The rectus sheath, also called the rectus fascia,
[.] is formed by the
aponeuroses of the
transverse abdominal
The transverse abdominal muscle (TVA), also known as the transverse abdominis, transversalis muscle and transversus abdominis muscle, is a muscle layer of the anterior and lateral (front and side) abdominal wall which is deep to (layered below) th ...
and the
internal and
external oblique muscles. It contains the
rectus abdominis and
pyramidalis muscles.
Structure
The rectus sheath can be divided into anterior and posterior laminae. The arrangement of the layers has important variations at different locations in the body.
Below the costal margin
For context, above the sheath are the following two layers:
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Camper's fascia (anterior part of Superficial fascia)
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Scarpa's fascia (posterior part of the Superficial fascia)
Within the sheath, the layers vary:
Below the sheath are the following three layers:
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transversalis fascia
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extraperitoneal fat
Between the inner surface of the general layer of the fascia which lines the interior of the abdominal and pelvic cavities, and the peritoneum
The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amnio ...
#
parietal peritoneum
The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesothel ...
The rectus, in the situation where its sheath is deficient below, is separated from the
peritoneum
The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mes ...
only by the
transversalis fascia, in contrast to the upper layers, where part of the internal oblique also runs beneath the rectus. Because of the thinner layers below, this region is more susceptible to
herniation.
Above the costal margin
Since the tendons of the internal oblique and transversus abdominis only reach as high as the
costal margin, it follows that above this level the sheath of the rectus is deficient behind, the muscle resting directly on the cartilages of the ribs, and being covered only by the tendons of the external obliques.
Clinical significance
The rectus sheath is a useful attachment for
surgical meshes during
abdominal surgery
The term abdominal surgery broadly covers surgical procedures that involve opening the abdomen ( laparotomy). Surgery of each abdominal organ is dealt with separately in connection with the description of that organ (see stomach, kidney, liver, ...
.
This has a higher risk of
infection
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable di ...
than many other attachment sites.
Additional images
File:Gray396.png, The Cremaster
File:Gray398.png, The interfoveolar ligament, seen from in front.
References
External links
* - "Incisions and the contents of the rectus sheath."
* - "Anterior Abdominal Wall: The Rectus Abdominis Muscle"
* - anterior layer
* - posterior layer above arcuate line
* - posterior layer above arcuate line
*
* - "The Rectus Sheath, Anterior View & Transverse Section"
{{Authority control
Abdomen
Muscles of the torso