Posterior Abdominal Wall

Front 1

Lumbar vertebrae and sacrum

Back 1

a. Superior portion of middle of posterior abdominal wall has bodies of five lumbar vertebrae

Front 2

Pelvic bones

Back 2

a. Ilia attach laterally to sacrum expanding outward to become iliac fossa

Front 3

Ribs

Back 3

a. Superiorly ribs 11-12 complete bony framework

Front 4

Psoas major muscle

Back 4

a. Passes through media arcuate ligament of diaphragm through abdomen and into thigh
b. Joins iliacus muscle in thigh→ common insertion

Front 5

Psoas major attachments

Back 5

c. Origin
i. Lateral aspect of bodies and anterior aspect of TP of T12-L5
d. Insertion
i. Lesser trochanter of femur

Front 6

Psoas major actions

Back 6

i. Flexion of thigh
ii. Flexion of vertebral column
iii. Unilateral flexion→ bending and rotation of torso to same side

Front 7

Psoas minor

Back 7

a. Lies on anterior surface of psoas major
b. Passes through medial arcuate ligament
c. Does not extend to thigh

Front 8

Psoas minor attachments

Back 8

d. Origin
i. Attaches to lateral aspect of the bodies of T12-L1
e. Insertion
i. Pectineal ine and iliopubic eminence

Front 9

Psoas minor action

Back 9

i. Weak flexor of vertebral column

Front 10

Psoas minor innervation

Back 10

i. Anterior rami of L1

Front 11

Quadratus lumborum

Back 11

a. Deep and lateral to psoas major
b. Between 12th rib and iliac crest

Front 12

Quadratus lumborum attachments

Back 12

c. Origin
i. TP of LV
ii. Iliolumbar ligaments
iii. Iliac crest
d. Insertion
i. TP of L1-L4
ii. Inferior border of rib 12

Front 13

Quadratus lumborum action

Back 13

i. Weak lateral flexor of torso

Front 14

Quadratus lumborum innervation

Back 14

i. Anterior rami of T12-L4

Front 15

Iliacus

Back 15

a. Superiorly, fills deep surface of ilium
b. Inferiorly, joins psoas major to form iliopsoas

Front 16

Iliacus attachments

Back 16

i. Arises from upper 2/3 of iliac fossa
ii. Anterior sacroiliac
iii. Iliolumbar ligaments
iv. Superior lateral surface of sacrum
d. Insertion
i. Lesser trochanter of femur

Front 17

Iliacus action

Back 17

i. Flexion of thigh

Front 18

Iliacus innervation

Back 18

i. Femoral nerve (L2-L4)

Front 19

Diaphragm

Back 19

a. Large central tendon
b. Right→ 5th rib
c. Left→ 5th intercostal space

Front 20

Sternal region of diaphragm

Back 20

1. Small muscular attachment to deep surface of sternum

Front 21

Costal region of diaphragm

Back 21

1. Attaches to deep surface of ribs and costal cartilages of inferior thoracic aperture

Front 22

Lumbar region of diaphragm

Back 22

1. Attaches to deep surface of TP of L1
2. Anterior surface of L1-L2 on left
3. L1-L4 on right

Front 23

Lateral arcuate ligament

Back 23

i. Between attachment on 12th rib and TP of L1
ii. Allows passage of quadratus lumborum and posterior abdominal wall

Front 24

Medial arcuate ligament

Back 24

i. Between attachment of TP of L1 and attachments to vertebral bodies
ii. Allows passage of psoas muscles, sympathetic trunk, and least splanchnic nerve

Front 25

Right crus

Back 25

i. Right attachment to anterior aspect of L1-L3
ii. Splits at T10→ esophageal hiatus

Front 26

Left crus

Back 26

i. Left attachment to anterior aspect of L1-L2

Front 27

Median arcuate ligament

Back 27

i. Left and right crura union
ii. Aortic hiatus (T12)

Front 28

Inferior vena cava

Back 28

i. Passes through at T8 in caval foramen

Front 29

Blood supply to superior surface of diaphragm

Back 29

i. Branches of internal thoracic arteries
ii. Pericardiophrenic and musculophrenic
iii. Superior phrenic arteries (branch of abdominal aorta)

Front 30

Blood supply to inferior surface of diaphragm

Back 30

i. Inferior phrenic arteries

Front 31

Venous drainage of diaphragm

Back 31

i. Mirrors arterial supply

Front 32

Transversalis fascia

Back 32

a. Lines internal abdominal wall and inferior surface of diaphragm
b. Includes anterior thoracolumbar fascia dn iliac fascia
c. External to parietal peritoneum

Front 33

Posterior layer of thoracolumbar fascia

Back 33

i. Divides structures of superifical and deep back
ii. Forms attachment sites for muscles of superficial back and abdominal wall
iii. Lat dorsi, serratus posterior inferior, external oblique, transverses abdominis

Front 34

Middle layer of thoracolumbar fascia

Back 34

i. Divides posterior abdominal wall from back

Front 35

Anterior layer of thoracolumbar fascia

Back 35

i. Invests muscles of posterior abdominal wall

Front 36

Quadratus lumborum fascia

Back 36

1. Covers anterior surface of quadratus lumborum muscle

Front 37

Psoas fascia

Back 37

1. Surrounds and separates psoas major and minor muscles
2. Continues inferiorly with iliac fascia

Front 38

Iliac fascia

Back 38

1. Covers internal surface of iliacus muscle and psoas major
2. Continuous superiorly with psoas fascia

Front 39

Abdominal aorta

Back 39

a. Passes through median arcuate ligament of diaphragm on anterior surface of T12

