lecture 1

Question 1

what 4 things does urinary tract comprise of

Answer 1

kidneys, ureters, urinary bladder, urethra

Question 2

urinary apparatus in sequence

Answer 2

kidneys - ureter - urinary bladder - urethra

Question 3

where does abundant kidney blood supply come from

Answer 3

short direct renal arteries from abdominal aorta

Question 4

what does blood pressure drive in kidneys

Answer 4

ultrafiltration by glomerular capillaries

Question 5

what drains kidneys

Answer 5

renal veins into inferior vena cava (posterior abdominal wall)

Question 6

left of midline is abdominal aorta, right of midline is inferior vena cava

Answer 6

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)

Question 7

what is the renal pelvis

Answer 7

the broaded superior section of ureter into which kidney tubules drain

Question 8

developmental lobules

Answer 8

usually coallesce into one structure; cortex and medulla (renal pyramid)

Question 9

why is the cortex granular-looking

Answer 9

random organisation

Question 10

why is the medulla striated

Answer 10

radial arrangement of tubules and micro-vessels

Question 11

what is the significance of a multilobar kidney

Answer 11

each lobe drains through its own papilla and minor calyx; all minor calyx drain into major calyx

Question 12

structure of multilobar kidney

Answer 12

cortex in between lobules of medulla (renal columns of cortex)

Question 13

renal artery drains into interlobular artery - becomes arcuate artery and merges with neighbour - nephron

Answer 13

-

Question 14

where do ureters run vertically down

Answer 14

posterior abdominal wall in vertical plane of tips of transverse processes of lumbar vertebrae

Question 15

where do ureters cross pelvic brim

Answer 15

anterior to sacro-iliac joint and run over bifurcation of common iliac arteries

Question 16

where do ureters enter bladder wall obliquely having descended anteromedially

Answer 16

level of ischial spine

Question 17

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

Answer 17

only lose blood supply to one part and entire ureter becomes unfuctional

Question 18

how is urine transported in ureters

Answer 18

by peristalsis of their smooth muscle walls

Question 19

3 sites of ureteric constriction

Answer 19

pelviureteric junction (renal pelvis and ureter), where ureter crosses pelvic brim, where ureter traverses bladder wall

Question 20

what are constrictions

Answer 20

sites of renal colic (pain) caused by kidney stones attempting to pass, being stuck in narrowest parts of ureter - pain worse as ureter contracts

Question 21

transitional mucosal endothelia; tight junctions; layers move over each other so appears multi-layered; impermeable to urine; submucosa then circular smooth muscle

Answer 21

commonest is pelviureteric junction as first one

Question 22

structure of bladder

Answer 22

pelvic organ in adults (in children, abdominal); shaped like a triangular pyramid, with apex pointing anteriorly and base (fundus) posteriorly

Question 23

what lines bladder

Answer 23

urothelium (transitional epithelium)

Question 24

what is significance of 3-layered epithelium in bladder

Answer 24

if stretched become one layer; very slow cell turnover

Question 25

what do large luminal cell membranes have

Answer 25

highly specialised low permeability luminal membrane

Question 26

significance of large luminal cell membrane

Answer 26

prevents dissipation of urine-plasma gradients

Question 27

what is the bladder apex attached to

Answer 27

median umbilical ligament; ureters enter bladder at posterior-superior angles, close ureters when enter bladder, preventing backflor; trigo of bladder - ureters and neck - flat, bladder cancers most likely to arise here

Question 28

posterior attachments to bladder in women

Answer 28

urthera, pubovesical ligament holds urethra in place, vaginal opening in deep perineal pouch and perineal membrane (urethra passes through perineal membrane - within lies external sphincter of urethra)

Question 29

posterior attachments to bladder in men

Answer 29

bladder separated from membranous structure by prostate; puboprostatic ligament, prostate (urether runs through prostate)

Question 30

anterior superior surface of full bladder

Answer 30

in abdomen so can puncture anterior abdominal wall to insert catheter; when rises upwards as full, pushes visceral perineum backwards so won’t enter perineal cavity when insert catheter

Question 31

what are the two urinary sphincters (internal and external)

Answer 31

sphincter vesicae (internal), sphincter urethrae (external)

Question 32

what is sphincter vesicae made from

Answer 32

smooth muscle

Question 33

what is sphincter urethrae made from

Answer 33

striated muscle

Question 34

where is sphincter vesicae located

Answer 34

at neck of bladder

Question 35

what is the reflex opening of sphincter vesicae in response to

Answer 35

bladder wall tension

Question 36

what nerves relax, and contract, sphincter vesicae

Answer 36

relaxed by parasympathetic nervous system, contracted by sympathetic nervous system

Question 37

where is sphincter urethrae located

Answer 37

in perineum

Question 38

what is tone maintained by in sphincter urethrae

Answer 38

somatic nerves in pudenal nerve (anterior division of ventral rami of S2, S3, S4)

Question 39

what is sphincter urethrae opened by

Answer 39

voluntary inhibition of nerves - must be learned

Question 40

urethra length in female - 4cm

Answer 40

internal: between bladder and prostate; external: below prostate

Question 41

describe reflex control of bladder

Answer 41

bladder fills - stretch receptors - parasympathetic nerve - bladder - bladder contracts (detrusor muscle) - internal urethral sphincter (vesicae) mechanically opens when bladder contracts; sympathetic innevration to internal sphincter closes off to prevent backflow of semen during ejaculation

Question 42

describe how reflex control of bladder is mediated by voluntary control

Answer 42

cerebral cortex stimulates motor neuron to ensure external sphincter (urethrae) remains closed

Question 43

describe what happens in bladder if stretch receptors fire so much because bladder is very full

Answer 43

negatively inhibits motor neurone so external sphincter opens

Question 44

how is urethra different in males and females

Answer 44

in males, have preprostatic, prostatic (in prostrate, vertical straight), memranous (external, through urogenital diaphragm), bulbar and spongy (penile; horizontal straight then vertical straight) parts of urethra; in females, straight and short

Question 45

in male urethra, what does internal urethral orifice at end of bladder contain

Answer 45

bladder neck, bladder outlet

Question 46

2 further parts of male urethra

Answer 46

navicular fossa (widening), external urethral meatus (where urethra ends)

Question 47

lymph drainage

Answer 47

urine normally sterile, but esp. in females can infect urethra (short, warm and moist environment in vagina); lymph drainage follows arteriole supply (valves so pulsation of arteries drive lymph upwards) in opposite direction - from bladder: nodes surrounding internal iliac, track up to common iliac, para-aortic nodes at gonadal arteries, inferior and superior mesenteric arteries