Posterior abdominal wall

Question 1

Overview of structures

Answer 1

1. bony components
2. Muscles and fascia
3. Structures

Question 2

Bony components

Answer 2

5 lumbar vert and IVD’s

Question 3

Muscles and fascia

Answer 3

Psoas major & minor, iliacus, quadratus lumborum, transversus abdominus, diaphragm

Question 4

Structures

Answer 4

Nerves
Arteries
Veins
Lymphatics

Middle of posterior abdominal wall, mostly close to bodies of lumbar vertebrae

Question 5

How many lumbar vert?

Answer 5

5

Question 6

Spines of lumbar vert are

Answer 6

short and horizontal

Question 7

bodies of lumbar vert are

Answer 7

large and kidney
shaped: weight bearing

Question 8

Facets orientation of lumbar vert allows:

Answer 8

flexion, extension and lateral
flexion, no rotation.

Question 9

Question 10

Question 11

Question 12

Question 13

Question 14

Pelvic brim (inlet)

Answer 14

Extends from the sacral promontory posteriorly to the symphasis pubis anteriorly

Question 15

Pelvis major is the part of the pelvis

Answer 15

Located superior to the pelvic brim
- abdominal structures

Question 16

Pelvic minor is the part of the pelvis

Answer 16

Located inferior to the pelvic brim
- pelvic organs

Question 17

Three parts of the pelvic brim are:

Answer 17

• Anterior border of the ala of the sacrum (sacral part)
• Arcuate line of the ilium (iliac part)
• Pecten pubis and pubic crest (pubic part)

Question 18

The pelvis has 4 articulations

Answer 18

• Two synovial joints
  [ Sacroiliac joints]
• Two symphysis joints (symphysis pubis and sacrococcygeal joint)

Question 19

Sacrum & coccyx consist of

Answer 19

Five fused vertebrae.

Question 20

Sacrum & coccyx features

Answer 20

Triangular with apex inferior (articulates
with coccyx).
* Base superior (body articulates with L5).
* Ala laterally (represents transverse processes).
* Concave anterior surface & convex posterior surface.
* Anterior and posterior sacral foramina: for anterior & posterior rami of spinal nerves.
* Auricular surface: articulates with pelvic bones.
* Sacral hiatus (injection of anesthetic).
* Coccyx: 3 or 4 fused vertebrae.

Question 21

Question 22

Answer 22

Psoas major

Question 23

Psoas major origin/prox:

Answer 23

lateral surface of bodies, intervertebral discs and transverse processes of lumbar vertebrae (& T12)

Question 24

Psoas major insertion/distal:

Answer 24

lesser trochanter of femur

Question 25

Psoas major innervation

Answer 25

Anterior rami of L1, L2, L3

Question 26

Psoas major action

Answer 26

Flexes thigh at hip

Question 27

Answer 27

Psoas minor

Question 28

Psoas minor origin/prox:

Answer 28

lateral surface of bodies of T12 & L1, intervertebral disc

Question 29

Psoas minor insertion/distal:

Answer 29

Pectineal line, iliopubic eminence

Question 30

Psoas minor innervation

Answer 30

Anterior rami of L1

Question 31

Psoas minor action

Answer 31

weak flexor of vertebral column

Question 32

Answer 32

Quadratus lumborum

Question 33

Quadratus lumborum origin/prox:

Answer 33

Transverse process of L5, iliolumbar ligament, iliac crest

Question 34

Quadratus lumborum insertion/distal:

Answer 34

Transverse processes of L1-L4, inferior border of rib 12

Question 35

Quadratus lumborum innervation

Answer 35

Anterior rami of T12, L1, L2, L3, L4

Question 36

Quadratus lumborum action

Answer 36

Depresses and stabilizes rib 12, lateral flexion of trunk.

Question 37

Answer 37

Iliacus

Question 38

Iliacus prox:

Answer 38

anterior iliac fossa of os coxa

Question 39

Iliacus distal:

Answer 39

Anterior lesser trochanter of femur

Question 40

Iliacus innervation

Answer 40

Femoral nerve

Question 41

Iliacus action

Answer 41

Flexes thigh at hip

Question 42

Diaphragm * Position varies (breathing, posture, abdominal viscera).

