Posterior Abdominal Wall

Question 0

What is the origin of the psoas major?

Answer 0

Transverse processes of lumbar vertebrae; sides of bodies of T12-S1 vertebrae and intervening IV discs

Question 1

What are the muscles of the posterior abdominal wall?

Answer 1

Psoas major, iliacus, quadratus lumborum

Question 2

Where does the psoas major insert?

Answer 2

By a strong tendon to the lesser trochanter of the femur

Question 3

What is the innervation of the psoas major?

Answer 3

Lumbar plexus via anterior branches of nerves L2-L4

Question 4

What action does the psoas major perform?

Answer 4

Acting inferiorly with iliacus it flexes the thigh and acting superiorly it flexes vertebral column laterally to balance the trunk, and when sitting acts inferiorly with iliacus to flex trunk

Question 5

What is the origin of the iliacus?

Answer 5

Superior two thirds of iliac fossa, ala of sacrum, and anterior sacro-iliac ligaments

Question 6

Where does the ilacus insert?

Answer 6

Lesser trochanter of femur and shaft inferior to it and psoas major tendon

Question 7

What is the innervation of the iliacus?

Answer 7

Femoral nerve (L2-L4)

Question 8

What is the action of the iliacus?

Answer 8

Flexes thigh and stabilizes hip joints; acts with psoas major

Question 9

What is the origin of the quadratus lumborum?

Answer 9

Medial half of inferior border of 12th rib and tips of lumbar transverse processes

Question 10

Where does the quadratus lumborum insert?

Answer 10

Iliolumbar ligament and internal lip of iliac crest

Question 11

What is the innervation of the quadratus lumborum?

Answer 11

Anterior branches of T12 and L1-L4 nerves

Question 12

What action does the quadratus lumborum perform?

Answer 12

Extends and laterally flexes vertebral column; fixes 12th rib during inspiration

Question 13

What is the lumbar plexus composed of?

Answer 13

Anterior rami of L1-L4 nerves

Question 14

What nerves make up branches of the lumbar plexus?

Answer 14

Obturator nerve, femoral nerve, lumbosacral trunk, ilio-inguinal and iliohypogastric nerves, genitofemoral nerve, and lateral cutaneous nerve of the thigh

Question 15

What is the origin of the psoas minor?

Answer 15

Lateral aspect of vertebral body of T12 and L1

Question 16

Where does the psoas minor insert?

Answer 16

Pectin pubis

Question 17

What is the innervation of the psoas minor?

Answer 17

Anterior rami of L1

Question 18

What action does the psoas minor perform?

Answer 18

Weak flexor of trunk

Question 19

What is the origin of the obturator nerve?

Answer 19

Medial border of psoas major

Question 20

What is the course of the obturator nerve?

Answer 20

Passes through the pelvis to the medial thigh

Question 21

What is the distribution of the obturator nerve?

Answer 21

Adductor muscles

Question 22

What is the segmental innervation of the obturator nerve?

Answer 22

L2-L4

Question 23

What is the origin of the femoral nerve?

Answer 23

Lateral border of psoas major and innervates the iliacus

Question 24

What is the course of the femoral nerve?

Answer 24

Passes deep to the inguinal ligament to the anterior thigh

Question 25

What is the distribution of the femoral nerve?

Answer 25

Flexors of the hip and extensors of the knee

Question 26

What is the segmental innervation of the femoral nerve?

Answer 26

L2-L4

Question 27

What is the course of the lumbosacral trunk?

Answer 27

Passes over the ala of the sacrum and descends into the pelvis to participate in the formation of the sacral plexus along with anterior rami of S1-S4 nerves

Question 28

What is the segmental innervation of the lumbosacral trunk?

Answer 28

L4, L5

Question 29

What is the origin of the ilioinguinal nerve?

Answer 29

Inferior terminal branch of anterior ramus of L1 spinal nerve

Question 30

What is the course of the ilio-inguinal nerve?

Answer 30

Passes between second and third layers of abdominal muscles, then transverses into inguinal canal

Question 31

What is the distribution of the ilio-inguinal nerve?

Answer 31

Skin of scrotum or labium majus, mons pubis, and adjacent medial aspect of thigh; most of inferior internal oblique and transversus abdominis

Question 32

What is the segmental innervation of the ilio-inguinal nerve?

Answer 32

L1

Question 33

What is the origin of the iliohypogastric nerve?

Answer 33

Superior terminal branch of anterior ramus of L1 spinal nerve

Question 34

What is the course of the iliohypogastric nerve?

Answer 34

Pierces transverse abdominis muscle

Question 35

What is the distribution of the iliohypogastric nerve?

Answer 35

Skin overlying iliac crest, upper inguinal and hypogastric regions; internal oblique and transversus abdominis

Question 36

What is the segmental innervation of the iliohypogastric nerve?

Answer 36

L1

Question 37

What is the origin of the subcostal nerve?

Answer 37

Anterior ramus of T12 spinal nerve

Question 38

What is the course of the subcostal nerve?

Answer 38

Runs along inferior border of 12th rib, then onto subumbilical abdominal wall

Question 39

What is the distribution of the subcostal nerve?

Answer 39

Muscles of anterolateral abdominal wall and overlying skin midway between level of umbilicus and iliac crest, inguinal ligament, and pubic crest inferiorly

Question 40

What is the segmental innervation of the subcostal nerve?

Answer 40

T12

Question 41

What is the crura of the diaphragm?

Answer 41

Musculotendinous bundles that arise from the anterior surfaces of the bodies of the superior three lumbar vertebrae, the anterior longitudinal ligament, and IV discs

Question 42

Which crus is bigger?

Answer 42

The right crus is larger and longer than the left and the two are united by the median arcuate ligament

Question 43

What are the three large apetures of the diaphragm?

Answer 43

Caval opening, esophageal hiatus, and aortic hiatus

Question 44

What runs through the apetures of the diaphragm?

Answer 44

IVC, esophagus, and aorta

Question 45

Where does the caval opening lie?

Answer 45

Level of T8 vertebra or T8/T9 IV disc

Question 46

Where does the esophageal hiatus lie?

Answer 46

Level of T10 vertebra

Question 47

Where does the aortic hiatus lei?

Answer 47

Level of T12 vertebra

Question 48

What are the main structures in the inguinal canal?

Answer 48

Spermatic cords conveying the ductus deferens in males and round ligament of the uterus in females

Question 49

What is the significance of the deep (internal) ring?

Answer 49

It is the internal entrance to the inguinal canal

Question 50

What is the significance of the superficial (external) ring?

Answer 50

It is the exit from the inguinal canal that is a slit like opening in the aponeurosis of the external oblique

Question 51

What are the margins of the superficial (external) ring?

Answer 51

Lateral and medial crus

Question 52

What provides the entire motor supply to the diaphragm?

Answer 52

Right and left phrenic nerves which arise from anterior rami of C3-C5 spinal segments

Question 53

What direction does the diaphragm move during inspiration?

Answer 53

It descends

Question 54

What are the tributaries of the inferior vena cava?

Answer 54

Hepatic vein, right and left renal veins, and right gonadal vein