Posterior Abdominal Wall Flashcards
What is the primary muscle of respiration?
Diaphragm
What happens to the diaphragm during inspiration?
Descends
What is the sternal origin of the diaphragm?
Xiphoid process
What is the costal origin of the diaphragm?
Internal surfaces of inferior six costal cartilages
What is the lumbar origin of the diaphragm?
Medial and lateral arcuate ligaments and three superior lumbar vertebrae
What is the insertion of the diaphragm?
Central tendon
Where is the medial arcuate ligament?
Body of L1 to TP of L1, arching over psoas major
Where is the lateral arcuate ligament?
TP of L1 to 12th rib, arching over quadratus lumborum
Where is right crus of the diaphragm?
Arises from first three or four lumbar vertebrae and intervertebral disks
Where is left crus of the diaphragm?
Arises from first two or three lumbar vertebrae and intervertebral disks
Which crus of the diaphragm is larger and longer than the other?
Right crus is larger and longer than left crus
What is the caval opening of the diaphragm?
At what spinal level will it occur?
Opening in central tendon for inferior vena cava
Level of T8
What travels in the esophageal hiatus of the diaphragm?
At what spinal level will it occur?
Esophagus, right and left vagal trunks
Level of T10
Which hiatus of the diaphragm forms the right crus?
Esaphageal hiatus
Where is the aortic hiatus?
Which level of the spine is this?
Opening posterior to diaphragm at level of T12
What travels within the aortic hiatus of the diaphragm?
- Aorta
- Thoracic duct
- Azygos veins
- Hemiazygos veins
The right and left crura unite in the midline over the aortic hiatus to form…
median arcuate ligament
Which major arteries will supply the diaphragm?
- Thoracic aorta
- Internal thoracic arteries
- Abdominal aorta
Which branches of the thoracic aorta supply the diaphragm?
Superior phrenic arteries
Which branches of the internal thoracic arteries supply the diaphragm?
- Musculophrenic arteries
- Pericardiophrenic arteries
Which branches of the abdominal aorta supply the diaphragm?
Inferior phrenic arteries
Describe the venous drainage of the diaphragm
Veins mirror arteries and drain to IVC
Which nerve is responsible for both motor and sensory function of the diaphragm?
Phrenic nerve (C3-C5)
Which nerves innervate the diaphragm?
- Phrenic nerve (C3-C5)
- Lower 6-7 intercostal nerves (T5-T11)
- Subcostal nerve (T12)
What type of innervation will lower 6-7 intercostal nerves and subcostal nerve provide the diaphragm?
Sensory
Where is the superior attachment of psoas major?
- Transverse processes of lumbar vertebrae
- Sides of T12-L5 vertebral bodies and IVDs
Where is the inferior attachment of psoas major?
Lesser trochanter, femur
What is the innervation of psoas major?
Anterior rami of lumbar nerves L1-3
What are the primary actions of psoas major?
- Flexes thigh (with iliacus)
- Flexus trunk when sitting (with iliacus)
- Flexes vertebral column laterally
- Balances trunk
What are the superior attachments of iliacus?
- Superior two thirds of iliac fossa
- Ala of sacrum
- Anterior sacroiliac ligaments
What are the inferior attachments of iliacus?
- Lesser trochanter, femur and diaphysis inferior to trochanter
- Psoas major tendon
What is the innervation of iliacus?
Femoral nerve (L2-4)
What is the primary action of iliacus?
Acting with psoas major flexes thigh and stabilizes hip joint
What is iliopsoas?
What is its function?
Integration of inferior fibers of psoas major/minor with iliacus fibers
Major flexor of the thigh and hip stabilizer
What are the superior attachments of quadratus lumborum?
- Medial one half of 12th rib inferior border
- Tips of lumbar TPs
What are the inferior attachments of quadratus lumborum?
- Iliolumbar ligament
- Internal lip of iliac crest
What is the innervation of quadratus lumborum?
- Anterior/ventral rami T12 (subcostal nerve)
- Lumbar plexus (L1-4)
What are the primary actions of quadratus lumborum?
- Extends and laterally flexes vertebral column
- Fixes rib 12 during inspiration
What are the oblique muscles of the posterolateral wall?
