Case 7 Anatomy Flashcards
what is the posterior abdominal wall formed by?
- lumbar vertebrae
- their intervertebral discs
- diaphragm
- psoas muscle
- iliacus muscle
- quadratus lumborum muscles
- thoracolumbar fascia
(large area of connective tissue – roughly diamond-shaped – which comprises the thoracic and lumbar parts of the deep fascia enclosing the intrinsic back muscles)
describe a typical lumbar vertebra
- Has massive, kidney-shaped body
- Has triangular vertebral foramen
- Does not have short, broad transverse processes (long and slender) ?
- Does not have long downward pointing spinous processes (short and broad) ?
- Had medially facing superior articular facets
- Has laterally facing inferiorly articular facets
describe the different movements of the spinal column
- Flexion = bending of the vertebral column in an anterior direction
- Extension = bending of the vertebral column in a posterior direction
- Lateral flexion = bending of the vertebral column to one side
- Lateral extension = returning of the vertebral column to an upright position following lateral flexion
- Rotation = twisting of the vertebral column
- Circumduction = a combination of all movements
which movement is the least extensive in the lumbar region?
rotation
which muscles are involved in flexion of the lumbar spine?
psoas major and rectus abdominis
which muscles are involved in extension of the lumbar spine?
postvertebral muscles
which muscles are involved in lateral flexion of the lumbar spine?
external oblique, internal oblique and postvertebral muscles
describe the diaphragm
- Central tendon
- Caval opening (most anterior)
- Oesophageal hiatus
- Aortic hiatus (most posterior)
- Median arcuate ligament (connects the right and left crura)
- Right crus
- Left crus
- Medial arcuate ligament (tendinous fascia that arches over the psoas major muscle as it passes through the diaphragm – lies between the lateral arcuate ligament and the midline median arcuate ligament)
- Lateral arcuate ligament (arches across the upper part of the quadratus lumborum muscle)
what can the peripheral attachments of the muscular part of the diaphragm be divided into?
three parts: sternal, costal and lumbar
where does the right crus arise from?
the first three or four lumbar vertebrae
which crus is lower?
right, like the right kidney is lower down
where does the left crus arise from?
the first two or three lumbar vertbrae
what is the median arcuate ligament?
fibrous structure that unites the right and left crura
what is the medial arcuate ligament? where does it extend from and to?
- thickening of the fascia (superior part) that covers the psoas major muscle
- extends from the body to the tip of the transverse process of L1
what is the lateral arcuate ligament? where does it extend from and to?
- thickening of the fascia (superior part) that covers the quadratus lumborum muscle
- extends from the transverse process of T12 to the 12th rib
what forms the aortic hiatus?
right and left crura and the median arcuate ligament
at what level is the caval opening?
T8
at what level is the aortic hiatus?
T12
at what level is the oesophageal hiatus?
T10
what goes through the caval opening?
- Right phrenic nerve
* IVC
what goes through the oesophageal hiatus?
- Oesophagus
- Right and left vagi
- Oesophageal branches of left gastric artery
- Lymphatics from oesophagus
what goes through the aortic hiatus?
- Thoracic duct
- Aorta
- Azygos vein
what are the muscles of the posterior abdominal wall?
- Psoas major
- Iliacus
- Quadratus lumborum
the tendons of the psoas major and iliacus muscles unit and insert onto where?
lesser trochanter of the femur
where does the psoas major muscle arise from?
bodies and transverse processes of T12-L5 vertebra and the intervening discs
what do the psoas major and iliacus muscles combine to form and what does this do?
- iliopsoas muscle
- main flexor of the hip joint
what does the quadratus lumborum do during inspiration?
fixes the 12th rib
where does the iliacus originate from?
iliac fossa (upper 2/3 of iliac fossa, internal lip of iliac crest, lateral aspect of sacrum, ventral sacroiliac ligament and lower portion of iliolumbar ligament)
what is the iliacus innervated by?
femoral nerve
what is psoas major innervated by?
(psoas major is innervation by anterior rami of L1-3)
what is the internal aspect of the abdominal wall covered with? where does this lie?
fascia which lies between the parietal peritoneum and the muscle
what are the psoas and iliacus covered by?
endoabdominal fascia
what is the endoabdominal fascia continuous with where?
- diaphragmatic fascia superiorly
- transversalis fascia laterally
what is the quadratus lumborum covered by?
thoracolumbar fascia
where do the main vessels of the posterior abdominal wall lie?
anterior to the bodies of the lumbar vertebrae
where does the abdominal aorta begin and end? what levels?
- Begins at the aortic hiatus at the level of T12 and ends by bifurcating into the right and left common iliac arteries
- Bifurcation of the aorta occurs at L4
what are the posterior relations of the abdominal aorta?
- The abdominal aorta lies in front of the bodies of T12-L4
* The lumbar veins cross behind the aorta on route to the vena cava
what are the right lateral relations of the abdominal aorta?
- Inferior vena cava
- Azygos vein
- Cisterna chyli
- Right coeliac ganglion
- Right crus of diaphragm
- Thoracic duct
what are the left lateral relations of the abdominal aorta?
- Left crus of diaphragm
- Left coeliac ganglion
- Left sympathetic chain (not on right side because that’s on the right of the IVC)