lecture 1 Flashcards
what 4 things does urinary tract comprise of
kidneys, ureters, urinary bladder, urethra
urinary apparatus in sequence
kidneys - ureter - urinary bladder - urethra
where does abundant kidney blood supply come from
short direct renal arteries from abdominal aorta
what does blood pressure drive in kidneys
ultrafiltration by glomerular capillaries
what drains kidneys
renal veins into inferior vena cava (posterior abdominal wall)
left of midline is abdominal aorta, right of midline is inferior vena cava
right renal artery longer than left, passing behind IVC; left renal vein longer than right, passing in front of aorta but underneath superior mesenteric artery - aneurysm; superior to inferior: coeliac axis to forgut, midline of superior mesenteric artery to midgut, renal arteries, paired gonadal arteries from anterior surface of aorta, inferior mesenteric artery to hindgut; gonadal veins drain asymmetrically (right to renal vein to IVC, left straight to IVC)
what is the renal pelvis
the broaded superior section of ureter into which kidney tubules drain
developmental lobules
usually coallesce into one structure; cortex and medulla (renal pyramid)
why is the cortex granular-looking
random organisation
why is the medulla striated
radial arrangement of tubules and micro-vessels
what is the significance of a multilobar kidney
each lobe drains through its own papilla and minor calyx; all minor calyx drain into major calyx
structure of multilobar kidney
cortex in between lobules of medulla (renal columns of cortex)
renal artery drains into interlobular artery - becomes arcuate artery and merges with neighbour - nephron
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where do ureters run vertically down
posterior abdominal wall in vertical plane of tips of transverse processes of lumbar vertebrae
where do ureters cross pelvic brim
anterior to sacro-iliac joint and run over bifurcation of common iliac arteries
where do ureters enter bladder wall obliquely having descended anteromedially
level of ischial spine
long so complicated blood supply - from every major vessel crossed: renal arteries, gonadal arteries, common iliac, internal iliac arteries and branches, some small from abdominal aorta; ureters run down from tips then forward to enter posterior section of bladder
only lose blood supply to one part and entire ureter becomes unfuctional
how is urine transported in ureters
by peristalsis of their smooth muscle walls
3 sites of ureteric constriction
pelviureteric junction (renal pelvis and ureter), where ureter crosses pelvic brim, where ureter traverses bladder wall
what are constrictions
sites of renal colic (pain) caused by kidney stones attempting to pass, being stuck in narrowest parts of ureter - pain worse as ureter contracts
transitional mucosal endothelia; tight junctions; layers move over each other so appears multi-layered; impermeable to urine; submucosa then circular smooth muscle
commonest is pelviureteric junction as first one
structure of bladder
pelvic organ in adults (in children, abdominal); shaped like a triangular pyramid, with apex pointing anteriorly and base (fundus) posteriorly
what lines bladder
urothelium (transitional epithelium)
what is significance of 3-layered epithelium in bladder
if stretched become one layer; very slow cell turnover
