Abdomen Week 3 Flashcards
Posterior Abdominal Wall (Supporting Bones)
- 11th and 12th rib
- T12; L1-L5 Vertebrae and Intervertebral discs
- Sacrum with interconnecting ligaments
Thoraco-lumbar and other fascia
Thoraco-lumbar fascia:
- Anterior layer covers Quadratus Lumborum
- Has middle and posterior layers
Psoas fascia
- Encloses Psoas Major muscle
- Inflammotory corrections track down and appear in groin where it is thinnest.
Iliac fascia
-Continuous with Psoas fascia
Perirenal fascia
-Multilaminated fascia over the kidneys, suprarenal gland, upper ureter and fat
Lateroconal fascia
-Lateral aspect of perirenal fascia that fuses with the fascia over transversus abdominus
Posterior Abdominal Wall (Muscles)
Psoas Major
- Superior Attachment
- Transverse process of 5 Lumbar Vertebrae
- 5 Intervertebral Discs (T12; L1-L5)
- Sides of bodies of T12; L1-L5
- Inferior Attachment
- By a strong tendon to lesser trochanter of the femur
- Innervation
- Anterior Rami of Lumbar nerves (Mainly L1-L2, L3 occasionally)
- Actions
- Acting inferiorly with Ilacus: Flexes thigh
- Acting Superiorly: Flexes vertebral column laterally
- Used to balance the trunk
- When sitting, acts inferiorly with Iliacus to flex the trunk
Iliacus
- Superior Attachment:
- Superior 2/3 of Iliac fossa
- Ala of sacrum
- Anterior sacroiliac ligaments
- Inferior Attachment:
- Lesser trochanter of the femur and shaft inferior to it
- Psoas major tendon
- Innervation:
- Femoral nerve
- Action:
- Flexes thigh and stabilises hip joint
- Acts with Psoas Major
Quadratus Lumborum
- Superior Attachment
- Medial half of inferior border of 12th ribs
- Tips of lumbar transverse processes
- Inferior attachment
- Iliolumbar ligament and inner lip of iliac crest
- Innervation
- Anterior branch of Subcostal and L1-L4 nerves
- Action
- Extends and laterally flexes vertebral column
- Fixes 12th rib during inspiration
Psoas Minor
- Superior Attachment
- Intervertebral disc between T12 and L1, and the adjacent aspects of their bodies
- Inferior Attachment
- Iliopubic eminence on pelvic brim
- Innervation
- Anterior branch of L1
- Action
- Weakly flexes the lumbar spine
Neurovasculature of Posterior Abdominal Wall
Nerves
- Lumbar Plexus (L1-L4)
- Numerous Autonomic Ganglia Plexuses
- Subcostal, Iliohypogastric and Ilioinguinal nerves
Vessels
Abdominal Aorta
Inferior Vena Cava
Lymphatics (Para-aortic lymph nodes)
Abdominal Aorta
Origin
-Passes diaphragm at T12
Termination
-L4, where it bifurcates into Left and Right Common Iliac Arteries
Branches (Unpaired - Superior to Inferior)
- Coeliac Artery
- Superior Mesentery Artery
- Inferior Mesentery Artery
- Median Sacral Artery
Branches (Paired - Superior to Inferior)
- Inferior Phrenic Arteries
- Middle Suprarenal Arteries
- Renal Arteries
- Gonadal Arteries
- Lumbar Arteries
- Common Iliac Arteries
Kidneys (Location)
- Posterior abdominal wall on each side of vertebral column and is retroperitoneal.
- Cranial end: T12, Caudal end: L3
- Right kidney usually lower than left.
- Left kidney is narrower and longer, and closer to the midline.
- Transpyloric plane passes through the superior part of the right kidney and inferior part of hilum of left kidney.
Kidneys (Colour, shape, size, weight)
- Reddish brown and bean-shaped.
- 11x6cm and Antero-posterior diameter: 3cm
- 150g in males, 135g in females
Kidneys (Surfaces and Borders)
- Has superior and inferior poles.
- Hilum on medial border.
- Has anterior and posterior surface.
Contents of the Hilum
Anterior- Posterior:
Renal Vein
Anterior Branch of Renal Artery
Ureter
Posterior Branch of Renal Artery
Relations of Kidney
Anterior (Right)
- Right suprarenal gland.
- Right lobe of liver.
- Hepatic Flexure
- Jejunum
- Descending Part of Duodenum
Anterior (Left)
- Left suprarenal gland
- Stomach
- Tail of Pancreas
- Spleen
- Left Colic Flexure
- Jejunum
Posterior
- Muscles:
- Thoracic Diaphragm
- Psoas Major
- Quadratus Lumborum
- Aponeurosis of Transversus Abdominis
- Nerves:
- Subcostal nerve
- Iliohypogastric
- Ilioinguinal
- Vessels:
- Subcostal vessels
Renal fascia and fat
Renal fascia:
- From subserous extraperitoneal fascia.
- Splits into colon and anterior layer(continue over renal vessels and aorta to join the opposite similar layer)and posterior layer (anterior to fascia on quadratus lumborum and psoas major to opposite site)
Perirenal fat/ Perinephric fat
-Mass of adipose fat between surface of kidney (capsule) and renal fascia (space of Gerota)
Pararenal/ Paranephric fat
- Considerable quantity of fat lying behind renal fascia.
- Fibrous and more in newborns than adults.
Interior of Kidney
- True Capsule: Tough, fibrous tissue
- Cortex overlies the base of the medullary pyramids and dipsdown between them as renal columns towards the renal sinus.
- Medulla: Innermost part of kidney with 8-18 pyramid masses(Pale, striated and conical. Apices towards renal sinus forming renal papillae into minor calyces then major calyces).
Arterial supply of kidney
Renal Arteries
- From abdominal aorta from L1-L2 intervertebral disc.
- Lies posterior to renal vein, body of pancreas and splenic vein.
- Inferior mesenteric vein crosses it anteriorly.
- Right renal artery is longer than the left.
- Lies behind the Inferior Vena Cava, right renal vein, head of pancreas an descending duodenum.
- Five segmental branches (Superior/Apical, Anterosuperior, Anteroinferior, Inferior and Posterior)
Venous drainage of kidney
Renal Veins
-Drain into Inferior Vena Cava
Left:
- Crosses anterior tpaorta just below superior mesenteric artery and opens into Inferior Vena Cava above right renal vien.
- Tributaries: Left phrenic, left testicular/ovarian, left suprarenal veins.
Right
-Lies anterior to renal artery but has no other renal tributaries
Lymphatics and Nerves of Kidney
Lymph Vessels
-Lateral Aortic lymph nodes
Nerves
-Renal Plexus
