19. Posterior Abdomen Flashcards
What is the function of the posterior abdominal wall?
To support vessels and organs
Identify the various parts of the posterior abdominal wall and their functions.
- orange: DIAPHRAGM = superior border of the posterior abdominal wall = inferior border of thorax
- red: TRANSVERSUS ABDOMINIS: used in force exhalation to increase abdominal pressure, pushes intestine upward into diaphragm to squeeze air out
- blue: QUADRATUS LUMBORUM: bilaterally: extension of spine, unilaterally: ipsilateral flexion of spine
- purple: PSOAS MINOR: spine flexion (not much contribution)
- green: PSOAS MAJOR: hip flexor
- yellow: ILIACUS M: hip flexor
- light blue: iliospoas (iliacus + psoas major): hip flexor
Identify the 2 structures indicated by the arrows.
- arrow on left: suprarenal glands (=adrenal glands)
- arrow on right: kidneys
Identify the various structures.
DIAPHRAGM
- green: CAVAL HIATUS: where the inferior vena cava exits the diaphragm at T8
- orange: ESOPHAGEAL HIATUS: where the esophagus enters the diaphragm at T10
- purple: AORTIC HIATUS: where aorta enters the diaphragm at T12
Identify the various structures and their function.
- green: right crus
- blue: left crus
- CRUS: anchors diaphragm to spine and formes hiatus - red: lateral arcuate ligament: goes over the quadratus lumborum m and anchors the diaphragm
- purple: medial arcuate ligament: goes over the psoas minor &major and anchors diaphragm
- orange: median arcuate ligament: forms the aortic hiatus
Why is D4 of the duodenum ascending?
due to suspensary ligament that anchors it to posterior abdominal wall
Describe the trajectory of the subcostal n in the posterior abdomen.
the subcostal n (T12) (not part of the lumbar plexus) travels between the internal oblique m and the transversus abdominis m and becomes the thoracoabodminal n
Describe the lumbar plexus of the lumbosacral plexus.
- iliohypogastric L1
- ilioinguinal L1
- genitofemoral L1, L21
- Lateral femoral cutaneous L2, L3
- femoral n L2, L3, L4
- obturator n L2, L3, L4
Identify the various posterior abdominal viscera and their function.
a. suprarenal glands (adrenal glands): releases adrenaline
b. kidneys: between T12-L3: filters blood to retain water and sends urine to ureter
c. ureters: sends urine to bladder
d. bladder = pelvic organ
Explain the positioning of the kidneys.
The kidneys are found between T12-L3
the right kidney is lower than the left kidney because of the liver (like the flexures of the colon)
Are the kidneys retroperitoneal or intraperitoneal? What surrounds the kidneys?
RETROPERITONEAL: peritoneum sits anterior to kidneys against posterior abdominal wall
-packed in fat
(the picture shows the left kidney)
Identify these two structures.
red: renal artery: very big because blood gets filter through kidney
blue: renal vein: in front of the renal artery bc dont want it to be compressed against the posterior abdominal wall and is a lot bigger than the renal artery
How do you know if you are looking at the right or left kidney?
use the hilum of the kidney (in green) to orient yourself: the renal vein is always infront of the renal artery which is always in front of the ureter
left picture: anterior view => left kidney
right picture: posterior view => right kidney
Identify these 2 structures of the kidney.
upper arrow: FIBROUS CAPSULE: bc the kidneys are retroperitoneal, the whole kidney is not all covered by peritoneum => has its own shell
lower arrow: RENAL CORTEX
Identify the various parts of the kidney.
A. Renal columns
B. Renal cortex: gives renal columns down into medulla but still part of medulla because highly vascularized
C. Renal pelvis
D. Ureter
Blue: renal medulla: highly vascularized
orange: renal pyramids: between renal columns: where filter and exchange occurs
purple: major calyx (calyces)
green: minor calyx