11. Abdomen V Flashcards
What is the abdomenal course of the ureters?
1) Crosses over PSOAS major
2) Crosses over genitofemoral nerves (part of lumbar plexus, easy to identify as it always crosses over PSOAS major muscle)
3) Gets crossed obliquely by gonadal vessels (e.g. ovararian or testicular arteries)
4) Crosses the bifurcation of common iliac artery (L4/L5) to enter pelvis
What shape is the right suprarenal gland?
Pyramid
What shape is the left suprarenal gland?
Crescent
What is the nervous innervation of the kidneys?
Sympathetic:
Has vasomotor roles, regulating blood flow and renin secretion
It is from the renal plexus which follows the renal arteries
Post-ganglionic sympathetic from T10-L1
Parasympathetic:
This is contested as some texts state that parasympathetic fibres branch from vagus nerve however others say that there is no evidence of parasympathetic innervation of the kidneys.
Regardless, renal function is not dependent on innervation as is shown by renal transplants where the kidneys work just fine without being innervated.
Renal function is regulation โbyโ hormones.
What is the arterial โsupplyโ of the kidneys
Renal arteries, which divied into five segmental arteries (4 anterior and 1 posterior)
These then divide to lobar arteries, then interlobar arteries, arcuate artereis and then interlobular arteries
What are some characteristics about suprarenal glands?
- Endocrine glands
- present on upper/superior pole of kidneys
- the right suprarenal gland is pyramidal whereas the left suprarenal gland is crescent-shaped
- Suprarenal glands are surrounded by renal fascia, hence even if kidney is disturbed the suprarenal glands are shielded
- They contain a yellow cortex and a brown medulla
What is the yellow cortex of the suprarenal glands derived from?
Mesoderm
What is the brown medulla of suprarenal glands derived from?
Neural Crest
What is the function of the yellow cortex of the suprarenal glands?
Secretes androgens and corticosterioids
What is the function of the brown medulla of the suprarenal glands?
Secrete catecholamines (adrenaline and noradrenaline)
What are the three main arteries of the suprarenal glands and where do they branch from?
- Superior suprarenal artery - branch from the inferior phrenic artery
- Middle suprarenal artery - comes off aorta directly
- Inferior suprarenal artery - comes off renal artery
Where does the right suprarenal vein drain into?
IVC
Where does the left suprarenal vein drain into?
Left renal vein (more efficient than traversing aorta to get to IVC)
List some functions of the kidneys
- Acid-Base balance
- Excretes most waste products of metabolism
- Water and electrolyte balance of the body
- Secretes hormones and renin into the bloodstream
Kidneys filter around 113-114 pints of blood per hour
Filters all the blood in the body around 400 times a day
blood flow to the kidney is greater than to the heart
Are kidenys primary or secondary retroperitoneal?
Primary retroperitoneal
Which kidney is lower than the other and why?
Right is lower due to the presence of the liver above it (pushing it downwards)
What is the vertebral position of the kidneys?
Located between T12 and L3
What is the vertebral level of the hila of the kidneys?
L1
Which ribs surround the kidneys?
Ribs 11 and 12
Why do ribs move upon inspiration?
Because they are closely associated with the diaphragm
What are the anterior relations of the right kidney
- Superior pole - right suprarenal gland/adrenal gland (pyramid shape)
- Liver - anterior surface of kidney โin contactโ with liver, but separated by peritoneum (hepatorenal pouch of morison)
- Descending duodenum - close contact with hilum of right kidney
- Right colic flexure - in contact with lower lateral part of kidney
- Small intestine - lower medial side of kidney, separated by peritoneum
The surfaces of the kidney in contact with the liver and the small intestines are the surfaces which are โcoveredโ in periotoneum
What are the anterior relations of the left kidney?
- Superior pole - left suprarenal gland/adranl gland (crescent shape)
- Stomach - separated by perionteum
- Spleen - separated by peritoneium (lienorenal/ splenorenal ligament)
- Pancreas - middle part of kidney
- Left colic flexure - lateral middle part of kidney
- descending colon - inferior middle part of the kidney
- Jejunum - lower medial part of kidney, separated by pertoneium
Thus, surfaces in contact with the stomach, spleen, and jejunum have periteonum โcoveringโ it
What are the posterior relations of the kidneys?