Transversus abdominis
What is the spinal level of the celiac trunk?
T12
What is the spinal level of the superior mesenteric artery?
L1
What is the spinal level of renal arteries?
L1
What is the spinal level of gonadal arteries?
L2
What is the spinal level of the inferior mesenteric artery?
L3
What is the spinal level of the aortic bifurcation?
L4
What spinal levels are lumbar arteries?
All lumbar levels
What is the spinal level of the median sacral artery?
L4
Posterior abdominal wall veins drain directly into IVC except…
left gonadal vein and left suprarenal vein
Inferior vena cava begins at ___ (spinal level) to the ___ of the midline
begins at L5 to the right of the midline
Cisterna chyli is formed by convergence of…
- lumbar lymphatic trunk
- intestinal lymph trunks
- descending thoracic trunks
All lymph from the lower half of the body drains to…
cisterna chyli
Where is cisterna chyli?
Anterior to L1-L2 vertebral bodies between IVC and abdominal aorta
Subcostal nerve is the ___ rami of ___
ventral/anterior rami of T12
The subcostal nerve runs along the anterior surface of…
quadratus lumborum
Is the subcostal nerve part of the lumbar plexus?
NO
The lumbar plexus consists of the ___ rami of ___
anterior/ventral rami of L1-L4
Nerves of the lumbar plexus pass through… after roots exit the spine
pass through psoas major after roots exit the spine
Ilioinguinal and iliohypogastric nerves are from what spinal level?
What is their function?
L1
Sensory and motor to anterior abdominal wall muscles
Genitofemoral nerve is from what spinal levels?
What is its function?
L1-2
Sensory to upper medial thigh
Motor to cremaster muscle
Lateral femoral cutaneous nerve is from what spinal levels?
What is its function?
L2-3
Sensory to lateral upper thigh
Femoral nerve is from what spinal levels?
What is its function?
L2-4
Sensory and motor to anterior thigh (quadriceps)
Obturator nerve is from what spinal levels?
What is its function?
L2-4
Sensory and motor to medial thigh (adductors)
Lumbosacral trunk is from what spinal levels?
What is its function?
L4-5
Contribute to sacral plexus
Where is T12 dermatome?
Lateral hip
Where is the dermatome of genitofemoral nerve?
Upper anterior thigh/hip
Where is the L1/ ilioinguinal nerve dermatome?
Inner thigh and genitals
Where is the lateral femoral cutaneous nerve (L2, L3) dermatome?
Lateral thigh
What dermatome is the inner thigh beneath the genitals?
L2-L4 obturator nerve
Where will the femoral nerve’s dermatome be?
Anterior thigh into medial leg
What are the sympathetic nerves from the GI tract to left colic flexure?
- Greater splanchnic nerve
- Lesser splanchnic nerve
- Least splanchnic nerve
What spinal level does the greater splanchnic nerve originate?
T5-9, sometimes T10
What spinal level does the lesser splanchnic nerve originate?
T10-11
What spinal level does the least splanchnic nerve originate?
T12
What is the sympathetic innervation from the left colic flexure to rectum?
Lumbar plexus (L1-3)
Sensory afferent information to sympathetic autonomic nerves refers to…
pain
Sensory afferent information to parasympathetic autonomic nerves refers to…
reflexes
What is the parasympathetic innervation of the GI tract to left colic flexure?
Vagus nerve (CN X) from vagal plexuses
What is the parasympathetic innervation of the left colic flexure to rectum?
Pelvic splanchnic nerves (S2-4)
What is the spinal level of the spleen?
T6-8
What is the spinal level of the stomach, duodenum, liver, gallbladder, and pancreas?
T6-9
What is the spinal level of the jejunum and ileum?
T8-10
What is the spinal level of the suprarenal glands?
T6-L2
What is the spinal level of the kidneys?
T10-L1
What is the spinal level of the cecum, appendix, and ascending colon?
T10
What is the spinal level of the transverse colon?
T11
What is the spinal level of the descending colon?
T12-L2
What is the spinal level of the sigmoid colon and rectum?
S2
Which diaphragm opening is located at the level of T10?
Esophageal hiatus
The greater splanchnic nerve consists predominantly of…
Preganglionic sympathetic fibers from T5-T10