal two-thirds of the posterior rectal mesentery.
Why is my poop sticking to my bum?
Smelly and sticky stools are typically a symptom of nutrient malabsorption. This means your body isn’t able to completely absorb and digest nutrients from your gastrointestinal tract due to damage to the small intestine, not having enough pancreatic enzymes, liver disease, HIV/AIDs, or other conditions.
Why pectinate line is called watershed line?
The pectinate line is called the watershed line because it separates the two entirely different parts of the anal canal (in terms of development, nerve supply, blood supply and lymphatic drainage).
What does the pectinate line do?
Overview. The pectinate line (anocutaneous line, dentate line, anal verge, anorectal junction) is a line which marks the end of the rectum and the beginning of the anal canal. Developmentally, this line provides the hindgut and proctodeum junction.