Anoderm

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The anoderm , also called anal mucosa , Analkanalhaut or anal skin referred to is one with many nerve endings provided mucosa in the lower portion of the anal canal ( canalis analis ). The anoderm is part of the continence organ .

Anatomy and function

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

The anoderm consists mainly of multi-layered uncornified squamous epithelial cells . In the distal (lower) area, where it is exposed to air, there are also keratinized squamous cells. It is free from skin appendages (adnexa) such as hair or glandular tubes. The anoderm is of ectodermal origin and has a length of about 40 mm. The dentate line , the upper boundary line of the anoderm, is the boundary line between the ectoderm and the endoderm . The lower borderline of the anoderm is the linea anocutanea . Behind it begins the perianal skin , which consists of multi-layered keratinized squamous epithelial cells and is more pigmented in most people (see also: Anal bleaching ). The anoderm, which is firmly connected to the sphincter ani internus muscle , is almost white, which is why this area is also called the zona alba .

Through the innervation with sensitive nerve fibers , a healthy person can differentiate between intestinal gases, fluid and solid stool and thus assess the consistency of the faeces.

Diseases

The anoderm is the starting point for a number of proctological diseases. For example, 75% of all anal cancers are squamous cell carcinomas . The pain that an anal fissure creates is caused by the tearing of the anoderm.

Individual evidence

  1. ↑ a b H. Rohde: Lehratlas der Proktologie. Georg Thieme, 2006, ISBN 3-131-40881-2 , p. 66. Restricted preview in the Google book search
  2. ↑ Michael Schünke, Erik Schulte and others: Prometheus - learning atlas of anatomy. Georg Thieme Verlag, 2009, ISBN 3-131-39532-X , p. 232. Restricted preview in the Google book search
  3. ^ JM Mayer: rectum. In: NT Schwarz, KH Reutter: General and visceral surgery. Edition 6, Georg Thieme Verlag, 2009, ISBN 3-131-26346-6 , p. 240. Restricted preview in Google book search
  4. ↑ H.-J. Schmoll, K. Höffken, K. Possinger (Eds.): Compendium of internal oncology. 4th edition. Springer, Berlin 2005. 3 volumes. ISBN 978-3-540-20657-6 , p. 3940. Restricted preview in Google Book Search