*Anatomy: Posterior Abdominal Wall Flashcards
Identify the main posterior abdominal wall muscles.
Quadratus lumborum Psoas Major Psoas Minor Diaphragm Iliacus
QUADRATUS LUMBORUM
- Origin
- Insertion
- Innervation
- Action
QUADRATUS LUMBORUM
- Origin: Inferior border of rib 12, tranverse processes of lumbar vertebrae
- Insertion: Iliolumbar ligament, iliac crest
- Innervation: T12-L4
- Action: Fixes rib 12 during inspiration + lateral flexion (and extension) of the vertebral column
PSOAS MAJOR
- Origin
- Insertion
- Innervation
- Action
PSOAS MAJOR
- Origin: Tranverse processes of lumbar vertebrae, bodies of T12-L4 and IV discs
- Insertion: Losser tronchanter
- Innervation: L1-3
- Action: Flexion of the thigh (with iliacus), flexion of the trunk (with iliacus), lateral flexion of the vertebral column
PSOAS MINOR
- Origin
- Insertion
- Innervation
- Action
PSOAS MINOR
- Origin: Bodies of T12-L1
- Insertion: Pectineal line and iliopectineal eminence
- Innervation: L1
- Action: weak trunk flexor
ILIACUS
- Origin
- Insertion
- Innervation
- Action
ILIACUS
- Origin: Iliac fossa, iliac crest, anterior sacroiliac ligament
- Insertion: Lesser trochanter
- Innervation: Femoral nerve
- Action: Flexion of the thigh (with psoas major)
Describe the muscular and vascular compartments in the posterior abdominal wall.
- The space between the inguinal ligament and the hip bone is divided by femoral sheath into muscular and vascular compartments.
- Muscular compartment transmits psoas major and iliacus muscles as well as femoral nerve.
- Vascular compartment transmits femoral vessels.
What is the femoral sheath ?
Extension of transversalis fascia
State the location of the femoral ring. What is the femoral ring ?
The femoral ring is medial to the vascular compartment.
Femoral ring is the opening of the femoral canal.
Identify the boundaries of the femoral canal.
Inguinal ligament (A) Lacunar ligament (M) Pectineus or pectineal ligament (P) Femoral vein (L)
What closes the femoral ring ?
Extra-peritoneal tissue closes the femoral canal.
Explain how femoral hernias occur.
Femoral ring is a weakened area and often associated with abnormal protrusion of the ab organs into the femoral canal.
Explain epidemiology of femoral hernias.
Which of femoral or inguinal hernias is more prone to strangulation ?
Women much more susceptible
Femoral hernias more prone to strangulation than inguinal hernias
How may inguinal and femoral hernias be distinguished ?
Use pubic tubercle as landmark
Explain the general principles of spinal nerves.
Spinal nerves arise from segments of the spinal cord and emerge as dorsal (posterior) sensory roots and ventral (anterior) motor roots.
The sensory and motor roots combine to form a mixed spinal nerve that passes through an IV foramen and divides into a dorsal and a ventral ramus.
Define dermatome. How is each spinal nerve named ?
Region/area of skin supplied by specific spinal nerve.
Each spinal nerve is named in relation to the IV foramen from which it emerges.