Renal Anatomy Flashcards
What is the function of the urinary system?
Regulation of body fluid and electrolyte balance to maintain BP by blood filtration.
With which system is the urinary system closely related to?
Genital system. Common final pathway (urethra) in men.
What is the function of the kidneys?
Maintain homeostasis by blood filtration.
What is the function of the ureters?
Carry urine from the kidneys to the bladder.
What is the function of the bladder?
Temporarily stores urine (walls expand to hold it and then contract to excrete it)
What is the function of the urethra?
Tube that allows urine to pass from bladder out of the body.
Where do the kidneys lie?
In the paravertebral gutters on the posterior abdominal wall either side of vertebral column at level T12-L3.
Where does the hilus of the kidney lie?
Transpyloric plane (L1).
What is the hilum of the kidney?
Concave border where BVs and renal pelvis enters/leaves the substance of the kidney.
Which kidney is lower and why?
Right - presence of liver.
What are the four layers enclosing the kidneys?
- fibrous renal capsule
- fatty renal capsule
- renal fascia (fibrofatty tissue)
- pararenal fatty tissue
Why is the kidney surrounded by so much fatty tissue?
As there are no bones to protect it from trauma.
Do the kidneys move on inspiration?
Yes - descend on inspiration, rise on expiration.
With which two muscles are the kidneys closely related?
Psoas major and quadratus lumborum.
How are the kidneys peritonised?
Retroperitoneal.
What structures will come in contact with the kidneys?
Liver, suprarenals, duodenum, colon, jejunum, small bowel, colonic flexure, pancreas, stomach, spleen.
What is the sympathetic supply to the kidneys?
T12-L1 spinal segment nerves which pass through celiac ganglia and run with the renal artery to the kidneys.
What is the parasympathetic supply to the kidneys?
Vagus.
Where does lymph from the kidneys drain into?
Para-aortic lymph nodes around the origin of the renal arteries (L1).
Describe the appearance of a horseshoe kidney.
Inferior poles of two kidneys have fused, can have abnormal insertion of ureters. People with horseshoe kidney are at increased risk of hydronephrosis, stone formation, tumours and infections.
What causes a duplicated ureter?
Duplication of the ureteric bud from the mesonephric duct. Can result in UTIs and vesicoureteric reflux.
What comprises the internal structure of the kidneys?
Renal cortex around the outside. Renal medulla in the inside. Minor calyces feed into major calyces which feed into he renal pelvis. Renal pelvis narrows into the ureter.
What structures of the nephron are present in the cortex of the kidney?
Distal and proximal convoluted tubules and the glomeruli.
What structures of the nephron are present in the medulla of the kidney?
Collecting ducts and loops of Henle.
Describe the histological structure of a glomerulus.
Bowmen’s space lies between the parietal layer of Bowman’s capsule and the visceral player (podocytes).
What is the blood supply to the kidneys?
Renal arteries.
Where are the renal arteries given off the abdominal aorta?
L1-2 VL (just below superior mesenteric).
Describe how the arteries divide after they enter the kidney.
They first divide into segmental arteries, which divide into interlobular arteries, then into arcuate arteries. Interlobular arteries pass into the cortex forming afferent arterioles (and eventually glomeruli).
What are the differences in how the right and left renal vein travel from the IVC to the kidneys?
Left renal vein travels anterior to the aorta and is relatively long. Right renal vein travels directly to the kidney and is much shorter.
What are the differences in how the right and left renal arteries travel from the aorta to the kidneys?
Right renal artery travels posterior to IVC and is relatively long, while right renal artery travels directly and is relatively short.
Where do the testicular/ovarian veins drain into?
Left - left renal vein.
Right - IVC directly.
How are the ureters peritonised?
Retroperitoneal.
What are the ureters?
Distensible, msucular tubes connecting the kidneys to the bladder.
On which muscle does the ureter descend as it travels to the bladder and which artery does it cross?
Psoas major and crosses bifurcation of the common iliac artery.
What structure crosses the ureters?
Ductus vas deferens in males and ovarian arteries in females.
Where are the three constrictions of the ureter?
- the origin (where renal pelvis narrows to form ureters)
- pelvic brim (where ureters cross posterior part of iliac crest)
- vesicle-ureteric junction (where it enters the bladder)
What crosses the apex of the bladder?
The median umbilical ligament as it ascends to the umbilicus. This is a remnant of the allantois (the canal that drains urinary bladder and joins to the umbilical cord).
What kind of muscle makes up the bladder?
Mostly detrusor muscle (smooth muscle).
What structure does the bladder lie behind?
The pubic symphysis.
Parietal peritoneum drapes over superior surface of bladder and dips down posterior surface to form what?
Peritoneal pouches.
What is the trigone of the bladder?
Smooth triangular region of internal bladder formed by 2 ureteric orifices and internal urethral orifice.
What sort of epithelium lines the urinary bladder and ureters?
Uroepithelium (multi-layered transitional epithelium - allows stretch when bladder fills). It has a GAG layer - which enables storage of urine without a high osmotic gradient.
What is the urethra?
Tube arising from the inferior part of the urinary bladder and carries urine from bladder to the exterior.
What is a good thing to remember when interpreting X-rays and trying to find the ureters?
They are in line with the transverse processes of lumbar vertebrae.
