7. Abdominal wall, neurovascular, hernias 2 and incisions .pptx Flashcards
Name the 3 muscles of the posterior abdominal wall
- Quadratus lumborum
- Psoas major, possibly with poses minor overlying it
- Iliacus
(Diaphragm contribute to the upper, posterior abdominal wall)
Function of the posterior abdominal wall muscles
Quadratus lumborum stabilises the 12th rib for diaphragmatic movement in respiration
Psoas major and iliac pass to the lesser trochanter together and are powerful hip flexors
What is the position of the iliolumbar ligament?
From the transverse process of L5 to the posterior superior iliac spine and adjacent iliac crest
Quadratus lumborum:
Attachments?
Nerve supply?
Attachment:
From iliac crest, iliolumbar ligament and L5 LP
To 12th rib and L1-4 TPs
Nerve supply: T12 to L1-4
Psoas major:
Attachment?
Nerve supply?
Attachments:
From transverse processes, bodies, and intervertebral discs of 12th thoracic and five lumbar vertebrae;
To lesser trochanter of femur (with Iliacus)
Nerve supply: L1 to 3
Psoas minor:
Attachments?
Nerve supply?
Attachments:
From T12/L1 vertebral bodies
To pectineal line and iliopectineal eminence on pelvic bone
Nerve supply: L1
(Absent in 50%)
Iliacus:
Attachments?
Nerve supply?
Attachments:
From Iliac fossa
To lesser trochanter of femur (with psoas)
Nerve supply: Femoral nerve L2, 3, 4
What are the contents of the femoral sheath?
Femoral artery
Femoral vein
Femoral canal (lymphatics e.g. Cloquet’s lymph node that receives directly from the glans of penis or clitoris)
Where is the site of a femoral hernia?
Femoral sheath, below and lateral to the pubic tubercle.
This is an extension of the abdominal transversals fascia
What are the boundaries of the femoral canal?
Medial, lateral, posterior, anterior
Medial: Lacunar ligament
Lateral: Femoral vein
Posterior: Ligament for ring
Anterior: Inguinal ligament
Which nerves supply the skin and muscle of the abdominal wall?
Supplied in segments by ventral rami of the spinal nerves T7-12 and L1 (as iliohypogastric and olio-inguinal nerves)
What is the epigastric dermatome? Where does the referred pain go to?
Epigastric: T7
Referred pain: Stomach and oesophagus
Where is the umbilical dermatome? Where is it’s referred pain?
Umbilical: T10
Referred pain: Appendix, gonad, small intestine
What is the suprapubic dermatome? Where is it’s referred pain?
Suprapubic: T12
Referred pain: Lower colon, bladder, uterus
What must be down when splitting rectus abdominis surgically to avoid denervation?
The fibres must be pushed laterally towards the nerves
What is the pathways of the nerves that supply the abdominal muscles?
Anterior rami of T7-12 and L1 pass between internal oblique and transversus abdominis
Enter rectus sheath to supply rectus abdominis, from lateral to medial. T12 only supplies pyramidalis
Terminates by peircing the ant wall of the sheath and supplying the overlying skin.
Iliohypogastric nerve pierces the external oblique aponeurosis above superficial inguinal ring
Ilio-inguinal nerve emerges through superficial ring.
End by supplying the skin above the inguinal ligament
What does the iliohypogastric nerve supply?
Result of injury?
Internal oblique and Transverse abdominis fibres that form the conjoint tendon.
Injury: Weakens the conjoint tendon and pre disposal to hernia
What are the muscular branches of the lumbar plexus and which nerve fibres do they carry?
Iliohypogastric (L1) Ilio-inguinal (L1) Genitofemoral (L1, 2) Lateral Femoral Cutaneous (L2, 3) Obturator (L2, 3, 4) Femoral (L2, 3, 4)
Which muscle is the lumbosacral plexus formed in?
Psoas
What is McBurney’s point?
1/3 of the way up that line from the ASIS to the umbilicus
Note: Point of appendicectomy incisions
Which vessels provide the arterial supply to the abdominal wall?
Lower 2 posterior Intercostal arteries 4 Lumbar arteries Sup, inf and superficial epigastric artery Deep circumflex iliac artery Superficial epigastric Superficial circumflex iliac artery
Superior epigastric artery:
Pathway?
Supplies which muscles?
Is a branch of the internal thoracic (mammary) artery, and enters the upper part of the rectus sheath between the sternal and costal origins of the diaphragm
It descends behind the rectus muscle, SUPPLYING the upper
central part of the anterior
abdominal wall, and anastomoses
with the inferior epigastric artery
Branches from the musculophrenic branch of the internal thoracic artery SUPPLY the upper, lateral abdominal wall
Inferior epigastric artery:
Branch of which vessel?
Pathway?
Supplies?
The inferior epigastric artery is a branch of the external iliac
It runs upward and medially along the medial side of the deep inguinal ring and pierces the transversalis fascia to enter the rectus sheath anterior to the arcuate line.
Supplies:
-Lower central part of the anterior abdominal wall
Anastomoses with sup epigastric artery
Deep circumflex iliac artery:
Branch from which vessel?
Pathway?
Supplies what?
Branch of external iliac just above the inguinal ligament
Pathway: Runs upwards and laterally towards the ASIS, then along iliac crest
Supplies: Lower, lateral part of the abdominal wall
The superficial epigastric and superficial circumflex iliac arteries:
Branch of which vessel?
Supply what?
Branch from femoral just below inguinal ligament
Supply: Lower abdominal wall
Which vessels pass forwards between the muscle layers and supply the lateral abdominal wall?
Lower 2 posterior intercostal arteries
The 4 lumbar arteries
What is the structure of the abdominal wall venous drainage system?
The veins radiate out from the umbilicus to drain into the femoral and external iliac veins inferiorly and the internal thoracic and axillary veins superiorly.
Para-umbilical veins connect the system through the umbilicus to the portal veins of the liver
The superficial epigastric and superficial circumflex iliac veins drain in to the proximal end of the great (long) saphenous vein along with the superficial and deep external pudendal veins; these 4 veins are important in varicose vein surgery
What vessel forms the portosystemic venous anastomosis?
What is the result of obstruction of this vessel?
Para-umbilical veins connect the system through the umbilicus to the portal veins of the liver
If obstructed, resulting in Caput Medusae
What is the superficial lymphatic drainage of the abdominal wall?
Anteriorly:
Above umbilicus –> Axillary nodes (Anterior/pectoral group)
Below umbilicus –> Superficial inguinal nodes
Posteriorly:
Above iliac crest –> Axillary nodes (Posterior/ subscapular group)
Below iliac crest –> Superficial inguinal nodes
What is the lymph drainage pathway after the superficial inguinal nodes?
The superficial nodes drain to the deep inguinal nodes (in the femoral canal), which drain to external iliac and then para-aortic nodes
What is the lymph drainage of the deep abdominal wall?
Inferiorly: To external iliac and then para-aortic nodes
Superiorly: To parasternal nodes alongside the internal thoracic artery and then mediastinal nodes
Which parts of the contractile tissue of GIT ISN’T smooth muscle?
Pharynx
Upper third of oesophagus
External sphincter
