Gut book 6: Kidneys, ureters, & Suprarenal Gland

Question 1

Kidney- general description

Answer 1

Paired retroperitoneal abdominal organs which lie on either side of the vertebral column within the paravertebral gutters

Question 2

Paravertebral gutters

Answer 2

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.

Question 3

Kidneys: function

Answer 3

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.

Question 4

Comparison of kidneys

Answer 4

left kidney is somewhat longer than right

right kidney is slightly lower than left due to presence of liver

Question 5

Kidneys: physical position

Answer 5

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

Question 6

Renal fascia and fat- derivation and function

Answer 6

derived from extraperitoneal connective tissue; support and protect the kidneys

Question 7

Renal fascia

Answer 7

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

Question 8

periureteric fascia

Answer 8

prolongation of the renal fascia along the ureter

Question 9

Types of renal fat

Answer 9

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

Question 10

perinephric abscess

Answer 10

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.

Question 11

nephroptosis

Answer 11

Due to the inferior opening of the renal fascia, kidneys can “drop” resulting in pain due to the kinking of the ureters.

Question 12

Renal ectopia

Answer 12

kidney not located in its normal anatomic position

can be distinguished from nephroptosis in that in the former, the ureters are not kinked.

Question 13

discuss placement of transplanted kidneys

Answer 13

Transplanted kidneys are placed in the iliac fossa so that the re-anastomosed vessels and ureter are not under any traction and remain patent

Question 14

Right kidney- anterior relations

Answer 14

posterior abdominal wall peritoneum
right suprarenal gland
right lobe of the liver
2nd part of hte duodenum
right colic flexure
small intestine

Question 15

left kidney- anterior relations

Answer 15

posterior abdominal wall peritoneym
left suprarenal gland
stomach
spleen
pancreas
left colic flexure
small intestine (jejunum)

Question 16

posterior relations- right and left kidney

Answer 16

diaphragm
psoas mm
quadratus lumborum
transversus abdominis
lumbocostal arches (lateral and medial arcuate ligaments)
subcostal n.
iliohypogastric and ilioinguinal nerves

Question 17

rib protection for kidneys

Answer 17

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

Question 18

Kidneys: external structure

Answer 18

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

Question 19

Renal capsule

Answer 19

fibrous connective tissue layer on the external surface of kidney

Question 20

hilum

Answer 20

area through which renal vessels (aa., vv., & lymphatics), renal pelvis, and renal plexus enter and exit the kidney

Question 21

renal sinus

Answer 21

area inside hilum, internal to the kidney containing vessels (aa., vv., & lymphatics), nerves, renal pelvis, calyceal system and perinephric fat

Question 22

Kidneys: internal structure

Answer 22

divisible into five vascularly defined lobes or segments
cortex
medulla

Question 23

cortex of the kidney

Answer 23

outer more granular appearing layer (due to the presence of glomeruli)

Question 24

Medulla of the kidney

Answer 24

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

Question 25

medullary rays

Answer 25

portions of the medulla that extend into the cortex

Question 26

renal or cortical columns

Answer 26

portions of the cortex that extend toward the pelvis between medullary pyramids

Question 27

Intrarenal duct system

Answer 27

each pyramid has its apex (renal papilla) oriented twoard the renal sinus. Renal papilli drain via papillary ducts to a minor calyx Two or more minor calyces, of which there are eight, drain to a major calyx Two or three major calyces drain to the renal pelvis which in turn is drained by the ureter

Question 28

Renal arteries

Answer 28

left and right renal arteries branch from the aorta at approximately LV2 just below the superior mesenteric artery course transversely to reach the kidney, passing anterior to the crura of the diaphragm and psoas muscles the right renal artery courses posterior to the IVC, head of the pancreas, 2nd portion of the duodenum and right renal vein before entering the hilum.

Question 29

what else the renal arteries supply

Answer 29

each renal artery provides its corresponding suprarenal gland with an inferior suprarenal artery, and its corresponding ureter with ureteric branches.

