Retroperitoneal Structures Flashcards
Boundaries of the Retroperitoneal Space
- Anterior: Parietal Peritoneum
- Lateral: Transversalis Fascia
- Posterior: Investing layers of Thoracolumbar Fascia
Renal Fascia
- Surrounds kidneys, ureters, suprarenal glands, fat, major vessels
Suprarenal Glands
- Superior to kidneys, weakly connected but functionally independent
- Endocrine, buried in perinephric fat
- Outer cortex (corticosteroids, androgens), inner medulla (catecholamines)
Right Suprarenal Gland
Pyramid Shaped, related to:
- IVC
- Liver
Left Suprarenal Gland
Crescent shaped, related to:
- Spleen
- Splenic Artery
- Pancreas
- Stomach
- Left crus of diaphragm
Kidney
- Major organ of Urinary System
- Excretion of waste, excess solutes
- Resorption of nutrients
- Critical role in regulating blood volume and pressure
- Produces urine
Position of kidneys
- Central back at costovertebral kidney
- Right kidney typically lower than left, only behind 12th rib where left is behind 11th and 12th ribs
Renal Sinus
- Fat filled space continuous with perirenal space
- Passage for Renal A/V, Ureter, Nerves and lymphatics
Ureters
Muscular tubes running along lumbar vertebrae, crossing external iliac artery, entering posterolateral urinary bladder
Renal Calculi
- Kidney Stones
- Lodge in predictable places: Where ureters meet vertebrae, sacrum, and bladder
Vasculature of Suprarenal Glands
- Superior Suprarenal Arteries - From inferior phrenic arteries
- Middle Suprarenal Arteries - From Aorta
- Inferior Suprarenal Arteries - from Renal Arteries
- Suprarenal Vein - to IVC
Renal Vasculature
- Renal Arteries
- Renal Veins
- Left Renal Vein drains Left Inferior Phrenic Vein and Left Testicular/Ovarian Vein
Nutcracker Syndrome
- Left Renal Vein runs between Superior Mesenteric Artery and Aorta, can become compressed
- Leads to increase of blood pressure in left urinogenital organs
- Think nutcracker bc it hurts your balls real bad
Suprarenal Glands Innervation
- Suprarenal Plexus
- derived mainly from thoracic splanchnic nerves and celiac ganglion
- preganglionic sympathetic fibers
- suprarenal medulla is essentially a sympathetic ganglion (that secretes hormones)
Renal Innervation
- Renal Plexus
- derived from least splanchnic nerve (via aorticorenal ganglia), posterior vagal trunk
- visceral afferents follow T11-L2 segments
- Postganglionic sympathetics and preganglionic parasympathetics
Posterior Abdominal Wall Muscles
- Quadratus Lumborum
- Psoas Major/Minor
- Iliacus
Quadratus Lumborum
- O: iliac crest
- I: 12th rib, L1-L4
- Inn: vent rami of T12, L1-L4
- Act: lateral bending of trunk
Psoas Major
- O: transverse processes/bodies of T12-L5
- I: lesser trochanter of femur (as iliopsoas M)
- Inn: lumbar plexus branches (L2-L4)
- Act: flexion, lat rotation at hip; lat bending, flexion of trunk
Psoas Sign
- Psoas muscles closely related to retrocecal appendix
- Pain upon contraction can help diagnosis of appendicitis
Iliacus Muscle
- O: iliac fossa
- I: lesser trochanter of femur (as iliopsoas M)
- Inn: femoral N (L2-L4)
- Act: flexion, lat rotation at hip
Psoas Minor
- Absent in 50% of people
- O: body of T12-L1
- I: iliopectineal arch
- Inn: lumbar plexus branches (L2-L4)
- Act: weak flexor of trunk
Diaphragm
- Muscular dome with central tendon, separates thoracic and abdominopelvic cavities
- O: ribs 7-12, costal cartilages, xiphoid, bodies of L1-L3 (crura)
- I: central tendon
- Inn: phrenic N (C3-C5)
- Act: depresses floor of thoracic cavity, compresses abdominal cavity - Crura form tendinous arches]
Lateral Arcuate Ligament
- passage of quadratus lumborum M, subcostal neurovascular bundle
Medial Arcuate Ligament
- passage of psoas major M, sympathetic trunk
Median Arcuate Ligament
- Forms Aortic Hiatus
Caval Foramen
- IVC (level of T8)
Esophageal Hiatus
- right crus
- Esophagus, vagal trunks (level of T10)
Aortic Hiatus
- Aorta, Thoracic duct (level of T12)
Which vessels of the Posterior Abdominal Wall are unpaired?
The Median Sacral Artery and Vein
Posterior Abdominal Wall Arteries
- Parietal Arteries:
- Inf phrenic A: supply diaphragm, suprarenal glands, esophagus
- Lumbar AA (typically 4-5 pairs): supply wall, MM
- Gonadal Artery: supply gonads
- Common Iliac Artery: Supply lower limb, pelvic cavity
- Median Sacral Artery: Pelvic Wall
- Subcostal artery
Posterior abdominal wall veins
- all drain into IVC except L gonadal vein (which drains into the renal vein) and the ascending lumbar veins, which drain into the azygous/hemiazygous veins
Cysterna Chyli
- drains lymphatics of abdominal cavity
- located at L1-L2
- Drains into thoracic duct
Lumbar Plexus
- Subcostal (T12)
- Iliohypogastric (L1)
- Ilioinguinal (L1)
- Genitofemoral (L1-L2)
- Lateral Femoral Cutaneous (L2-L3)
- Femoral (L2-L4)
- Obturator (L2-L4)
- Lumbosacral Trunk (L4-L5)
List the Structures of the Retroperitoneal Space
- Duodenum (part)
- Pancreas (most)
- Ascending/Descending Colon
- Kidneys, ureters
- Suprarenal Glands
- Abdominal Aorta, IVC
- Post Wall Muscles