Question 43

Diaphragm Structure & attachments:

Answer 43

* Central tendon * Surrounding muscular part Sternal Costal Lumbar

Question 44

Median, medial and lateral arcuate ligaments of diaphragm

Question 45

* Blood supply (inferior surface) of diaphragm

Answer 45

inferior phrenic arteries & veins

Question 46

Nerve supply of diaphragm:

Answer 46

phrenic nerves (C3, C4, C5).

Question 47

Question 48

Diaphragm * Openings

Answer 48

* Caval opening: IVC: T8 * (O)Esophageal hiatus: T10 * Aortic hiatus: T12

Question 49

Question 50

Retroperitoneal space:

Answer 50

behind peritoneum.

Question 51

Retroperitoneal structures:

Answer 51

peritoneum on anterior side only.

Question 52

Fascia lining posterior abdominal wall is continuous

Answer 52

with fascia that lines transversus abdominis muscle.

Question 53

Retroperitoneal fascia * Lies between parietal peritoneum & muscles. * Named according to structure it covers:

Answer 53

o Psoas fascia: * Forms medial arcuate ligament - thickening of fascia. * Fuses laterally with quadratus lumborum and thoracolumbar fascias. * Continuous inferiorly with iliac fascia. o Quadratus lumborum fascia (anterior layer of thoracolumbar fascia). * Forms lateral arcuate ligament.

Question 54

Structures on posterior abdominal wall Nerves

Answer 54

lumbar plexus, sympathetic nerves.

Question 55

Structures on posterior abdominal wall Arteries

Answer 55

Abdominal aorta & branches.

Question 56

Structures on posterior abdominal wall Veins

Answer 56

Inferior vena cava & tributaries.

Question 57

Structures on posterior abdominal wall Lymph nodes

Question 58

Lumbar plexus

Answer 58

Question 59

Question 60

Question 61

https://www.youtube.com/watch?v=RYk7rbgK1Z4

Question 62

Abdominal Aorta

Answer 62

* Starts at T12 – aortic hiatus. * Ends at L4 – bifurcation into left and right common iliac arteries. * Anterior to vertebral bodies, IVC on right hand side. * Left lumbar veins pass posterior to aorta. * Common iliac arteries – medial border of psoas major to pelvic brim: * Divide into external and internal iliac arteries.

Question 63

Abdominal Aorta - Branches Three vascular planes:

Answer 63

1. Anterior midline - Unpaired visceral branches – digestive system – celiac, superior mesenteric, inferior mesenteric arteries. 2. Lateral - Paired visceral branches – urogenital and endocrine organs – suprarenal, renal, gonadal arteries. 3. Posterolateral – Paired parietal branches – diaphragm, body wall – subcostal, inferior phrenic, lumbar arteries

Question 64

Inferior Vena Cava

Answer 64

* Begins anterior to L5: union of common iliac veins. * Ascends on right side of L3, L4 &L5 vertebral bodies, on the right psoas major, on the right of the aorta. * Passes through the caval opening of the diaphragm at T8. * Tributaries: correspond to the paired visceral and paired parietal branches of abdominal aorta. * Unpaired branches from digestive tract – hepatic portal vein. * Left inferior phrenic & left gonadal vein drain into left renal vein. * Ascending lumbar & azygous veins connect IVC and SVC.

Question 65

Lymphatic drainage

Answer 65

* Lymph nodes & lymphatic vessels – lie along aorta, IVC, and iliac vessels. * Common iliac nodes: lymph from external & internal lymph nodes --> lumbar lymph nodes. * Lymph from digestive organs: pre- aortic lymph nodes:celiac, superior mesenteric, inferior mesenteric (around the origins of the arteries). * Intestinal lymphatic trunks: pre-aortic nodes. * Lumbar lymphatic trunks: from lumbar nodes. * Thoracic duct: all the lymph from below the diaphragm. ➢Inferior end – dilation called cisterna chyli – anterior to L1, L2. ➢Ascends through aortic hiatus in diaphragm. ➢Ultimately enters venous system: junction of left subclavian & internal jugular veins.

Question 66

Question 67

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