the posterior abdominal wall

Question 1

describe the bones of the posterior abdominal wall? 4

Answer 1

• ribs 11 and 12
• lumbar vertebrae
• sacrum
• ilia

Question 2

describe the musculature of the posterior abdominal wall? 4

Answer 2

• diaphragm
• quadratus lumborum
• psoas major
• iliacus

Question 3

describe the diaphragm? 5

Answer 3

• Attached to the costal margin and vertebrae
• Combination of skeletal muscle and the central tendon
• Contains 3 hiatuses:
• T8, T10 & T12
• Passage for the IVC, oesophagus and aorta

Question 4

describe there neuromuscular supply of the diaphragm? 3

Answer 4

• Arteries and veins
• Superior and inferior phrenic vessels
• .
• Nerves:
• Phrenic (C3-5)- motor
• Intercostal (T5-11) and subcostal (T12)- sensory

Question 5

describe the quadratus lumborum? 4

Answer 5

• 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

Question 6

describe the neuromuscular supply of the quadratus lumborum? 2

Answer 6

• Arteries and veins- lumbar vessels
• .
• Nerves:
• Lumbar (T12-L4)

Question 7

describe the psoas and iliacus? 4

Answer 7

• Psoas muscles originate at the lumbar vertebrae
• Iliacus originates in the Iliac fossa
• Psoas major and minor coverage inferiorly and can be known as iliopsoas
• At insert at the lesser trochanter femur and function as hip flexors

Question 8

describe the neuromuscular supply to the psoas and iliacus? 2

Answer 8

• Arteries and veins: lumber vessels

- Nerves: femoral (L2, L4)

Question 9

describe the major vasculature in the posterior abdominal wall? 3

Answer 9

• Aorta- enter abdomen at T12
• Inferior vena Cava- enter abdomen at T8
• Provide and drain blood from the abdomen, pelvis and lower limbs

Question 10

describe the abdominal aorta branches? 4

Answer 10

• 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

Question 11

describe a clinical consideration of the abdominal aorta?

Answer 11

• Abdominal aortic aneurysm (AAA) 5.5cm is considered at significant risk of rupture

Question 12

describe somatic abdominal innervation? 3

Answer 12

• Voluntary movement (skeletal muscle) = Abdominal wall, intercostal, vertebral and intervertebral musculature
• Sensation= skin
• Provided by nerve plexuses: lumbar plexus on the right and sacral plexus on the left

Question 13

describe autonomic abdominal innervation? 3

Answer 13

• Unconscious control= blood vessels, sweat glands, abdominal organs (digestive tract to control peristalsis)
• Split into sympathetic and parasympathetic divisions
• Splanchnic nerves are heavily involved in innervation of organs- namely for the adrenal glands and kidneys

Question 14

describe the splanchnic nerves in the posterior abdominal wall? 3

Answer 14

• A classification of purely autonomic nerves
• These nerves synapse to postganglionic neurones at specific central ganglia- the paravertebral ganglia
• The least supplies the kidneys

Question 15

describe the prevertebral ganglia in the posterior abdominal wall? 2

Answer 15

• Located anterior to the vertebral column and aorta
• Greater, lesser and least splanchnic nerves synapse at the coeliac and aorticoreneal ganglion to innervate the suprarenal glands

Question 16

describe abdominal pain? 3

Answer 16

• 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

Question 17

describe abdominal dermatomes? 3

Answer 17

• Stomach: felt in the skin of dermatomes T5-9
• Appendix: T10 (umbilicus)
• Gallbladder: T7-9 with parietal peritoneum involvement: C3,4