Diaphragm and Posterior Abdominal Wall

  1. Discuss the embryology of the diaphram
    • Formed from septum transversum
    • myotomes C3-C5
    • contributions from body wall and dorsal mesentery
  2. Describe attachments of the diaphram
    • Peripheral: Xiphoid process, lower 6 ribs, arcuate ligaments, and crurae
    • Central: fibrous tissue surrounding the heart
  3. Describe the shape of the diaphram
    • Two domes
    • Ascend as high as 5th rib
    • Right is higher than the left (due to liver)
  4. Discuss the functions of diaphram:
    • Separates abdominal cavity from thoracic cavity
    • Breathing: contraction of diaphram pulls central tendon inferiorly; flattens domes; increases thoracic capacity; lower intra-thoracic pressure; draws air into lungs
    • Pump: pumps venous blood up from below; same reason above
    • Abdominal straining: helps micturition, defecation, parturition
    • Weight lifting
  5. Describe the median arcuate ligament
    • Made of the medial borders of the crurae
    • Surrounds aorta
  6. Discuss the arcuate ligaments
    • Median arcuate ligament: arches over aorta
    • Pair of lateral arcuates: arch over quadratus lumborum
    • Pair of medial arcuates: arch over psoas
  7. What is the blood supply to the diaphram?
    • Blood supply is from superior and inferior phrenic arteries (from aorta)
    • Musculophrenic and pericardiophrenic arteries (from internal thoracic arteries)
  8. State the structures passing through the oesophageal opening
    • Oesophagus
    • Left and right vagus nerves
  9. Name structures that pass through the aortic hiatus
    • Aorta
    • Azygos vein
    • Hemiazygos vein
    • Thoracic duct
  10. Describe lymph drainage of the diaphram
    • Celiac
    • superior mesenteric nodes
    • Common iliac nodes
  11. True or false? The liver forms from the ventral mesentery
  12. True or false? The spleen forms from the ventral mesentary
    False! It forms from the dorsal mesentary
  13. What is lesser omentum?
    A bit of visceral peritoneum that runs from the lesser curvature of stomach to liver
  14. What and where is the epiploic foramen?
    • It’s a passageway between the greater sac and lesser sac
    • Located in the right free edge of the lesser omentum
  15. Describe the margins of the epipploic foramen
    • Anteriorly: Free edge of lesser omentum, which contains the Bile duct (right), Hepatic artery (left), Portal vein (behind and between them).
    • Posteriorly: Inferior vena cava
    • Superiorly: Caudate lobe of liver
    • Inferiorly: 1st part of duodenum
  16. Discuss the porta hepatis
    • Structures passing to the liver
    • Hepatic artery, portal vein, autonomic fibers
    • Structures passing out
    • Right and left hepatic ducts
    • Lymphatics
  17. What is the ampulla of Vater?
    Short duct which drains the bile duct and main pancreatic duct
  18. What is the sphincter of Oddi?
    It’s a sphincter around the distal bile duct, main pancreatic duct, and ampulla of Vater
  19. Name 4 major vessels of the abdomen
    • Abdominal aorta
    • Inferior vena cava
    • Azygos vein
    • Hemiazygos veins
  20. Describe the abdominal aorta
    • Enters the aortic hiatus at T12
    • Runs in front and to the left of Lumbar vertebrae
    • Splits into common ilac arteries at L4
    • Can be palpate just above umbilicus
  21. Describe the branches of Abdominal aorta!
    • Ventral
    • -- Celiac trunk
    • -- SMA
    • -- IMA
    • Lateral
    • -- Inferior phrenic
    • -- Middle Suprarenal
    • -- Renal
    • -- Testicular OR ovarian
    • Dorsal
    • -- Lumbar
    • -- Median Sacral
    • Terminal branches
    • -- Common iliacs
  22. Describe the Inferior vena cava
    • Formed from union of common iliacs at L5
    • Passes upwards on the right side of Aorta
    • Goes through central tendon of diaphram at T8
  23. Name the tributaries of the IVC
    • Common iliacs
    • (the left one recievs the median sacral)
    • Third and fourth lumbar
    • (1st and 2nd enter the 3rd)
    • Right gonadal vein
    • (left drains into left Renal vein)
    • Renal veins
    • Right supra renal
    • (left drains into left Renal)
    • Hepatic veins
  24. Discuss clinical significance of azygose and hemiazygos veins
    In blockage of IVC (like thrombosis) a connection is made between the IVC and SVC via these veins.
  25. Describe the Psoas muscle
    • Type: fusiform
    • Origins: lumbar vertebrae
    • Course: goes behind ingunal ligament and infront of hip joint
    • Insertion: lesser trochanter
    • Action: flexes trunk anteriorly and laterally, flexes hip and medially rotates hip
    • Nerve supply: lumbar plexus
  26. Describe the Illiacus
    • Shape: fan-shaped
    • Origin: ilac fossa
    • Insertion: Lesser trochanter
    • Innervation: femoral nerve (L2, L3)
    • Action: flexes hip
  27. Describe the Quadratus Lumborum
    • Type: strap
    • Origin: 12th rib
    • Insertion: ilac crest
    • Innervation: Lumbar plexus
    • Action: laterally flexes trunk
  28. Description of branches of the sacral plexus + details of Femoral and Obturator arteries
    • L1
    • -- Iliohypogastric
    • -- Ilioinguinal
    • L1, L2
    • -- Genitofemoral
    • L2, L3
    • -- Lateral cutaneous nerve of thigh
    • L2, L3, L4
    • -- Femoral nerve
    • ---- Emerges from lateral side of psoas, goes beneath inguinal ligament, into thigh, divides into:
    • ------ anterior: supplies skin over anterior thigh
    • ------ posterior: supply hip and knee joint, quadriceps, gives rise to:
    • -------- saphenous nerve: supplies skin on medial side of leg and foot
    • -- Obturator nerve
    • ---- Emerges from medial side of psoas, passes in front of sacro-iliac joint, through obturator canal, divides into:
    • ------ anterior and posterior: supplies adductors + supplies skin on medial thigh, hip, and knee joint
Card Set
Diaphragm and Posterior Abdominal Wall