Retroperitoneal Structures

Question 1

Boundaries of the Retroperitoneal Space

Answer 1

• Anterior: Parietal Peritoneum
• Lateral: Transversalis Fascia
• Posterior: Investing layers of Thoracolumbar Fascia

Question 2

Renal Fascia

Answer 2

• Surrounds kidneys, ureters, suprarenal glands, fat, major vessels

Question 3

Suprarenal Glands

Answer 3

• Superior to kidneys, weakly connected but functionally independent
• Endocrine, buried in perinephric fat
• Outer cortex (corticosteroids, androgens), inner medulla (catecholamines)

Question 4

Right Suprarenal Gland

Answer 4

Pyramid Shaped, related to:

• IVC
• Liver

Question 5

Left Suprarenal Gland

Answer 5

Crescent shaped, related to:

• Spleen
• Splenic Artery
• Pancreas
• Stomach
• Left crus of diaphragm

Question 6

Kidney

Answer 6

• Major organ of Urinary System
• Excretion of waste, excess solutes
• Resorption of nutrients
• Critical role in regulating blood volume and pressure
• Produces urine

Question 7

Position of kidneys

Answer 7

• Central back at costovertebral kidney

- Right kidney typically lower than left, only behind 12th rib where left is behind 11th and 12th ribs

Question 8

Renal Sinus

Answer 8

• Fat filled space continuous with perirenal space

- Passage for Renal A/V, Ureter, Nerves and lymphatics

Question 9

Ureters

Answer 9

Muscular tubes running along lumbar vertebrae, crossing external iliac artery, entering posterolateral urinary bladder

Question 10

Renal Calculi

Answer 10

• Kidney Stones

- Lodge in predictable places: Where ureters meet vertebrae, sacrum, and bladder

Question 11

Vasculature of Suprarenal Glands

Answer 11

• Superior Suprarenal Arteries - From inferior phrenic arteries
• Middle Suprarenal Arteries - From Aorta
• Inferior Suprarenal Arteries - from Renal Arteries
• Suprarenal Vein - to IVC

Question 12

Renal Vasculature

Answer 12

• Renal Arteries
• Renal Veins
  
  • Left Renal Vein drains Left Inferior Phrenic Vein and Left Testicular/Ovarian Vein

Question 13

Nutcracker Syndrome

Answer 13

• 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

Question 14

Suprarenal Glands Innervation

Answer 14

• Suprarenal Plexus
• derived mainly from thoracic splanchnic nerves and celiac ganglion
• preganglionic sympathetic fibers
• suprarenal medulla is essentially a sympathetic ganglion (that secretes hormones)

Question 15

Renal Innervation

Answer 15

• Renal Plexus
• derived from least splanchnic nerve (via aorticorenal ganglia), posterior vagal trunk
• visceral afferents follow T11-L2 segments
• Postganglionic sympathetics and preganglionic parasympathetics

Question 16

Posterior Abdominal Wall Muscles

Answer 16

• Quadratus Lumborum
• Psoas Major/Minor
• Iliacus

Question 17

Quadratus Lumborum

Answer 17

• O: iliac crest
• I: 12th rib, L1-L4
• Inn: vent rami of T12, L1-L4
• Act: lateral bending of trunk

Question 18

Psoas Major

Answer 18

• 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

Question 19

Psoas Sign

Answer 19

• Psoas muscles closely related to retrocecal appendix

- Pain upon contraction can help diagnosis of appendicitis

Question 20

Iliacus Muscle

Answer 20

• O: iliac fossa
• I: lesser trochanter of femur (as iliopsoas M)
• Inn: femoral N (L2-L4)
• Act: flexion, lat rotation at hip

Question 21

Psoas Minor

Answer 21

• Absent in 50% of people
• O: body of T12-L1
• I: iliopectineal arch
• Inn: lumbar plexus branches (L2-L4)
• Act: weak flexor of trunk

Question 22

Diaphragm

Answer 22

• 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]

Question 23

Lateral Arcuate Ligament

Answer 23

• passage of quadratus lumborum M, subcostal neurovascular bundle

Question 24

Medial Arcuate Ligament

Answer 24

• passage of psoas major M, sympathetic trunk

Question 25

Median Arcuate Ligament

Answer 25

- Forms Aortic Hiatus

Question 26

Caval Foramen

Answer 26

- IVC (level of T8)

Question 27

Esophageal Hiatus

Answer 27

- right crus | - Esophagus, vagal trunks (level of T10)

Question 28

Aortic Hiatus

Answer 28

- Aorta, Thoracic duct (level of T12)

Question 29

Which vessels of the Posterior Abdominal Wall are unpaired?

Answer 29

The Median Sacral Artery and Vein

Question 30

Posterior Abdominal Wall Arteries

Answer 30

- 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

Question 31

Posterior abdominal wall veins

Answer 31

- 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

Question 32

Cysterna Chyli

Answer 32

- drains lymphatics of abdominal cavity - located at L1-L2 - Drains into thoracic duct

Question 33

Lumbar Plexus

Answer 33

- Subcostal (T12) - Iliohypogastric (L1) - Ilioinguinal (L1) - Genitofemoral (L1-L2) - Lateral Femoral Cutaneous (L2-L3) - Femoral (L2-L4) - Obturator (L2-L4) - Lumbosacral Trunk (L4-L5)

Question 34

List the Structures of the Retroperitoneal Space

Answer 34

- Duodenum (part) - Pancreas (most) - Ascending/Descending Colon - Kidneys, ureters - Suprarenal Glands - Abdominal Aorta, IVC - Post Wall Muscles