Posterior Abdominal Wall and Diaphragm

Question 1

What long fusiform muscle lies lateral to the lumbar vertebral column?

Answer 1

Psoas major

Question 2

Where does the psoas major originate?

Answer 2

originates on the lumbar vertebral bodies

then tapers at L5 to join the ilacus muscle and form the iliopsoas

Question 3

Where does the combined ilipsoas muscle insert?

Answer 3

it passes beneath the inguinal ligament to insert on the lesser trocanter of the femur

Question 4

What does the psoas major do? WHat does the iliopsoas do?

Answer 4

psoas major flexes the vertebral column

the iliopsoas also flexes the hip joint

Question 5

Where does the psoas minor muscle lie in relation to the psoas major?

Answer 5

it;s a slender muscle that lies just anterior to it (only present in 50% of the population)

Question 6

Where does the iliacus originate?

Answer 6

from the superior part of the iliac fossa

Question 7

Why is the iliopsoas muscle important clinically?

Answer 7

If the ureters, kidneys, cecum, appendix, sigmoid colon, pancreas, lumbar LNs or nerves on the posterior abdominal wall are diseased, movement of the iliopsoas muscle may be accompanied by pain

Question 8

What is the thick muscle sheet originating on the iliac crest and 2-4 lumbar transverse processes and inserting on the 12th rib?

Answer 8

the quadratus lumborum

Question 9

What does the quadratus lumborum do?

Answer 9

fixes the 12th rib in relation to the pelvis.Acting alone, one side flexes the trunk, but together both muscle extend the trunk

Question 10

What is the third and innermost of the 3 flat muscles of the anterior abdominal wall?

Answer 10

transverse abdominis

Question 11

IN general, the posterior abdominal muscles are covered by deep fascia named according to the muscle. But what’s the general term for all of it?

Answer 11

transversalis fascia

Question 12

Where is the muscular portion of the diaphragm located?

Answer 12

all around the periphery

Question 13

What are the 3 portions of the muscular portion?

Answer 13

Sternal portion (from xiphoid process and adjacent aponeurosis of the transversus abdominis)

Costal portion (cartilage and bony surface of ribs 7-12_

Lumbar portion (arising from vertebral column)

Question 14

What divides the sternal and costal portions?

Answer 14

they’re separated by small gaps called the sternocostal triangles through which the superior epigastric vessels continue into the abdomen

Question 15

What are the two parts of the lumbar portion?

Answer 15

the right and left crura

Question 16

Which crus is longer and better developed?

Answer 16

the right crus

Question 17

The right crus contributes to the muscular porion of the dipahragm between what two structures?

Answer 17

between the aortic and esophageal hiatuses

Question 18

What does the right crus form in relation to the duodenum?

Answer 18

the ligament of Treitz (suspensory ligament or muscle)

Question 19

WHere do the right and left crura arise form?

Answer 19

right: vertebral bodies of L1-L3

left from L1-L2

Question 20

What unites the two crura? What does this form?

Answer 20

united by the median arcuate ligament, which forms the aortic hiatus

Question 21

What are the three arcuate (lumbocostal) ligaments?

Answer 21

the median arcuate ligament
the medial arcuate ligaments
lateral arcuate ligaments

Question 22

What do the medial arcuate ligaments arch over?

Answer 22

the psoas major muscle

Question 23

What do the lateral arcuate ligaments arch over?

Answer 23

the superior part of the quadratus lumborum

Question 24

All muscle fibers of the diaphragm converge and insert on what?

Answer 24

the central tendon - it’s a strong aponeurosis with interlacing tendinous fibers

NO bony attachments

Question 25

What are the 4 hiatuses in the diaphragm?

Answer 25

1. hiatus for the IVC 2. Esophageal hiaus 3. Aortic hiatus 4. minor openins for splanchnic nerves in the R and L crus and for sueprior epigastric vessels at the sternocostal triangles

Question 26

At what level is the hiatus for the IVC?

Answer 26

T8

Question 27

What passes through the IVC hiatus besides the IVC?

Answer 27

branches of the right phrenic nerve

Question 28

At what level is the esophageal hiatus?

Answer 28

slightly to the left of midline at T10

Question 29

What passes through the esophageal hiatus besides the esophagus?

Answer 29

vagal trunks (anterior and posterior) anastomotic vessels connecting the vessels of the trhoacic esophagus with those of the stomach (left gastric branches)

Question 30

At what level is the aortic hiatus?

