Pectinate line
| Pectinate line | |
|---|---|
 Pectinate line labeled at bottom center. | |
 The interior of the anal cami and lower part of the rectum, showing the columns of Morgagni and the anal valves between their lower ends. (Pectinate line visible but not labeled.) | |
| Details | |
| Identifiers | |
| Latin | linea pectinata, linea anocutanea |
| TA98 | A05.7.05.009 |
| TA2 | 3015 |
| FMA | 29321 |
| Anatomical terminology | |
Thepectinate line(dentate line) is a line which divides the upper two-thirds and lower third of theanal canal.Developmentally, this line represents thehindgut-proctodeumjunction.
It is an important anatomical landmark in humans, and several distinctions can be made based upon the location of a structure relative to this line:
| Distinction | Above pectinate line | Below pectinate line |
|---|---|---|
| Lymphdrainage | internal iliac[1] | superficial inguinal lymph nodes(belowHilton's white line) |
| Epithelium | columnar epithelium(as is most of the digestive tract - the line represents the end of the part of the body derived from thehindgut) | stratified squamous epithelium,non-keratinized (untilHilton's white line,where theanal vergebecomes continuous with the perianal skin containing keratinized epithelium.) |
| Embryological origin[2] | endoderm | ectoderm |
| Artery | superior rectal artery | middleandinferiorrectal arteries |
| Vein | superior rectal veindraining into theinferior mesenteric veinand subsequently thehepatic portal system | middleandinferiorrectal veins |
| Hemorrhoidsclassification | internal hemorrhoids (not painful) | external hemorrhoids (painful) |
| Nerves | inferior hypogastric plexus | pudendal nerves |
Additional images
[edit]-
Microscopic cross section of the anorectal junction. -
Anatomy of the anus and rectum -
Coronal section of rectum and anal canal.
References
[edit]- ^MD, Tao Le, MD, MHS, Vikas Bhushan, MD, Matthew Sochat, MD (2017).First aid for the USMLE step 1 2017: a student-to-student guide.ISBN978-0071831420.
{{cite book}}:CS1 maint: multiple names: authors list (link) - ^Schoenwolf, Gary C.; Bleyl, Steven B.; Brauer, Philip R.; Francis-West, Philippa H. (2014-12-01).Larsen's Human Embryology.Elsevier Health Sciences. p. 372.ISBN9781455727919.
