Abdominal Wall 2 Flashcards
What is the origin and insertion of quadratus lumborium?
Origin:
- inferior border of 12th rib
- transverse processes of L1-4 vertebrae
Insertion:
- iliolumbar ligament
- iliac crest
What is the action and nerve supply of quadratus lumborium?
Actions:
- pulls down 12th rib to help descent of diaphragm during inspiration
- lateral flexion of vertebral column
Nerve supply: T12-L4
What muscle fascia constitutes the lateral arcuate ligament?
quadratus lumborium
What is the origin and insertion of psoas major?
Origin:
- transverse processes of lumbar vertebrae
- bodies of T12-L4 and IV disks
Insertion:
- lesser trochanter
What is the action and nerve supply of psoas major?
Actions:
- flexion of thigh
- flexion of trunk
- lateral flexion of vertebral column
Nerve supply: L1-3
What is the origin, insertion and nerve supply of psoas minor?
- origin: bodies of T12-L1
- insertion: pectineal line and iliopectineal line
- nerve supply: L1
What is the origin and insertion of iliacus?
Origin:
- iliac fossa
- iliac crest
- anterior sacroiliac ligament
Insertion: lesser trochanter
What is the action and nerve supply of iliacus?
- action: flexion of thigh
- nerve supply: femoral L2-4
What divides the msucular and vascular compartments at the groin and what is contained in them?
- divided by femoral sheath
- muscular compartment: transmits psoas major and iliacus muscles, and femoral nerve
- vascular compartment: transmits femoral vessels
What are the boundaries of the femoral canal?
- anterior: inguinal ligament
- medial: lacunar ligament
- posterior: pectineus or pectineal ligament
- lateral: femoral vein
Discuss femoral hernias
- femoral ring is a weak area often associated with abnormal protrusion of abdominal organs into femoral canal
- more common in females
- pubic tubercle can be used to distinguish whether hernia is femoral or inguinal
Which of the spinal roots are motor and sensory?
- anterior: motor
- posterior: sensory
What spinal nerves supply the muscles of the abdominal wall?
- T7-12
- L1
- L1 contributes to iliohypogastric and ilioinguinal nerves
- nerves pass between internal oblique and transversus abdominis to enter rectus sheath
What supplies the epigastrium and what pain is referred here?
- T6-7
- stomach and oesophagus
What supplies the umbilicus and what pain is referred here?
- T10
- appendix, gonad, and small intestine
What supplies the pubic region and what pain is referred here?
- T12
- lower colon, bladder and uterus
Describe the clinical anatomy of herpes zoster
- varicella zoster virus can be reactivated and cause shingles
- a rash can form along the course of a dermatome
- remains painful until rash has gone
Describe the lumbar plexus
- iliohypogastric (L1)
- ilioinguinal (L1)
- geniofemoral (L1,2)
- lateral femoral cutaneous (L2,3)
- Obturator (L2,3,4)
- femoral (L2,3,4)
- to lumbosacral trunk
Describe the arterial supply of the posterior abdominal wall
- intercostal arteries
- lumbar arteries (from abdo aorta)
- superior epigastric arteries (from ITA) - descends behind rectus abdominis in rectus sheath
- inferior epigastric arteries (from external iliac) - on medial side of deep inguinal ring
- superficial epigastric arteries (from femoral)
- superficial circumflex iliac arteries (from femoral)
- deep circumflex arteries (from external iliac)- laterally parallel to inguinal ligament
Describe the venous drainage of the posterior abdominal wall
- accompany arteries to all eventually drain to:
- femoral and external iliac veins inferiorly
- internal thoracic and axillary veins superiorly
- superficial epigastric and superficial circumflex iliac veins can drain to proximal end of saphenous vein
- para-umbilical veins connect system through umbilicus to portal veins in liver
What is caput medusae?
a network of dilated veins surrounding the umbilicus.
What is the lymphatic drainage of the superficial posterior abdominal wall?
Anterior:
- above umbilicus to anterior axillary nodes
- below umbilicus to superficial inguinal nodes
Posterior:
- above iliac crests to posterior axillary nodes
- below iliac crests to superficial inguinal nodes
What is the lymphatic drainage of the deep abdominal wall?
- drained by vessels alongside epigastric vessels
- superiorly to parasternal to mediastinal nodes
- inferiorly to external iliac to para-aortic nodes
How can a psoas abscess occur?
- psoas muscle and sheath arise from lumbar vertebrae but also IV disks between vertebrae
- infection can arise and spread into muscle sheath within muscle and sheath and appear below inguinal ligament as mass
