Abdomen Flashcards
What is the anterior abdominal wall?
It is the muscle coating over the abdomen.
What is the function of the anterior abdominal wall?
To allow for lateral rotation, flexion, and extension
What is the gross anatomy / boundaries of the anterior abdominal wall?
Campers fascia / scarpers fascia
External oblique (free edge makes the inguinal ligament)
Internal oblique
Transversus abdominis (internal oblique and transversus abdominis make the conjoint tendon)
Rectus abdominis and the rectus sheath (fibres of external oblique, internal oblique and transversus abdominis change relative to the umbilicus to make the conjoint tendon)
Rests on transversalis fascia and peritoneum
Has umbilical folds on the surface - median, lateral and medial umbilical folds
What are the relations of the anterior abdominal wall?
Median umbilical ligament - obliterated urachus
Lateral umbilical ligament - inferior epigastric artery and vein
Medial umbilical ligament - obliterated umbilical artery
What is the arterial supply of the abdominal wall?
Superior epigastric artery (comes off the internal thoracic artery) + musculophrenic artery
Inferior epigastric artery (comes off the external iliac artery) + deep circumflex iliac artery
Thoracoabdominal artery (continuation of intercostals / lumbar artery)
What is the venous drainage of the anterior abdominal wall?
Superior epigastric vein
Inferior epigastric vein
Thoracoabdominal vein
What is the lymphatic drainage of the abdominal wall?
Superiorly - to the axilla
Inferiorly - to the inguinal nodes
What is the nerve supply of the anterior abdominal wall?
T7 - T12 does the entire anterior abdominal wall (and L1)
**Note - the conjoint tendon is L1, therefore anything which forms the conjoint tendon i.e. transversus abdominis and internal oblique will also be L1
What is the muscles / ligaments and fascia involved with the anterior abdominal wall?
transversalis fascia
peritoneum posteriorly
Median, medial and lateral umbilical ligaments
Conjoint tendon (made by fibres of TA + IO)
inguinal ligament (made of free edge of external oblique)
What are the anatomical variations of the anterior abdominal wall?
Pyramidalis (muscle that may or may not be present)
Persistent vitello intestine duct
Urachus (partial or completely patent)
Congenital herniation - exomphalos, oomphocele
Persistent vitellointestinal duct
How do the fibres of external oblique, internal oblique, transversus abdominis vary with respect to the rectus sheath?
Above arcuate line - EO, IO completely wrap around rectus abdominis, TA and TF only posterior
Below arcuate line - EO, IO, TA all anterior, TF posterior
Just above pubis - EO, IO, TA infront of rectus abdominis, TF posterior
What is the rectus abdominis?
It is one of the main anterior abdominal wall muscles.
It is covered by an aponeuroses which is formed by the anterolateral abdominal wall muscles called the rectus sheath.
It contains tendinous intersections.
What is the function of the rectus abdominis?
It is involved in the flexion of trunk.
What is the anatomy of the rectus sheath?
It is formed by the aponeuroses of the anterior abdominal wall muscles, which cover the rectus abdominis above the arcuate line (not the umbilicus).
Below the arcuate line, the three anterolateral muscles will pass anterior to rectus abdominis.
What is the origin and insertion of the rectus abdominis muscle?
Origin: pubic symphysis and pubic crest
Insertion: Xiphoid process, medial costal cartilage
Contains tendinous intersections
What is the contents of the rectus sheath?
External oblique aponeurosis
Internal oblique aponeurosis
Transversus abdominis aponeurosis
Transversalis fascia
Rectus abdominis muscle
What is the course of the rectus sheath relative to the arcuate line?
The rectus sheath:
Above the arcuate line:
EO aponeuroses is anterior
IO aponeuroses is anterior and posterior
Transversus aponeuroses is posterior
Then transversalis fascia
Below the arcuate line:
EO, IO, TA is anterior
Whereas transversalis fascia is posterior
What are the relations to the rectus abdominis muscle?
Midline - linea alba
Laterally - semilunaris
Posteriorly - transversalis fascia
Superior and inferior epigastric arteries run in the rectus sheath- posterior to rectus abdominis
What is the arterial supply of the rectus abdominis muscle?
Superior epigastric artery
Inferior epigastric artery
They anastomose in the rectus sheath to form the external iliac - subclavian anastomosis.
What is the venous drainage of the rectus abdominis muscle?
The superior epigastric vein and inferior epigastric vein
What is the lymphatic drainage of the rectus sheath?
Superiorly drains to the axilla
Inferiorly drains to the inguinal nodes
What is the nerve supply of the rectus abdominis?
Nerve supply is T7-T12
And then additionally L1 due to the conjoint tendon
What are the muscles / ligaments involved with the rectus abdominis?
Linea alba
Arcuate line
Linea semilunaris
What are the anatomical variations associated with the rectus abdominis muscle?
Pyramidalis