4.1
15
Structure of the anterior and lateral abdominal wall
The ventrolateral abdominal wall is formed by number of layers which need to be cut when opening the abdominal cavity (laparotomy). Following laparotomy, it is necessary to close them in the proper anatomical position.
• 1 Skin and subcutaneous tissue • 1.1 Fatty layer (panniculus adiposus) – contains subcutaneous veins • 1.2 Fascia of Camper – composed of fine fibrous fibers within subcutaneous fat • 2 Fascia of Scarpa (fascia subcutanea abdominis)
1
1.1
1.2 2
3
4
9
8 7 6 5
– a membranous layer of subcutaneous tissue (stratum membranosum telae subcutaneae) – separates the subcutaneous and deep fatty layer 3 Deep fatty layer – thinner than the superficial fatty layer 4 Superficial abdominal fascia – the fascia of the external oblique 5 External oblique 6 Internal oblique 7 Transversus abdominis 8 Transversalis fascia – part of 1.1 1.2 2 3 4 5 6 7 8 9 the parietal abdominal fascia 1 9 Parietal peritoneum
• • • • • • •
Layers of the abdominal wall Section of the abdominal wall
4.1.1
Rectus sheath – Vagina musculi recti abdominis
The muscular layer of the anterior abdominal wall is represented by the rectus abdominis and its sheath. It is formed by a connection of the aponeurosis of the oblique and transverse muscles (linea alba) and rectus abdominis. The structure of this sheath varies above and below the umbilicus, the border being the arcuate line (of Douglas). Above umbilicus (in ventrodorsal direction)
• • • • • • • •
1 Rectus sheath (vagina musculi recti abdominis) – the anterior layer of rectus sheath 1.1 Aponeurosis of the external oblique 1.2 Aponeurosis of the internal oblique – the anterior part 2 Rectus abdominis and epigastric vessels 3 Rectus sheath (vagina musculi recti abdominis) – the posterior layer of the rectus sheath 3.1 Aponeurosis of the internal oblique 3.2 Aponeurosis of the transversus abdominis 4 Transversalis fascia
Below umbilicus (in ventrodorsal direction)
• 1 Rectus sheath (vagina musculi recti abdominis) • 1.1 Aponeurosis of the external oblique • 1.2 Aponeurosis of the internal oblique • 1.3 Aponeurosis of the transversus abdominis • 2 Rectus abdominis – the caudally short pyramidalis (located ventrally to the rectus abdominis) 3 Transversalis fascia
•
1.1 1.2
1
3.2
3
3.1
2
4
Above the umbilicus 1
2
1.1 1.2 1.3 2
3
Below the umbilicus
555