Dentate line

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The Linea dentata ( Latin: linea = 'line', 'line'; dentatus = 'toothed', 'jagged'), also known as the Linea pectinata or crypt line , is an anatomical boundary line in the anal canal .

Schematic representation of the continence organ of a healthy person with an open sphincter muscle. The dentate line is located in the anal canal.

description

At the dentate line , the squamous epithelium of the anal canal meets the oral epithelium of the rectum . The border between the two types of tissue is not straight, but winding and has small, jagged protrusions in the area of ​​the longitudinal folds - the anal papillae . This jagged, 'interlocked' appearance has given the dentate line its name.

The tissue above (proximal) the dentate line (in the oral direction) is formed by the endoderm during embryogenesis , while the tissue below (distal) is of ectodermal origin.

While the tissues located proximal to the dentate line divert the blood supplied via the superior rectal artery and the media rectal artery via the portal vein system (from the superior rectal vein to the portal vein ), this happens in the distal tissue via the media rectal artery and artery inferior rectal is supplied, via the systemic circulation (of the vena inferior rectal to the inferior vena cava ). Correspondingly, malignant tumors of the rectum or anal canal that are above the dentate line metastasize preferentially to the liver and the tumors located below the dentate line to the lungs .

Also for the lymphatic system which is dentate line , a boundary line. Above the dentate line which occurs lymph flow via perirectal (next to the rectum lying), pelvic (in the basin located) and paravertebral (next to the vertebrae located) lymph vessels and below the dentate line via inguinal (in the region of the strips) and femoral (in the range of Thigh) lymphatic vessels.

The above the dentate line located rectal mucosa is largely insensitive to pain. In contrast, the distal squamous epithelium of the anal skin is highly sensitive. This makes it possible, for example, to differentiate between intestinal gases and solid or thin stool .

In the English-language literature which is dentate as pectinate line called.

further reading

  • M. Schünke, E. Schulte and others: Prometheus learning atlas of anatomy. Georg Thieme Verlag, 2009, ISBN 3-131-39532-X , pp. 231-233. limited preview in Google Book search
  • A. Winkelmann, J. Kirsch and others: Pocket textbook anatomy. Georg Thieme Verlag, 2010, ISBN 3-131-62511-2 , p. 384.

Individual evidence

  1. ↑ HP Dienes, J. Klempnauer et al: Analkarzinom. In: G. Adler, C. Beglinger et al. (Ed.): Clinical gastroenterology and metabolism. Springer, ISBN 3-540-65059-8 , p. 700. limited preview in Google book search
  2. ↑ a b M. W. Trammer: Analkanalkarzinome. (PDF file; 209 kB) Dissertation, University of Bonn, 2007, pp. 7–8.
  3. ↑ H. Rohde: Teaching Atlas of proctology. Georg Thieme, 2006, ISBN 3-131-40881-2 , p. 4. Restricted preview in the Google book search