The posterior abdominal wall Flashcards
Which bones make up the posterior abdominal wall?
- Ribs (11 and 12)
- Lumbar vertebrae
- Sacrum
- Ilia
What muscles make up the posterior abdominal wall?
- Diaphragm
- Quadratus Lumborum
- Psoas Major (& Minor)
- Iliacus
Where is the diaphragm attached to?
Attached to the costal margin and vertebrae
What is the diaphragm made up of?
Combination of skeletal muscle and the central tendon
Contains 3 hiatuses
- T8, T10 & T12
- Passage for the IVC, oesophagus and aorta
What is the neurovascular supply to the diaphragm?
Neurovascular supply:
- Arteries & Veins - Superior and inferior phrenic vessels
- Nerves
- Phrenic (C3-5) - Motor
Intercostal (T5-11) & Subcostal (T12) - Sensory
Which structure passes through the diaphragmatic hiatus at T8?
A.Aorta
B.IVC
Oesophagus
B.IVC
Where is quadratus lumborum?
Lies posterior to the kidneys
Extends from iliac crest to Rib 12
-Also attached laterally to the transversus abdominis muscle
What is the role of quadratus lumborum?
Provide abdominal stability and causes lateral flexion
What is the neurovascular supply to quadratus lumborum?
Neurovascular supply:
- Arteries & Veins - Lumbar vessels
- Nerves - Lumbar (T12-L4)
Where is psoas major?
Psoas muscles originate at the 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
What is the neurovascular supply of the psoas and iliacus muscle?
Neurovascular supply:
- Arteries & Veins - lumbar vessels
- Nerves - Femoral (L2 - L4)
What major vasculature passes through the posterior abdominal wall?
Aorta - Enters abdomen at T12
Inferior Vena Cava - Enters abdomen at T8
Provide and drain blood from the abdomen, pelvis and lower limbs.
What are the 3 types of abdominal aorta branches?
- Midline - Coeliac (T12), sup. mesenteric (L1) and inf. mesenteric (L3)
- Parietal - Lumbar
- Visceral - Renal and gonadal (L2)
Where does the abdominal aorta bifurcate?
Bifurcates into the common iliac vessels at L4/5
Whats the diagnosis?
Abdominal Aortic Aneurysm (AAA)
Whats the diagnosis?
Abdominal Aortic Aneurysm (AAA)
Above what size is an abdominal aortic aneurysm considered at significant risk of rupture?
A.1cm
B.3.5cm
C.5.5cm
D.8cm
12.5cm
C.5.5cm
What is the somatic innervation of the abdomen?
- Voluntary movement (skeletal muscle)
- Abdominal wall, intercostal, vertebral and intervertebral musculature
- Sensation
- Skin
What is the abdominal somatic innervation provided by?
Provided by nerve plexuses:
- Lumbar plexus (right)
- Sacral plexus (left)
What is the autonomic innervation of the abdomen?
- Unconscious control
- Blood vessels, sweat glands
- Abdominal organs (digestive tract to control peristalsis etc.)
What does autonomic innervation control?
Unconscious control of:
- Organs
- Smooth muscle
- Sweat glands
Which nerves are important in autonomic control of organs?
Splanchnic nerves are heavily involved in innervation of organs
-Namely for the adrenal glands and kidneys
What are splanchnic nerves?
A classification of purely autonomic nerves
These nerves synapse to postganglionic neurones at specific central ganglia - the prevertebral ganglia.
What are prevertebral ganglia?
Located anterior to the vertebral column and aorta
“Pre-” meaning before
Greater, lesser and least splanchnic nerves synapse at the coeliac and aorticorenal ganglion to innervate the suprarenal glands.
Which splanchnic nerve innervates the kidneys?
A.Greater
B.Lesser
C.Least
D.Pelvic
Thoracic
C.Least
What are the 3 catagories of abdominal pain?
- 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
Where is referred pain from the stomach, appendix, gallbladder and parietal peritoneum felt?
- Stomach: felt in skin of dermatomes T5-9
- Appendix: T10 (umbilicus)
- Gallbladder: T7-9
- With parietal peritoneum involvement: C3,4
Where would you feel referred pain from the diaphragm?
A.Forearm
B.Pectoral region
C.Perineum
D.Scalp
E.Shoulder
E.Shoulder
