19. Posterior Abdomen Flashcards
(36 cards)
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
Explain the trajectory of fluid through the kidneys.
renal pyramid -> after filtering drains into minor calyx -> major calyx -> renal pelvis -> ureter (with the help of gravity) -> bladder -> urethra
What causes kidney stones? What can it become?
kidney stones: crystallized waste products that can move down and then move into ureter = ureter stone, then can move down into bladder = bladder stone
(youd have to secrete out from the urethra)
Why are females more likely to have an urinary tract infection?
because females have shorter connection between outside and bladder whilst men have a longer connection allowing more time for the infection to stop
Describe the posterior abdominal blood flow.
A. inferior phrenic a: (T12) main blood supply to diaphragm and to dome of diaphragm
B. suprarenal A: goes to suprerenal gland
C. Renal a: (T12/L1) to kidneys
D.Gonadal a (L2) (either testicular a or ovarian a): supplies gonads and travels under the ureter (F) (water under the bridge)
E. Common iliac a (L4/L5): bifrication of aorta into internal iliac a (goes to pelvis) and into external iliac a (which becomes the femoral a)
What is a horseshoe kidney?
during growth, whilst testes descend, the kidneys ascend because they start as one. However, if the kidneys and testes dont fully separate, they get can stuck at the IMA = horseshoe kidney
When performing an arteriole bypass, why does it not impact the thorax when using the internal thoracic a for the bypass?
no loss of blood because of the inferior phrenic a which has many branches and can supply blood to regions loss by the internal thoracic a
Where do surgeons insert the kidneys during a kidney transplant?
connect the vessels of the hilum of the kidney to the common iliac A and V
Explain the posterior abdominal venous drainage.
- R/L renal vein drain into the IVC: left renal vein is longer because has to cross the aorta
- Gonadal vein:
- right gonadal vein drains back directily into the IVC (bc IVC is more on the right)
- left gonadal vein drains back into the left renal vein -> IVC - common iliac b drains back into IVC
Explain renal vein compression.
the SMA goes over the left renal vein and if theres a lot of fat or high BP, the sma can squeeze the left renal v which causes varacacies in both the left renal v and the left gonadal v (drains into the left renal!) => in men, if you have enlarged v in scrotum