Question 30

lobar or segmental arteries

Answer 30

Before entering the renal sinus, the renal arteries branch into segmental or lobar arteries Each of the five arterial lobar branches of the renal artery are "end arteries" which supply the five "segments" of the kidney.

Question 31

Interlobar arteries

Answer 31

branch from lobar arteries and course within renal cortical columns

Question 32

Arcuate arteries

Answer 32

reaching the junction of the cortex and medulla, the interlobar arteries provide arcuate arteries which course BETWEEN the cortex and medulla.

Question 33

Interlobular arteries

Answer 33

branch from the arcuate arteries to course peripherally within the cortex (perpendicular to the renal capsule). They will provide the afferent arterioles of the glomerulus.

Question 34

efferent arterioles

Answer 34

the direct continuation of the afferent arterioles form a plexus around the tubules of the kidney (peritubular capillary plexus)

Question 35

Veins of the kidney

Answer 35

drain in a pattern similar to the arteries, except that there are NO efferent or afferent venules. Renal veins exit the renal sinus, pass anterior to the renal arteries to join the IVC.

Question 36

What else does the left renal vein receive?

Answer 36

the left gonadal vein as well as the left inferior phrenic vein before passing ANTERIOR to the aorta to join the IVC

Question 37

vessels formed during renal development are sometimes...

Answer 37

retained as the kidney "ascends" from the pelvis leading to the existence of ectopic vessels which should have been resorbed as newer vessels formed.

Question 38

Renal Vein Entrapent Syndrome,

Answer 38

= nutcracker syndrome results from entrapment of the left renal vein between the superior mesenteric artery and aorta. Downward traction on the SMA by an engorged small bowel can also compress part three of the duodenum. Symptoms include hematuria, left flank pain, nausea, vomiting, and left testicular pain in males (left pelvic pain in females).

Question 39

Ureter- function

Answer 39

conveys urine from kidney to bladder

Question 40

Ureter- structure

Answer 40

thick walled muscular tube with a narrow lumen (approx 25-30 cm)

Question 41

Ureter- course

Answer 41

entire course is retroperitoneal Descends on the surface of the psoas muscle parallel to the tips of the lumbar transverse process, crosses the pelvic brim at the bifurcation of the common iliac a., course inferomedially on the lateral pelvic wall to gain the inferior surface of the urinary bladder. In the male, the ureter passes inferior to the ductus deferens; in the female, it passes inferior to the ovarian artery.

Question 42

What structures cross the ureters, respectively?

Answer 42

the right ureter originates behind the 2nd part of the duodenum and is crossed by the right colic and iliocolic and gonadal vessels as it descends. The left ureter is crossed by the gonadal, left colic and sigmoid vessels and the sigmoid colon.

Question 43

Ureter- arteries

Answer 43

upper 1/3- branches from the renal a. middle 1/3- branches from the gonadal a. lower 1/3- branches from the internal iliac a.

Question 44

Ureter- veins

Answer 44

follow arterial pattern to IVC

Question 45

Potential constrictions for renal calculi traversing the ureter

Answer 45

junction of renal pelvis and ureter crossing the pelvic brim junction of the ureter with the urinary bladder

Question 46

Components of the renal plexus on renal artery

Answer 46

Sympathetic- preganglionic fibers via lesser, least and lumbar splanchnic nn. (T10-L1) Postganglionic fibers from the aorticorenal ganglion and scattered ganglial cells located in the renal plexus Primary innervation is vasomotor to smooth muscle of the afferent and efferent arterioles Afferents (acute pain due to distension) travel via thoracic spinal nerves T10-12, L1

Question 47

Ureter- sympathetic innervation via

Answer 47

via: a. aorticorenal plexus (T10-12) (Lesser & Least Splanchnics) b. aortic plexus (L1-2) (Lumbar splanchnics) c. pelvic plexus via sup. & inf. hypogastric plexuses (lumbar & sacral splanchnics)

Question 48

Ureter- parasympathetic innervation

Answer 48

from the vagus via the celiac/ aorticorenal plexus

Question 49

pacemaker tissue in the wall of the renal pelvis

Answer 49

The autonomic role of ureteral innervation is not yet clear. However, pacemaker tissue in the wall of the renal pelvis responds to filling reflexively causing ureteric peristalsis (protection of delicate renal tissue from hydrostatic pressure of overfilling of the renal pelvis). It is thought that autonomic innervation modulates the overall peristaltic activity of the ureter.