Posteriorly, kidneys are closely associated with the muscles of the posterior abdomenal wall:
- Superior pole is closely associated with the diaphragm
- Medially kidneys are closely associated with the PSOAS minor/major muscle
- โMiddle laterallyโ kidneys are closely associated with quadratus lumborum muscle
- Laterally the kidneys are closely associated with the trasversus abdominus muscle
Label this image
What are the functions of kidney/renal coverings and what actually are they?
Kidneys are enclosed in many fascial layers which hold the kidney up in place against the posterior abdominal wall, and โsupportโ them.
- Renal Capsule - closely adherant with surface of kideny
- Perinephric Fat - within perineal space (perinephric fat is sandwiched between the renal capsule and the renal fascia)
- Renal Fascia - condensation of areolar connective tissue. Renal fascia is continuous with -transversalis fascia (inferiorly) and -fascia over diaphragm (superiorly)
- Paranephric Fat - external to the renal fascia
What is the renal capsule?
Touch fibroconnective tissue surrounding the renal cortex
What is the renal cortex?
Outer layer surrounding the renal medulla, contains nephrons and renal tubules
What demarcates the renal pyramids?
Renal cortex extends into the medulla as renal columns, demarcating the renal pyramids of the medulla, with the apex of the pyramid being the renal papilla which drains into minor calyx
What is the minor calyx
Structures receiving urine from collecting ducts of renal pyramids via the renal papillae
Major calyx
site at which many minor calyces drain
Renal pelvis
Site at which major calyces unite, conveys urine to the proximal ureter
Hilum
medial aspect of each kidney, where renal pelvis emerges fro kidney. Hilum is site at which vessels, nerves and lymphatics emerge from or enter the kidney.
Label this diagram
What is another way of describing the renal pelvis?
The dilated superior portion of the ureter
Structures in the renal hilum:
Renal artery, Renal Vein, Ureter
What fills the renal sinus?
Perinephric fat (surrounds structures like renal pelvis and hilum)
What is the order in which vessels and ureters enter/leave the hilum of the kidneys?
VAU = Vein, Artery, Ureter
What other structures pass through hilum?
Sympathetic fibres (e.g. least splanchnic nerves) and lymphatic vessels
What are the five vascular segments of the kidney?
1) apical (at the very top of the kidney)
2) caudal (at the very bottom of the kidney)
3) anterior superior
4) anterior inferior
5) posterior
Vascular segments arise as a result โofโ them being supplied โbyโ one of the five different segmental arteries
What are the arteries to the kidney?
- renal arteries (branch of aorta, L1/L2, right is longer than left)
- segmental arteries (five of them, four of which are anterior to the renal pelvis and one of which is posterior to the renal pelvis)
- Lobar arteries (going to lobe of kidney which is renal pyramid plus superior cortex)
- Branches into interlobar arteries which run in between the lobes
- These arch over the base of the pyramid as arcuate arteries
- Arcuate arteries give off more branches known as interlobular arteries (these extend into the cortex and give afferent glomerular arterioles for Bowmanโs Capsule)
What course do the renal veins follow?
Follow track of renal arteries
Which veins receive blood from efferent glomerular veins from Bowmanโs capsule?
Interlobular veins
Which arteries โgive offโ afferent glomerular arterioles to the Bowmanโs capsule?
Interlobular arteries
Label this image
How many times longer is the left renal vein than the right renal vein?
3x
What is relation of left renal vein to right renal vein when it enters the IVC?
Left renal vein enters IVC superiorly to right renal vein
Which side is preferred for live donor nephrectomy?
left (due to longer renal vein, less associated with renal vein thrombosis like the right as well as right having shorter vessels)
What is the effect of an aneurysm of the superior mesenteric artery
Can compress the left renal vein (because the superior mesenteric artery passes over it)
Which other veins drain into the left renal vein?
