L3 Anterior Abdominal Wall Flashcards
What are the layers of the abdominal wall from the skin to the intestines?
Skin -> Subcutaneous fat -> External oblique muscle -> Internal oblique muscle -> Transverse muscle -> Parietal peritoneum -> Visceral peritoneum -> Intestines
What are the three paired muscles of the anterolateral abdominal wall? In which direction do these muscles run?
- External oblique runs in inferomedial direction
- Internal oblique runs in a superior medial direction.
- Transverse abdomenis runs in a transverse direction.
What muscles support the anterolateral abdominal wall, anteriorly and posteriorly?
- Rectus abdominis
2. Quadratus lumborum
How is a collateral blood supply achieved in the abdominal cavity?
At the 6 or 7th costal cartilage the internal thoracic bifurcates: one branches moves out laterally as the musculophrenic artery and another projecting inferiorly known as the superior epigastric. The superior epigastric anastomoses with the inferior epigastric artery (this originates from the external iliac - at L4-L5 the aorta bifurcates into the common iliac and the common iliac bifurcates into an external and internal iliac artery).
We can therefore have a collateral blood supply as blood travels down the superior epigastric, down the internal epigastric and into the external iliac. The external iliac goes to the lower limb and becomes the femoral artery, which gives rise to the superficial epigastric, leading blood to the lower limb. The femoral artery also gives rise to the deep circumflex arteries.
What are the thoracoabdominal nerves? What do they supply?
The intercostal nerves continue into the abdomen. In the abdomen there are known as thoracoabdominal nerves. T10 comes from the 10th thoracic vertebrae and comes down to supply around the umbilicus. The thoracoabdominal nerves supply the muscles, the skin and parietal peritoneum. They are somatic nerves supplying the parietal peritoneum. There are five pairs of thoracoabdominal nerves continue from the 7th through 11th intercostal nerves.
What is the rectus sheath?
A sheath made by the aponeuroses and the peritoneum covering the rectus abdomenis muscles.
How is the rectus sheath organised above the umbilicus?
Above the umbilicus the external oblique aponeurosis is anterior to the rectus abdomenis (RA). Half of the internal oblique aponeurosis is anterior to the RA whereas half is posterior to the RA. The aponeurosis of the transverse abdomenis is found posterior to the RA. The peritoneum is also found posterior to the RA.
The transverse fasciae is found behind the transverse abdomenis aponeurosis, posterior to the RA.
How is there rectus sheath organised below the umbilicus?
The aponeuroses of all three layers is found anterior to the rectus abdomenis (RA). The transverse fascia and the peritoneum is found posterior to the RA.
What is the arcuate line?
Below the level of the umbilicus you can start to see the muscle belly. All the aponeuroses are anterior to the rectus abdominis.
The arcuate line signifies the change in the formation of the rectus sheath.
What is the lateral umbilical ligament?
The lateral umbilical fold overlies the inferior epigastric artery (a branch of the external iliac artery) and its accompanying veins. Unlike the median and medial umbilical folds, the contents of the lateral umbilical fold remain functional after birth. The lateral umbilical folds are bilateral raised ridges of parietal peritoneum in the deep aspect of the anterior abdominal wall overlying the inferior epigastric vessels. The paired folds originate medial to the deep inguinal ring and end at the arcuate line on the posterior aspect of the anterior abdominal wall.
What is the medial umbilical ligament?
The medial umbilical ligament (or cord of umbilical artery, or obliterated umbilical artery) is a paired structure found in human anatomy. It is on the deep surface of the anterior abdominal wall, and is covered by the medial umbilical folds (plicae umbilicales mediales).
What is the median umbilical ligament?
The median umbilical fold runs superiorly from the apex of the bladder to the umbilicus. This fold is formed by the underlying median umbilical ligament. It is a remnant of the fetal urachus. The paired medial umbilical folds pass from the pelvis to the umbilicus and cover the underlying medial umbilical ligaments.
Where are hernias most likely to occur?
The inguinal triangle. The inguinal triangle represents and area of weakness in the abdominal wall, through which herniation can occur. Inguinal hernias occur when fatty tissue or a part of your bowel pokes through into your groin at the top of your inner thigh. The inguinal triangle (Hesselbach’s triangle) is a region of the deep part of anterior abdominal wall and defined by the following structures: Medial border: Lateral margin of the rectus sheath, also called linea semilunaris. Superolateral border: Inferior epigastric vessels. The inferior border is formed by the inguinal ligament.
What is the lnguinal canal?
In the inguinal region there is a canal that communicates form the abdominal cavity to the external environment. This is known as the inguinal canal. There is a deep opening known as a deep inguinal ring. Where it opens to the external environment is the superficial inguinal ring. The region connecting them is the inguinal canal. The inguinal canal is a short passage that extends inferiorly and medially through the inferior part of the abdominal wall. It is superior and parallel to the inguinal ligament. The canal serves as a pathway by which structures can pass from the abdominal wall to the external genitalia.
What forms the anterior wall bindery of the inguinal canal?
The anterior wall I formed by the internal oblique and external oblique at the level of the deep ring. At the level of the middle of the canal and superficial ring, it is formed by the external oblique aponeuroses.
Help: https://www.youtube.com/watch?v=9j-Mg86KXkk
