Urinary Flashcards
what clinical conditions are associated with the kidney?
kidney failure (acute and chronic), calculi (stones), tumours, incontinence, infection, injuries
shape of kidneys in the dog?
‘kidney’ shaped
characteristics of kidneys in cat?
capsular, lots of veins
which animals have similar kidneys to sheep?
goats, rabbits
shape of pig kidney?
flattened
characteristics of ox kidney?
lobated, unusual looking
characteristics of horse kidney?
left is J shape/L shape, right is heart shape/r shape
which species has a lobated kidney?
ox
which species has a flattened kidney?
pig
which kidney is cranial?
right
in which species may the left kidney be cranial?
pigs
location of carnivore left kidney?
L2-4
location of carnivore right kidney?
L1-3
location of ox left kidney?
L2-4, on right
location of ox right kidney?
L1-3
location of horse left kidney?
last T vertebra- L3
location of horse right kidney?
T16-L1
location of pig left kidney?
last thoracic vertebra-L3
location of pig right kidney?
last thoracic vertebra-L3
which kidney is mobile/pendulous?
left
in which species does the left kidney rotate 90 degrees?
ox
how is the mobile left kidney useful in cat euthanasia?
helpful to hold left kidney through left body wall and inject euthanasia directly into kidney- veins usually collapsed so this is useful and quicker
what is the additional attachment of the kidney in the horse?
nephrosplenic ligament
which species has a nephrosplenic ligament?
horse
what does the equine nephrosplenic ligament attach?
left kidney to spleen
what happens in nephrosplenic entrapment?
colon (left ventral and dorsal) distends, becomes buoyant, floats up L flank to hook over nephrosplenic ligament- leads to pain and can cut off blood supply to spleen causing splenic engorgement
what are the treatments for nephrosplenic entrapment?
fluids, food restriction, exercise, rolling, phenylephrine to cause splenic contraction, surgery
how does the kidney start in embryonic development?
starts multilobar and multipyramidal
what happens to the kidney as the embryo develops?
progressive fusion of lobes and pyramids
which species have unipyramidal (fusipyramidal) kidneys?
dog, cat, horse, sheep, rabbit
which species have multipyramidal, unilobar kidneys?
human, pig
which species have multilobar, multipyramidal kidneys with a pelvis?
no domestic animals, dolphins
which species have multilobar, multipyramidal kidneys with no pelvis?
ox
appearance of the kidney cortex?
granular, brown
appearance of the kidney medulla?
paler than cortex
where do ureter, artery and vein connect to kidney?
at hilus
what is a pyramid?
cone of medullary tissue
what is a papilla/apex?
tip of pyramid
what is a calyx?
diverticulum of the pelvis
what do the pyramids fuse into in unipyramidal kidneys?
renal crest
what surrounds the kidneys?
fibrous capsule
what is the renal crest?
ridges of medulla running from both ends of kidney
what are pseudopapillae?
lobar pattern still evident as bulges along the renal crest
what is the pelvis? (kidney)
cavity that contains urine before it goes into ureter
why is there a void down the middle of pelvic casts? (kidney)
where renal crest sticks in
what does the ox have instead of a pelvis? (kidney)
separate calyces that don’t drain into one cavity
what are the terminal recesses in the horse kidney?
large tubes, extension of either end of renal pelvis
what is a renal corpuscle?
a glomerulus and Bowman’s capsule
where does urine drain from Bowman’s capsule?
PCT -> LoH -> DCT -> CD -> papillary duct then into calyx then into pelvis
what is the first branch of arteries in the kidney medulla?
interlobar
what branches off interlobar arteries?
arcuate arteries
what branches off arcuate arteries?
interlobular arteries
what branches off interlobular arteries?
afferent arterioles
what route does blood take from afferent arterioles in the kidney?
-> glomerular capillaries -> efferent arterioles ->vasa recta
why do kidneys get wedge-shaped infarcts?
no anastomoses/collateral circulation between any of the blood vessels so if any blockage then whole wedge will die off
what provides sympathetic innervation to kidneys?
aorticorenal ganglia
what provides parasympathetic innervation to kidneys?
vagus -> renal plexus
what is parasympathetic kidney innervation responsible for?
kidney pelvis and ureter motility
what is sympathetic kidney innervation responsible for?
controls BP
what provides pain sensory innervation to kidneys?
splanchnic nerves
what is the parenchyme? (kidney)
cortex and medulla of kidney
what is the sinus? (kidney)
pelvis, fat, vessels (anything that isn’t cortex and medulla)
why is equine urine turbid (cloudy)
glands discharging into pelvis of equine kidney secrete mucus
the kidneys are said to be retro-…?