Question 50

Visceral afferents for ureteric pain travel via

Answer 50

spinal nerves T11-12, L1,2

Question 51

Renal calculi

Answer 51

As renal calculi (kidney stones) descend the ureter, they distend it causing reflex smooth muscle contraction resulting in renal colic (pain and cramping sensation) that is referred sequentially from above downward, from flank or loin (mid to lower lateral back) to the inguinal region, to the scrotum/ labia. Pain may also extend to the anteromedial thigh via the reference zone of the genitofemoral n. (L1,2)

Question 52

Dermatomes of referred pain from kidney and ureter

Answer 52

Pain from the kidney refers to the T10-12 dermatomes, while pain from the ureter most often refers to the T11-L1 dermatomes.

Question 53

Hydronephrosis & calculi

Answer 53

When kidney stones become wedged in the ureter, the flow of urine is blocked and the kidney retains urine in the renal pelvis causing distension and pain. (hydronephrosis). If this condition is not alleviated rather quickly, the calyceal system becomes dilated and the hydrostatic pressure caused by the accumulation of urine will blunt the renal papillae, compress the renal pyramids and cortex leading to renal necrosis.

Question 54

inflammation/ abscess posterior to the kidney can result in..

Answer 54

irritation of the iliohypogastric and ilioinguinal nn. leading to reference pain at the anterior abdominal wall in the suprapubic and inguinal region dermatomes (T12-L1)

Question 55

Suprarenal (adrenal) gland structure

Answer 55

Paired endocrine glands located at teh superior medial aspect of each kidney encased in renal fascia right gland is pyramidal in shape; the left is crescentic approximately the size of a silver dollar; less than 1 cm thick has hilum on anterior surface

Question 56

Suprarenal gland- internal aspect

Answer 56

cortex- secretes steroid hormones necessary for life | Medulla- functions as a post ganglionic sympathetic neuron; secretes epinephrine and norepinephrine

Question 57

Suprarenal gland- arterial supply

Answer 57

superior suprarenal arteries- branches of the inferior phrenic a. Middle suprarneal artery- branches directly from the aorta just proximal to the origin of the renal artery Inferior suprarenal artery- branch of the renal artery Note: none of the suprarenal arteries enter the gland at the hilum

Question 58

Venous drainage of the suprarenal gland

Answer 58

Solitary large CENTRAL VEIN exits the hilum a. on the right side, the central vein drains to the IVC b. on the left side it drains with the infrior phrenic vein to the left renal v.

Question 59

Sympathetic innervation to the adrenal medulla

Answer 59

preganglionic sympathetic fibers originate from splanchnic nerves T6-8-T12, L1 Fibers travel to the gland via the celiac, aorticorenal, and renal plexuses Fibers synapse directly on chromaffin cells of the adrenal medulla.

Question 60

Chromaffin cells

Answer 60

secrete epinephrine and norepinephrine, therefore serving as postganglionic sympathetic nerve fibers.

Question 61

Sympathetic innervation to the adrenal cortex

Answer 61

thought to be mainly vasomotor

Question 62

Parasympathetic innervation to the adrenal cortex

Answer 62

Vagal parasympathetic preganglionic fibers from the celiac plexus are thought to innervate the suprarenal gland. Postganglionic PS terminals have been identified in both the cortex and medulla Postganglionic PS fibers are though tto play a role in vasomotor control in both the cortex and medulla

Question 63

Visceral afferent fibers of adrenal gland

Answer 63

have been demonstrated in both dorsal root ganglia of spinal cord levels T6-8-L1 and vagal nuclei in the brain.