Front 40

Visceral branches of abdominal aorta

Back 40

i. Unpaired
ii. Travels through mesentery to organs within peritoneal cavity

Front 41

Parietal branches of abdominal aorta

Back 41

i. Paired

Front 42

Common iliac arteries

Back 42

i. Branches off abdominal aorta at L4
ii. Supplies majority of pelvis and lower limb

Front 43

Celiac artery

Back 43

i. Unpaired
ii. Arises at T12
iii. Supplies spleen, stomach, part of pancreas, duodenum, gallbladder, and liver (foregut)

Front 44

Superior mesenteric artery

Back 44

i. Unpaired
ii. Arises at L1
iii. Supplies a portion of pancreas, small intestine, cecum, appendix, ascending colon, right half of transverse colon (midgut)

Front 45

Inferior mesenteric artery

Back 45

i. Unpaired
ii. Arises at L3
iii. Supplies left half of transverse colon, descending colon, sigmoid colon, superior rectum (hindgut)

Front 46

Middle suprarenal arteries

Back 46

i. Paired
ii. Arise at L1

Front 47

Renal arteries

Back 47

i. Paired
ii. Arise at L1-L2

Front 48

Gonadal arteries

Back 48

i. Paired
ii. Arise at level of L2

Front 49

Inferior phrenic arteries

Back 49

i. Paired
ii. Arise at T12
iii. Supplies inferior surface of diaphragm

Front 50

Lumbar arteries

Back 50

i. Paired
ii. Arise from posterior aspect of abdominal aorta at vertebral level of segment of body wall that they supply

Front 51

Median sacral artery

Back 51

i. Unpaired
ii. Arises in midline on the posterior aspect of aorta just above bifurcation into common iliac arteries (L4)

Front 52

Inferior vena cava

Back 52

a. Arises from confluence of right and left common iliac veins at L5
b. Descend on right of abdominal aorta
c. Does not contain blood from GI tract
d. Posterior to liver

Front 53

Lumbar veins

Back 53

1. Paired
2. Join IVC at corresponding vertebral level
3. Lumbar veins 1-2
a. Connects that form ascending lumbar vein
b. Drains into azygos system of veins

Front 54

Right gonadal vein

Back 54

1. Joins IVC at L2

Front 55

Left gonadal vein

Back 55

1. Drains into left renal vein

Front 56

Renal veins

Back 56

1. Paired
2. Join IVC at L1/L2

Front 57

Left renal vein

Back 57

1. Passes anterior to the aorta
2. Posterior to SMA
3. Nutcracker syndrome

Front 58

Right suprarenal vein

Back 58

1. Joins IVC at T12

Front 59

Left suprarenal vein

Back 59

1. Drains into left renal vein

Front 60

Hepatic veins

Back 60

1. Join IVC before passage through caval foramen
2. Veins contain blood from abdominal GI tract

Front 61

Inferior phrenic veins

Back 61

1. Paired
2. Joins IVC at T8
3. Passes through diaphragm

Front 62

Iliohypogastric nerve

Back 62

a. L1
b. Courses along anterior surface of quadratus lumborum
c. Pierces transverses abdominis
d. Courses between transverses abdominis and internal oblique
e. Supplies branches to abdominal musculature

Front 63

Cutaneous branches of iliohypogastric nerve

Back 63

i. Lateral cutaneous
1. Posterolateral gluteal skin
ii. Anterior cutaneous
1. Skin over pubic region

Front 64

Ilioinguinal nerve

Back 64

a. L1
b. Courses inferiorly to iliohypogastric
c. Anterior surface of quadratus lumborum
d. Supplies cutaneous innervation to superior medial thigh, root of penis, and anterior scrotum
e. Mons pubis and labium majora in women

Front 65

Genitofemoral nerve

Back 65

a. L1-L2

Front 66

Genital branch of genitofemoral nerve

Back 66

i. Enters inguinal canal
ii. Innervates cremasteric muscle
iii. Skin over superior anterior scrotum
iv. Women→ continues with round ligament of uterus and ends on skin of mons pubis and labium majora

Front 67

Femoral branch of genitofemoral nerve

Back 67

i. Descends past external iliac artery
ii. Posterior to inguinal ligament
iii. Enters femoral sheath
iv. Supplies skin of superior anterior thigh

Front 68

Lateral cutaneous nerve of thigh

Back 68

a. L2-L3
b. LCN receives sensory information from skin over the antieor/lateral thigh to level of knee

Front 69

Obturator nerve

Back 69

a. L2-L4
b. Emerges from medial border near pelvic brim
c. Courses with common iliac vessels
d. Passes through obturator foramen into medial compartment of thigh

Front 70

Femoral nerve

Back 70

a. L2-L4
b. Emerges form lateral border of psoas major anterior to iliacus
c. Courses along border between psoas major and iliacus
d. Passes posterior to inguinal ligament into anterior compartment of thigh