Posterior Abdominal Wall

Question 1

Bones

Answer 1

Ribs 11 & 12
Lumbar vertebrae
Sacrum
Illia

Question 2

Diaphragm

Answer 2

Attached to the costal margin and vertebrae
Combination of skeletal muscle and the central tendon
Contains 3 hiatuses - T8, T10 and T12 (I ate 10 eggs at 12)
Passage for the IVC, oesophagus and aorta
Arteries and veins: superior and inferior phrenic vessels
Nerves: Phrenic (C3-5) motor; Intercostal (T5-11) & subcostal (T12) – sensory

Question 3

Quadratus Lumborum

Answer 3

Lies posterior to the kidneys
Extends from iliac crest to Rib 12 (Also attached laterally to the transversus abdominis muscle)
Provide abdominal stability and causes lateral flexion
Arteries & veins – lumbar vessels
Nerves – lumbar (T12-L4)

Question 4

Psoas and Iliacus

Answer 4

Psoas muscles originate at lumbar vertebrae
Iliacus originates in the iliac fossa
Psoas maj and min converge inferiorly and can be known as iliopsoas
All insert at the lesser trochanter femur and function as hip flexors
Arteries and veins: lumbar vessels
Nerves: femoral (L2-L4)

Question 5

Abdominal Aorta Branches

Answer 5

3 categories:
Midline - Coeliac (T12), superior mesenteric (L1) and inferior mesenteric (L3)
Parietal - Lumbar
Visceral - Renal and gonadal (L2)
Bifurcates into the common iliac vessels at L4/5
Clinical considerations of abdominal aorta: abdominal aortic aneurysm (AAA)

Question 6

Abdominal Innervation

Answer 6

Somatic: voluntary (skeletal muscle) - abdominal wall, intercostal, vertebral and intervertebral musclulature; sensation - skin
Somatic innervation: lumbar plexus (right) and sacral plexus (left)
Autonomic: unconscious control - Blood vessels, sweat glands, abdominal organs
Autonomic Innervation: Unconscious control of organs, smooth muscle, sweat glands; split into sympathetic and parasympathetic divisions; splanchnic nerves are heavily involved in innervation of organs - namely for the adrenal glands and kidneys

Question 7

Splanchnic Nerves & prevertebral ganglia

Answer 7

Classification of purely autonomic nerves
These nerves synapse to postganglionic neurones at the specific central ganglia – the prevertebral ganglia
Prevertebral Ganglia:
- Located anterior to the vertebral column and aorta
- Greater, lesser and least splanchnic nerves synapse at the coeliac and aorticorenal ganglion to innervate the suprarenal glands

Question 8

Abdominal Pain

Answer 8

Somatic: Well localised, sharp or stabbing; Felt in skin, muscle, fascia, and parietal peritoneum
Visceral: Poorly localised, dull ache, or throbbing; Caused by stretching, ischaemia or chemical damage
Referred: Felt elsewhere than the affected structure
- Dermatomes: Stomach: felt in skin of dermatomes T5-9, Appendix: T10, Gallbladder: T7-9, With parietal peritoneum involvement: C3, 4