The anterior abdominal wall is composed of multiple layers that provide structural integrity and protection for internal organs. Beginning from the surface, these layers are: skin, outer subcutaneous layer of superficial fascia (Camper√ïs fascia), deep membranous layer of superficial fascia (Scarpa√ïs fascia), external oblique, internal oblique, transversus abdominis, transversalis fascia, extraperitoneal fat, and parietal peritoneum. The rectus abdominis, important for the valsalva maneuver, is covered by anterior and posterior rectus sheaths above the arcuate line.
The arcuate line serves as the lower boundary of the posterior rectus sheath and also marks the point where the inferior epigastric vessels pass through the rectus abdominis. These vessels should be tied off during abdominal surgery to prevent hemorrhage. McBurney's point is a clinical landmark where pain manifests in cases of acute appendicitis due to irritation of the parietal peritoneum. The iliohypogastric nerve can be at risk during abdominal surgery, and its injury leads to diminished sensation and burning neuropathic pain in the suprapubic area.
The layers of the anterior abdominal wall include the skin, the outer subcutaneous layer of superficial fascia (Camper√ïs fascia), deep membranous layer of superficial fascia (Scarpa√ïs fascia), the muscles and their fascias (external oblique, internal oblique, rectus abdominis, transversus abdominis, transversalis fascia), as well as the extraperitoneal fat and parietal peritoneum.
The rectus abdominis muscle plays a critical role in the valsalva maneuver, which involves holding one's breath and exerting abdominal pressure. This muscle contracts to increase intra-abdominal pressure, aiding in activities like defecation and lifting.
The arcuate line defines the lower boundary of the posterior rectus sheath and marks the location where the inferior epigastric vessels pass through the rectus abdominis. The umbilicus is located above the arcuate line, and there is no posterior rectus sheath below this line.
McBurney√ïs point is a specific location on the right side of the abdomen where pain is often felt during acute appendicitis. The pain is caused by the inflamed appendix irritating the parietal peritoneum.
Injury to the iliohypogastric nerve during abdominal surgery can lead to diminished sensation and burning neuropathic pain in the suprapubic area. This nerve supplies sensory fibers to the skin over the lower abdomen.