- left gonadal vein
- left inferior phrenic vein
- left suprarenal vein
What is the position of the right renal vein?
Posterior to the second part of the duodenum (descending duodenum) and head of pancreas
What is the route of the lymphatics of the kidney?
- Lymphatic vessels follow the route of the renal veins
- They then drain into the para-aortic nodes such as the right lumbar nodes (which are the pre-caval nodes, post-caval nodes and lateral-caval nodes in front, behind and to the side of the IVC respectively) and the left lumbar nodes (lateral to the aorta)
- These nodes then drain into the right and left lumbar trunks
- Right and left lumbar trunks then drain into the cisterna chyli
Is renal function dependendent on nervous innervation?
No, it is more to do with hormonal regulation.
In renal transplants there is complete transection of innervation and kidneys function just fine
Is there evidence of parasympathetic innervation of the kidneys?
Some texts suggest the vagus nerve has a role in parasympathetic innervation of the kidneys however more recent research shows there is no evidence of parasympathetic innervation to the kidneys
What is the function of the sympathetic innervation of the kidneys?
Vasomotor control, regulating blood flow and renin secretion
From the renal plexus which follows the renal artery
Pre-ganglionic fibres from T10 to L2
What causes staghorn caliculi?
Recurrent UTIs -> increase ammonia production -> increased pH -> decreased phosphate solubility
thus the phosphate accumulates into a calyx (renal stone)
How long is the ureter?
25-30cm
What type of contractions occur in the ureter?
peristaltic
What does the ureter continue from?
It begins as a continuation from the renal pelvis
What is the course of the ureter in the abdomen?
- descends anterior to the PSOAS major muscle
- descends anterior to genitofemoral nerve
- gets crossed over obliquely by the gonadal vessels
- traverses the bifurcation of the common iliac artery (L4/L5), at the level of the sacroiliac joint, the ureters enter the pelvic brim
Ureter course in the pelvis
- crosses anteriorly to internal iliac artery then reaches ischeal spine
- At the level of the ischeal spine, the ureter turns anteromedially to enter upper lateral angle of bladder
At the termination of the ureter, it gets crossed over by the vas deferens/ductus deferens in males or uterine artery in females
When the ureter enters the bladder, it passes obliquely through the bladder wall for 3/4 of an inch before opening into bladder cavity.
-this oblique angle of entrance of ureter into bladder is important to prevent backflow of urine.
What are bony landmarks which can be used to track course of the ureters?
Sacroiliac joint (where the ureters enter the pelvic brim)
and ischeal spine (where ureteres turn anteromedially to enter bladder)
What are effects of ureteric calculi on the muscular wall?
May cause distention
Also, can get ureteric colic which is severe pain due to contraction of ureteric muscles to overcome an obstruction usually due to stone or clot formation.
Ureteric calculi can also cause intermittent/complete obstruction of urinary flow
Why does ureteric colic cause pain?
Because ureter contracts and distends to try to move renal stone along - that muscular spasm causes a lot of pain
What are the ureteric constrictions
Regions of the ureter which are narrower and hence calculi get stuck here more easily
- ureteropelvic junction
- crossing over common iliac artery
- site of entrance to bladder
What arteries supply blood to the ureters?
- Renal artery
- Gonadal artery
- Common iliac arteries
- Internal iliac arteries
What is the maximum volume of urine the bladder can hold?
1L
What kind of organ is the bladder?
Extraperitoneal (sub-peritoneal)
What structure is the bladder posterior to?
Pubic symphysis
What is the location of the bladder?
When empty it lies in the lesser (true) pelvis, but when full it can extend into the abdominal cavity
What is the retro-pubic space of retzius?
โempty spaceโ between pubic bone/symphysis and the bladder (so a space anterior to the bladder)
What is the vesico-uterine pouch?
Pouch between bladder and uterus in females
What is the position of the anterior uterus and vaginal wall compared to the bladder?
Posterior
What is the recto-uterine pouch?
Pouch which is between rectum and uterus