Pectinate line

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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.)
Latin	linea anocutanea
Dorlands/Elsevier	l_10/12496033

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 represents the hindgut-proctodeum junction.

It is an important anatomical landmark, and several distinctions can be made based upon the location of a structure relative to this line:

Distinction	Above pectinate line	Below pectinate line
destination of lymph drainage	internal iliac lymph nodes,[1] inferior mesenteric lymph nodes[2] (pararectal lymph nodes),	superficial inguinal lymph nodes (below Hilton's white line)[3]
epithelium	columnar epithelium (as is most of the digestive tract - the line represents the end of the part of the body derived from the hindgut)	stratified squamous epithelium (as is most of the skin.)
artery	superior rectal artery	inferior rectal arteries
vein	superior rectal vein	inferior rectal vein
hemorrhoids classification	internal hemorrhoids (not painful)	external hemorrhoids (painful)
nerves	inferior hypogastric plexus	inferior rectal nerves

[edit] Additional images

Microscopic cross section of the recto-anal junction.

Anatomy of the anus and rectum

Coronal section of rectum and anal canal.

[edit] References

[edit] External links

• Pectinate+line at eMedicine Dictionary
• Norman/Georgetown pelvis (rectum)
• GI49 at FPnotebook

v • d • e Anatomy of torso, digestive system: Gastrointestinal tract Upper GI: to stomach Mouth • Pharynx (nasopharynx, oropharynx, hypopharynx) • Esophagus • Crop Upper GI: stomach rugae – gastric pits – cardia/gland – fundus/gland – pylorus/gland – pyloric antrum – pyloric canal – greater curvature – lesser curvature – angular incisure Lower GI: intestines Small intestine: Duodenum (Suspensory muscle, Major duodenal papilla, Minor duodenal papilla) • Duodenojejunal flexure • Jejunum • Ileum • continuous (intestinal villus, crypts of Lieberkühn, circular folds) Junction: Vermiform appendix • Ileocecal valve Large intestine: Cecum • Colon (ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon, sigmoid colon) • continuous (taenia coli, haustra, epiploic appendix) Lower GI: termination Rectum: Houston valve • rectal ampulla • pectinate line Anal canal: anal valves • anal sinuses • anal columns • Hilton's white line Anus: Sphincter ani internus muscle • Sphincter ani externus muscle Lower GI: lymph GALT: Peyer's patches (M cells)