Gut book 6: Kidneys, ureters, & Suprarenal Gland Flashcards
Kidney- general description
Paired retroperitoneal abdominal organs which lie on either side of the vertebral column within the paravertebral gutters
Paravertebral gutters
formed by the intersection of three muscles: the psoas major overlaying the vertebral column, the quadratus lumborum, and the transversus abdominis muscle passing forward along the course of the ribs.
Kidneys: function
by filtering the blood, function to remvoe/ conserve H2O, remvoe metabolic waste, balance Na+ and K+ through selective secretion/ reabsorption, reabosorb glucose and amino acids, and participate in the renin-angiotensin system.
Comparison of kidneys
left kidney is somewhat longer than right
right kidney is slightly lower than left due to presence of liver
Kidneys: physical position
inferior poles lie more laterally than do superior poles
hilar area faces anteromedially due to the slope of the paravertebral gutter
vertebral projection: T12-L3 (LEFT: T12-L2; RIGHT: L1-L3)
retroperitoneal; embedded in layers of fascia and fat
Renal fascia and fat- derivation and function
derived from extraperitoneal connective tissue; support and protect the kidneys
Renal fascia
anterior and posterior lamina surround both kidneys, their associated suprarenal glands and invest the intervening renal vessels, aorta and IVC
The laminae overlap in the midline, fuse and adhere to the intervening vascular structures across the spine such that each kidney is isolated in its own compartment
Prolonged along the ureter as PERIURETERIC fascia
open inferiorly
periureteric fascia
prolongation of the renal fascia along the ureter
Types of renal fat
perinephric and paranephric
Perinephric- located internal to the renal fascia in direct contact with the kidney; surrounds the kidney and helps to locate it on the posterior abdominal wall
paranephric- retroperitoneal fat external to the renal fascia located posteriorly between the kidney and the quadratus lumborum/ diaphragm
perinephric abscess
due to the position of the renal fascia, perinephric abscess can lead to inflammation of the psoas major fascia (psoas abscess), which can descend from the abdomen to the pelvis or femoral triangle. Note that due to the fusion of the renal fascia in the midline surrounding the aorta and IVC, perinephric abscess cannot cross the midline to the opposite kidney.
nephroptosis
Due to the inferior opening of the renal fascia, kidneys can “drop” resulting in pain due to the kinking of the ureters.
Renal ectopia
kidney not located in its normal anatomic position
can be distinguished from nephroptosis in that in the former, the ureters are not kinked.
discuss placement of transplanted kidneys
Transplanted kidneys are placed in the iliac fossa so that the re-anastomosed vessels and ureter are not under any traction and remain patent
Right kidney- anterior relations
posterior abdominal wall peritoneum right suprarenal gland right lobe of the liver 2nd part of hte duodenum right colic flexure small intestine
left kidney- anterior relations
posterior abdominal wall peritoneym left suprarenal gland stomach spleen pancreas left colic flexure small intestine (jejunum)
posterior relations- right and left kidney
diaphragm psoas mm quadratus lumborum transversus abdominis lumbocostal arches (lateral and medial arcuate ligaments) subcostal n. iliohypogastric and ilioinguinal nerves
rib protection for kidneys
Within the musculofascial composition of the posterior abdominal wall ribs 11 and 12 provide protection for the posterior surface of the left kidney, while only the 12th rib affords protection for the right kidney
Kidneys: external structure
ovoid in shape in both the superior-inferior and anterior-posterior dimension
approx size: 10x5x2.5 cm
reddish brown in color in the fresh state
Surfaces: anterior and posterior
poles: superior and inferior
borders or margins: lateral- convex, medial- somewhat concave due to the presence of a central indented hilum
Renal capsule
fibrous connective tissue layer on the external surface of kidney
hilum
area through which renal vessels (aa., vv., & lymphatics), renal pelvis, and renal plexus enter and exit the kidney
renal sinus
area inside hilum, internal to the kidney containing vessels (aa., vv., & lymphatics), nerves, renal pelvis, calyceal system and perinephric fat
Kidneys: internal structure
divisible into five vascularly defined lobes or segments
cortex
medulla
cortex of the kidney
outer more granular appearing layer (due to the presence of glomeruli)
Medulla of the kidney
inner more striated zone due to the presence of straight tubules and collecting ducts; organized into pyramids (8-18) the bases of which face the cortex
medullary rays
portions of the medulla that extend into the cortex