Posterior Abdominal Wall

Question 1

Psoas Major

Answer 1

O:
Transverse processes of lumbar vertebrae; sides of bodies of T12–S1 vertebrae and intervening IV discs

In:
By a strong tendon to lesser trochanter of femur

Inn:
Lumbar plexus via anterior branches of nerves L2–L4

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

Question 2

Psoas Minor

Answer 2

O:
Sides of T12 and L1 vertebral bodies and disc between them

In:
Pectin Pubic, Iliopubic ramus, laterally to iliac fascia

Inn:
Branch of L1

Action:
Flexes trunk weakly

Question 3

Iliacus

Answer 3

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

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

Inn:
Femoral nerve (L2–L4)

Action:
Flexes thigh and stabilizes hip joint; acts with psoas major

Question 4

Quadratus Lumborum

Answer 4

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

In:
Iliolumbar ligament and internal lip of iliac crest

Inn:
Anterior branches of T12 and L1–L4 nerves

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

Question 5

Spermatic Cord

Answer 5

• Contains structures running to and from the testis.

- Suspends the testis in the scrotum.

Question 6

Spermatic Cord Contents

Answer 6

• Ductus Deferens
• Testicular Artery (L2)
• Artery of Ductus Deferens
• Cremasteric Artery
• Pampiniform venous plexus
• Sympathetic nerve fibers
• Genital branch of genitofemoral nerve
• Lymphatic vessels
• Vestige of the processus vaginalis