Posterior Abdominal Wall Musculature, Vasculature, and Lymphatics

Question 1

What muscles make up the posterior abdominal wall?

Answer 1

> Psoas major
> Psoas minor 
> Quadratus lumborum 
> Transversus abdominis 
> Iliacus

Question 2

What is the origin and insertion of the Psoas major?

Answer 2

Origin - lateral aspects and transverse processes of vertebral bodies and discs of T12-L5.

Insertion - lesser trochanter of femur via common tendon with iliacus (iliopsoas tendon).

Question 3

What is the innervation of the Psoas major muscle?

Answer 3

L2-L4 via lumbar plexus

Question 4

What is the action of the Psoas major muscle?

Answer 4

> Flexes thigh at hip
With feet fixed flexes trunk on thigh (at the hip joint)
Acting unilaterally = side bends trunk to same side.

Question 5

What is muscle is the primary hip flexor?

Answer 5

Psoas major

Question 6

What is the origin and insertion of the psoas minor muscle?

Answer 6

Origin - lateral aspects of bodies of T12 and L1, plus their intervening discs.

Insertion - pectineal line on superior ramus of pubis.

Question 7

Where does the innervation for the psoas minor muscle come from?

Answer 7

Major Contribution - L1

Somtimes L2

Question 8

What is the action of the psoas minor muscle?

Answer 8

> assists in extension and flexion of trunk

> acting unilaterally = side-bends trunk to same side.

Question 9

What muscle is the most lateral muscle of the posterior abdominal wall?

Answer 9

quadratus lumborum

Question 10

What is the origin and insertion of the quadratus lumborum muscle?

Answer 10

Origin - iliac crest and iliolumbar ligament

Insertion - medial half of inferior border of 12th rib and tips of lumbar transverse processes

Question 11

Where does the innervation for the quadratus lumborum come from?

Answer 11

T12-L4

Question 12

What is the action of the quadratus lumborum muscle?

Answer 12

> Extends and laterally flexes vertebral column.

> Fixes rib 12 during inspiration.

Question 13

What muscle of the posterior abdominal wall muscles fixes the 12th rib during inspiration?

Answer 13

quadratus lumborum

Question 14

What is the origin and insertion of the iliacus muscle?

Answer 14

Origin - iliac fossa of pelvis.

Insertion - lesser trochanter of femur via common iliopsoas tendon.

Question 15

What is the innervation of the iliacus muscle?

Answer 15

Femoral N. (L2-L4)

Question 16

What is the action of the iliacus muscle?

Answer 16

> Flexes thigh at hip.

> With lower limb fixed - flexes pelvis on thigh.

Question 17

When the lower limb is fixed, what action does the iliacus have?

Answer 17

Flexes pelvis on thigh.

Question 18

How far does the superior surface of the respiratory diaphragm extend upward?

Answer 18

As far as 5th rib.

Question 19

What are the boundaries of the respiratory diaphragm?

Answer 19

• xiphisternal joint
• costal margin
• body of T12

Question 20

What are the three peripheral origins that insert on the central tendon?

Answer 20

• sternal origin
• costal origin
• lumbar origin

Question 21

Is the right or left crus longer?

Answer 21

Right curs is longer. Left crus is shorter.

Question 22

At what landmark do the right and left crus meet?

Answer 22

Meet at aortic hiatus.

Question 23

What do posterior origins of the diaphragm form?

Answer 23

Arcuate ligaments over posterior wall structures.

Question 24

What major vessel does the median arcuate ligament go over?

Answer 24

over aorta

Question 25

What does the medial arcuate ligament go over?

Answer 25

- over psoas major mm. | - sympathetic trunks

Question 26

What ligament goes over the psoas major mm. and the sympathetic trunks?

Answer 26

medial arcuate ligaments

Question 27

What ligament goes over the aorta?

Answer 27

median arcuate ligaments

Question 28

What do the lateral arcuate ligaments go over?

Answer 28

- over quadratus lumborum | - subcostal nn, aa, and vv.

Question 29

What is another name for the arcuate ligaments?

Answer 29

Lumbocostal arches: > median lumbocostal arch > medial lumbocostal arch > lateral lumbocostal arches

Question 30

Where is a potential site of hernias in the abdominal cavity?

Answer 30

Vertebrocostal (lumbocostal) Triangle

Question 31

At what vertebra level is the aortic hiatus?

Answer 31

T12

Question 32

What passes through the aortic hiatus?

Answer 32

- aorta | - thoracic duct

Question 33

At what vertebra level is the esophageal hiatus?

Answer 33

T10

Question 34

What passes through the esophageal hiatus?

Answer 34

- esophagus - esophageal branches of left gastric a. - anterior and posterior Vagal trunks - lymphatics

Question 35

At what vertebra level is the vena caval foramen?

Answer 35

T8

Question 36

What passes through the vena caval foramen?

Answer 36

- inferior vena cava - terminal branches of right phrenic nerve - lymphatics from the liver

Question 37

What passes through the sternocostal hiatus?

Answer 37

superior epigastric vessels

Question 38

What is the only motor nerve that goes to the diaphragm?

Answer 38

phrenic nerve (C3,4,5)

Question 39

What do the branches of the phrenic nerve run with on its way to the diaphragm?

Answer 39

inferior phrenic artery

Question 40

The phrenic nerve is the motor supply to the diaphragm, but what does it carry with it to the diaphragm?

Answer 40

Phrenic nerve carries sensory nn. from central tendon.

Question 41

What other nerve carries sensory fibers from the peripheral part of the diaphragm?

Answer 41

Intercostal nn. carries sensory fibers from peripheral part.

Question 42

True or False: | We have both parietal and visceral lymphatics.

Answer 42

True

Question 43

What are the nerves of the posterior abdominal wall?

Answer 43

- subcostal (L1) - iliohypogastric (L1) - ilioinguinal (L1) - lateral cutaneous nerve of thigh (L2,3) - genitofemoral nerve (L1,2) - femoral (L2 -L4) - obturator nerve (L2-L4)

Question 44

At what vertebra level does the aorta typically bifurcate?

Answer 44

L4

Question 45

At which point in the aorta does an abdominal aortic aneurysm typically occur?

Answer 45

Aortic bifurcation

Question 46

What do gonadal arteries arise from and at which vertebral level does this typically occur?

Answer 46

From aorta at L2.

Question 47

What areas do arteries from the abdominal aorta supply?

Answer 47

- urogential system - abdominal wall/diaphragm - gut

Question 48

List the arteries that come off of the abdominal aorta.

Answer 48

- celiac a. - superior mesenteric a. - subcostal a. - left renal a. - right renal a. - left gonadal (testicular or ovarian) - inferior mesenter a. - suprarenal superior middle a. - inferior phrenic

Question 49

Where does the right gonadal (testicular or ovarian) vein drain into?

Answer 49

inferior vena cava

Question 50

Where does the left gonadal (testicular or ovarian) vein drain into?

Answer 50

left renal vein, which drains into the inferior vena cava

Question 51

List the preaortic and paraortic sympathetic ganglia and plexuses found in the abdominal cavity.

Answer 51

- posterior vagal trunk - celiac ganglion and plexus - superior mesenteric ganglion and plexus - sympathetic trunk and ganglion (lumbar portion) - abdominopelvic (greater, lesser, least splanchnic nerves) - renal nerve plexus - aorticorenal ganglion

Question 52

What two pathways does sympathetic innervation of the gut involve?

Answer 52

- splanchnic | - suprarenal

Question 53

Review sympathetic innervation: splanchnic and suprarenal.

Answer 53

Also, draw out the arteries that come off of the abdominal aorta.