Answer 30

it's immediately anterior to the vertebral column at the level of T12

Question 31

What passes thorugh the aortic hiatus besides the aorta?

Answer 31

thoracic duct elements of the azygos and hemiazygos system of veins

Question 32

What superior arteries supply the diaphragm from above (3 sets)...

Answer 32

superior phrenic arteries pericardiacophrenic arteries musculophrenic arteries

Question 33

Where do the superior phrenic arteries branch from? WHat part do they supply?

Answer 33

direct branches off the trhoacic aorta supply posterior aspect

Question 34

Where do the pericardiacophrenic arteries come from and what part do they supply?

Answer 34

they're branches of the internal thoracic arteries accompanying the phrenic nergves supply the central area

Question 35

Where do the musculophrenic arteries come from? What part do they supply?

Answer 35

one of the terminal branches of the internal thoracic arteries supply the periphery of the diaphragm

Question 36

What set of arteries supplies the diaphragm from below?

Answer 36

inferior phrenic arteries - this is hte major source of blood to the diaphragm.

Question 37

Where do the inferior phrenic arteries come from?

Answer 37

branches of the abdominal aorta just inferior to the hiatus

Question 38

What's the chief route of venous drainage from the diaphragm?

Answer 38

parallels the arteries, but mostly follows inferior phrenic veins... L inferior phrenic vein drains to left suprarenal then left renal

Question 39

What supplies motor innervation to the diaphragm?

Answer 39

phrenic nerves C3, 4, 5 keeps the diaphragm alive (somatic efferents)

Question 40

Somatic afferents from the dipahragm are derived from what two sources?

Answer 40

phrenic nerve (central area) and intercostal nerves (peripheral inch)

Question 41

When the peritoneum covering the diaphragm is irritated, pain is referred where? Why?

Answer 41

to the shoulder region this is the area of the periteonum supplied by the phrenic nerve, the same segments providing innervation to the skin of the shoulder region (via supraclavicular nerves C3 and C4 from cervical plexus)

Question 42

What if it's only the periteoneum that covers the peripheral part of the diaphragm supplied by intercostal nerves?

Answer 42

it will be referred to the thoracic wall

Question 43

What are hiccups?

Answer 43

due to irritation of afferent or efferent nerve endings of the phrenic or of medullary centers in the brainstem causing involuntary spasms of the diaphragm and glottis

Question 44

What are the two main actions of the diaphragm?

Answer 44

it's the chief muscle of inspiration also important in abdominal straining

Question 45

Where is the cisternal chyli located?

Answer 45

between the aorta and the right crus of the diaphragm

Question 46

What are the three main tributaries of the cisternal chyli?

Answer 46

right and left lumbar lymph trunks and a single intestinal lymph trunk

Question 47

What do the lumbar lymph trunks drain?

Answer 47

they drain the lumbar LNs alongside the lumbar vertebrae which in turn receive lymph from the lower extremity via external and common iliac chains of nodes, the pelvis, kidney, suprarenal glands and body wall

Question 48

What does the intestinal lymph trunk drain?

Answer 48

receives lymph from intestine, stomach, spleen, pancreas and liver

Question 49

What branches of the lumbar plexus supply the muscles and skin of the back?

Answer 49

the dorsal rami of L1-L5 lumbar nerves

Question 50

What two plexi are formed by the ventral rami after they extend into the posterior aspect of the psoas muscle?

Answer 50

L1-3 and upper half of L4 form the lumbar plexus lower half of L4 and L5 form the lubosacral trunk, which joins the sacral plexus in the pelvis

Question 51

What are the 7 branches of the lumbar plexus?

Answer 51

1. ilioinguinal 2. iliohypogastric 3. genitofemoral (femoral and genital branches) 4. lateral femoral cutaneous nerve 5. obturator nerve 6. femoral nerve 7. lumbosacral trunk

Question 52

WHere does the femoral branch of the genitofemoral nerve pass?

Answer 52

passes beneath the inbuinal ligament within the femoral sheath to supply the skin over the femoral truangle

Question 53

Where does the genital branch of the genitofemoral nerve pass?

Answer 53

runs to the deep inguinal ring and traverses the inguinal canal to supply the cremaster muscle

Question 54

What does the lateral femoral cutaneous nerve supply?

Answer 54

skin over lateral and anterior thigh