Anterior Abdominal Wall

Question 1

-Quadrants-

Name the quadrants of the Anterior Abdominal wall.

Answer 1

• Left and Right hypochondrium
• Epigastric
• Right and Left lumbar
• Umbilical
• Right and Left inguinal
• Suprapubic (Hypogastric)

Question 2

-Layers in the wall -

• What layers are present in the wall?
• Fascia layers above and below umbilicus?

Answer 2

• Skin
• Superficial fascia
• Muscle and feep fascia
• Extra-peritoneal fascia
• Parietal peritoneum
• Above the superficial fascia is similar to elsewhere
• Below it is divided into camper’s (fatty) and scarpa’s (fibrous) fascia’s

Question 3

-Anterolateral Wall-

Describe the Anterolateral Wall

Answer 3

• Each muscle becomes tendinous across the midline to form a structure which the muscles can attach to. Called the Linea Alba.
• Linea semilunaris down the midline of either side.

Question 4

-External Oblique-

• Direction of fibres
• Aponeurosis
• Action
• Innervation

Answer 4

• Infero-medial from ribs 5-12 to iliac crest and linea alba
• Large trunk connecting muscles on either side. Linea alba from xiphoid to pubic symphysis. The lower border forms the inguinal ligament.
• Flexes trunk using both, and turns to the side using one.
• Anterior rami T7-T12

Question 5

-Internal Oblique-

• Compared to external
• Aponeurosis
• Action
• Innervation

Answer 5

• Deep to external, thinner and smaller
• Ending in linea alba, pectineal lina and pubic crest
• Both sides flex trunk, and one side bends trunk
• Anterior rami T7-12 and L1

Question 6

-Transversus Abdominis -

• Location in relation to internal oblique
• Action of fibres
• Borders
• Innervation

Answer 6

• Deep to internal oblique
• The fibres transverse the abdomen and act to support the wall
• Borders are thoracocolumbar fascia, iliac crest, ilioinguinal ligament, costal cartilages 7-12 to linea alba, pubic crest and pectineal line.
• Anterior rami of T7-L1

Question 7

-Rectus Abdominis-

• Borders
• Action
• Innervation

Answer 7

• From pubic tubercle, crest and symphysis to xiphoid process and costal cartilages of ribs 5-7
• Flexion of trunk with support and compression of abdominal wall
• Anterior rami T7-T12

Question 8

-Pyramidalis-

• Shape and location
• Attachments
• Action

Answer 8

• Small and triangular. Anterior to rectus abdominis.
• Linea alba and pubis.
• Tenses linea alba.

Question 9

-Rectus Sheath-

• What is it formed by?
• Contains?
• 2 parts
• Aponeuroses in lower third

Answer 9

• Transversus abdominis and the external/internal obliques
• Rectus abdominis and pyrimidalis muscles
• Anterior and posterior laminae
• All lie above the rectus abdominis. This means that the rectus lies directly on transversalis fascia. Transition is marked by an arch of fascia in the arcuate line.

Question 10

-Peritoneum-

• Deep to the transversalis fascia is?
• Contents (fat)
• Viscera in extraperitoneal fascia are called?
• Final wall layer is called?
• Peritoneum over viscera called?

Answer 10

• A layer of extraperitoneal fascia
• Contains fat, especially around the kidneys
• Retroperitoneal
• Parietal peritoneum
• Visceral peritoneum

Question 11

-Other features -

• 3 folds on…?
• Median umbilical ligament
• Medial umbilical ligament
• Lateral umbilical fold

Answer 11

• Posterior surface of the anterior abdominal wall
• Urachus remnant
• Umbilical artery remnant
• Contains inferior epigastric vessels

Question 12

Lymphatic Drainage

• Deep drainage

Answer 12

• Via internal thoracic artery to para-sternal nodes. Via abdominal aorta to lumbar nodes and via external iliac artery to external iliac nodes.

Question 13

Nerve Supply

• Skin and muscle and parietal peritoneum
• Intercostal
• Lateral and cutaneous anterior branches

Answer 13

• From T7-T11 (intercostal), T12 (subcostal) and L1 (ilio-hypogastric and ilio-inguinal). All anterior rami.
• Between internal oblique and transversus abdominis. Enters rectus sheath.
• Supply skin.