Posterior abdominal wall and the great vessels

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Posterior abdominal wall and the great vessels

Prof. Dr. Selda Önderoğlu

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Post abdominal wall

• Ribs

• Lumbar vertebrae

• Muscles; psoas, quadratus lumborum, iliacus,

• Lumbar plexus

• Fascia; including

thoracolumbar fascia

• Diaphragm

• Extraperitoneal fatty tissue, vessels, nn., lymph nodes

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Fascia

A- Iliac fascia

• Covers iliacus, psoas major and psoas

minor mm.

• Called Psoas fascia (the part covering psoas major and

minor- Forms medial arcuate lig.

• Thickens through inguinal lig

• Inferiorly, fascia lata

B- fascia of quadratus

lumborum m.

Lateral arcuate lig.

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Thoracolumbar fascia

• Covers deep mm. of back,

• 3 layers

• Post layer: Attached to

spinous processes of lumbar and sacral vertebrae

• Middle layer : Attached to transverse processes of

lumbar vertebrae, iliac crest, 12th rib

• Ant layer :Forms fascia covering quadratus lumborum m.

• Middle and post layers unite at lateral border of erector spinae

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Quadratus lumborum m.

• O: rib 12

• I: iliac crest, transverse

processes of upper 4 L vertebrae

• N: Subcostal n.&lumbar plexus

• F: Fixes 12th rib. Acts as a

muscle of inspiration by helping to stabilize lower attachments of diaphragm.

-If pelvis is fixed; flexes vertebral column to the same side.

-If both mm. contract; extend lumbar part of vertebral column

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Ant. relations of quadratus lumborum m.

• Ascending colon

• Descending colon

• Kidneys

• Psoas major m.

• Psoas minor m.

• Diaphragm

• Subcostal n.

• Iliohypogastric n.

• Ilioinguinal n.

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Iliopsoas muscle

• Psoas major m.

• Psoas minor m.

• Iliacus m.

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Psoas major m.

• O: L1-L5

• I: Lesser trochanter

(together with iliacus m.)

• N: lumbar plexus

• F: Together with iliacus, most powerful flexor of thigh.

• If lower extremity is fixed, flexes vertebral column

• Courses post to inguinal lig

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• Emerging from lateral border of psoas major:

-iliohypogastric n.

-ilioinguinal n.

-lateral femoral cutaneous n.

-femoral n.

• Medial border;

-obturator n.

-accessory obturator n.

- upper 4 roots of lumbosacral trunk

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Psoas minor m.

• O: T-12, L-1

• I:Pecten pubis, iliopectineal eminence,

• N: Ventral ramus of L-1

• F: Helps flexion of trunk (weak)

• 40% absent

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Iliacus m.

• O: iliac fossa, iliac crest, sacrum

• I: Lesser trochanter

• N: Femoral n.

• F: Together with

psoas major: flexion and lat rotation of thigh.

– If lower extremity is fixed: flexion of trunk

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Relations of iliacus m.

• Ant; lateral

femoral cutaneous n.

• Med; psoas major, femoral n.

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Aa. of post abdominal wall (subcostal+lumbar aa)

Subcostal a.

• 12th post intercostal a.

• Last branch of thoracic aorta

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Lumbar aa.

• 4 pairs

• Originates from abdominal aorta

• Has 2 branches:

1-Dorsal branch: dorsal mm., joints, skin

2-Spinal branch: enters

vertebral canal, supplies

structures in vertebral canal

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Veins of post abdominal wall(Lumbar vv.

+ascending.lumbar v.)

• 4 or 5 pairs

• Post branches

anastomose with vertebral venous plexus

• Join each other by ascending lumbar v.

• Drain into: inf v. Cava

& ascending lumbar v.

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Ascending lumbar v.

• Joins common iliac v., iliolumbar v.& lumbar vv.

• Superiorly, joins with subcostal vv.

• Courses through

diaphragm; reaches thoracic cavity

• Right drains into:

azygos v.

• Left into: hemiazygos v.

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Nn. of post abdominal wall ( subcostal n.+lumbar pl.)

Subcostal n.

• Ventral ramus of 12th thoracic spinal n.

• Passes post to lat arcuate lig(diaphragm)

• Courses; between

• transversus abdominis –

obliquus internus abdominis mm.

• Descends as far as the gluteal region (skin area)

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Lumbar Plexus

• Post to psoas major m.

• Ventral rami of T-12 (a branch), L1-L3 and most of L4

• Muscular branches;

quadratus lumborum,

psoas major, psoas minor, iliacus

• Iliohypogastric n.

• Ilioinguinal n.

• Genitofemoral n.

• Lat femoral cutaneous n.

• Femoral n.

• Obturator n.

• Accessory obturator n.

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Sympathetic trunk- lumbar part

• 4 interconnected ganglia

• Place:Runs ant to vertebral column, along medial margin of psoas major

• Course: post to medial arcuate lig-

Enters thor.cavity

• 4 lumbar splanchnic nn. from ganglia to join coeliac,

intermesenteric, sup hypogastric plexuses

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Lymphatic vessels

• Located around

abdominal aorta, inf v.

cava, common iliac a.v.

• Lumbar (aortic) lymph nodes (lymph from

post abdominal wall, kidneys, ureters, testis, ovarium, uterus,

uterine tube drain)

• Aortic lymph nodes  Right and left lumbar lymphatic trunks  in thorax continues as Cisterna chyli

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Inf vena cava

• Greatest v. in the body

• Retroperitoneal

• Conveys blood to right atrium from abdomen, pelvis, lower

extremities, external genital organs

• Begins :L5, right and left common iliac vv.

unite  inf v. cava

• On the right side of abdominal aorta

• on the medial side of psoas major

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• At T-8, central tendon of

diaphragm

• Opening for inf.

Vena cava

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Ant relations of inf v. cava

• Parietal peritoneum

• Right common iliac a.

• Root of mesentery

• Right testicular (ovarian) a.

• Horizontal part of duodenum

• Head of pancreas

• Epiploic Foramen

• Posterior surface of liver

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Vv. draining

into inf v. cava

• Inf phrenic vv.

• Lumbar vv.

• Common iliac vv.

• Hepatic vv.

• Renal vv.

• Right suprarenal v.

• Right testicular (ovarian ) v.

R

R R

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Lumbar vv.

• 4 pairs

• Collect blood from lumbar mm., skin (dorsal tributaries), wall of abdomen

(abdominal tributaries)

• Left ones longer

• Lumbar v. 1: Joins with lumbar v. 2 or

ascending lumbar v., indirectly opens to inf v. cava

• Lumbar v. 2: Drains to ascending lumbar v. or inf v. cava

• Lumbar vv. 3-4: Drains directly to inf v. cava