Rectus sheath

Rectus sheath above the arcuate line

The rectus sheath ( lat. Vagina musculi recti abdominis ) is the covering formed by the tendon plates of the muscles of the anterior abdominal wall around the rectus abdominis muscle . A distinction is made between the anterior wall ( lamina anterior ) and the posterior wall ( lamina posterior ) of the rectus sheath, whereby the lamina posterior only exists from the breastbone ( sternum ) to a few centimeters below the navel, while the anterior lamina extends to the pubic bone . The point from which the posterior wall is formed only from the transversalis fascia and peritoneum is called the arcuate line; from this point onwards the anterior wall is formed by all three aponeuroses. The arcuate line is about 3 to 5 cm below the navel .

The following muscle aponeuroses above the arcuate line are involved in the formation of the two sheets of the rectus sheath (from outside to inside):

• outer sheet:
  • Musculus obliquus externus abdominis : Involved in the anterior wall, but also releasesfibers into the contralateral posterior wallafter crossing the linea alba
  • Musculus obliquus internus abdominis : forms part of both the anterior wall ( lamina anterior ) and the posterior wall ( lamina posterior ), in which the aponeurosis lateral to the rectus abdominis muscle splits into an anterior and posterior part
• inner sheet:
  • Musculus transversus abdominis : involved in the posterior wall, but releases fibers into the anterior wall analogous to the M. obliquus externus abdominis
  • Transversalis fascia
  • Parietal peritoneum

Below the arcuate line , the rectus sheath is formed as follows (from outside to inside):

• outer sheet:
  • External obliquus abdominis muscle
  • Internus abdominis oblique muscle
  • Transversus abdominis muscle
• inner sheet:
  • Transversalis fascia
  • Parietal peritoneum

literature

• Gerhard Aumüller et al .: Anatomy (= dual series ). Thieme, Stuttgart 2006, ISBN 3-13-136041-0 .
• Michael Schünke: Prometheus. Anatomy Learning Atlas . Volume 1. 2., revised. u. exp. Ed. Thieme, Stuttgart 2007, ISBN 978-3-13-139522-1 .