retroperitoneal
in which species does the left kidney particularly seem to hang on a mesentery?
ruminants and cats
what is the layer outside the fibrous capsule around the kidneys?
the perirenal fat- thick protective fatty layer
what is suet?
perirenal fat
what does the perirenal fat lie in?
the sublumbar fascia
what does the usefulness of plain radiographs for imaging kidneys depend on?
fat contrast
lagomorph calcium metabolism?
uncontrolled gut absorption, high plasma concentration, little liver/gut excretion, used for continual tooth growth and preventing osteodystrophy, excess excreted in urine- calcium carbonate sludge precipitates in alkaline urine
which environment causes species to adapt to have a larger kidney medulla?
arid conditions
where are the adrenal glands located?
cranial/medial to kidneys, further than in humans, dorsal to phrenico-abdominal vein in dog
what does the zona glomerulosa (adrenal gland) release?
mineralocorticoids
what does the zona fasciculata (adrenal gland) release?
glucocorticoids
what does the zona reticularis (adrenal gland) release?
sex steroids
what does the medulla of the adrenal gland release?
catecholamines
what does the medulla of the adrenal gland develop from?
neural crest
what does the cortex of the adrenal gland develop from?
intermediate mesoderm
what is a condition caused by hyperadrenocorticism?
Cushing’s disease
symptoms of Cushing’s disease in dogs?
bilateral symmetrical alopecia, polyuria/polydipsia, potbellied, slack tendons and skeletal muscle wasting, weight gain (increased appetite), immune suppression
symptoms of Cushing’s in horses?
shaggy coat, laminitis, polyuria/polydipsia, sweating
what is a condition caused by hypoadrenocorticism?
Addison’s disease
what is Addisonian crisis?
collapse, hypotension, bradycardia
what are the symptoms of Addison’s disease if glucocorticoids, mineralocorticoids and sex hormones decreased?
decreased BP, Na+ decrease, K+ increase causing arrhythmia, glucagon decreases
what does the kidney develop from?
intermediate column of mesoderm
what is the earliest phase of kidney development?
pronephros (primitive tubules) develop in the cervical region, serves as starting point for mesonephric duct
what is the template on which the kidney is built?
the mesonephric duct
what develops in the second phase of kidney development?
mesonephros
what does the mesonephros consist of?
mesonephric duct that runs cranio-caudal and opens into the cloaca, and the nephric tubules
in what order do the nephric tubules form?
cranio-caudal succession with cranial ones first, then thoracic then abdominal
why are they usually 30 nephric tubules at any 1 time during development?
the earlier ones degenerate as the later ones form
what is the function of the mesonephros in the embryo?
acts as intermediate kidney, produces dilute urine important in maintaining the composition of the amniotic fluid
what is mesonephros size in inverse proportion to?
permeability and excretory effect of the placenta
in which species is the mesonephros large due to less well-developed placenta?
pigs
where do the true kidneys (metanephroi) develop?
sacral region
where do the ureteric buds form?
on the caudal end of the mesonephric duct
what do the ureteric buds grow out into?
the surrounding caudal part of the intermediate mesoderm
what do the cells surrounding the ureteric buds form?
condense to form the metanephric blastema
what develops from the ureteric buds?
the final kidneys
what evidence is there that communication between the ureteric bud and surrounding cells via secreted proteins is needed for the kidney to develop?
artificially placing a barrier that prevents the proteins from moving between cells stops kidney development
what proteins are released by ureteric buds for kidney development?
Wnt signalling proteins
how does the metanephros develop?
ureteric bud branches, fusion and resorption of the earliest branches creates terminal expansion (pelvis and calyces), further branching creates collecting ducts, tips of branches induce tubule formation in surrounding cells
where is ureteric bud branching and growth greater? what does this cause, particularly in horses?
at the poles- leading to kidney shape- in horse more pronounced- more heart shaped
what causes lobed appearance of the ox kidney?
tubules/medulla associated with one branch remain distinct
what are the stages of tubule development in the kidneys?
induced by tips of ureteric bud branches, aggregations of metanephric mesenchyme, basement membrane on outer surface of epithelial cells, polarisation of cells, final functional nephron
what is located in the kidney cortex?
renal corpuscles and most of the nephric tubule
what is located in the kidney medulla?
many renal tubules and collecting ducts
what animals have a mesonephros as the functional mature kidney?
fish, amphibians
what causes agenesis of the kidney?
failure of the ureteric bud to reach the caudal mesoderm at the right time
what are ectopic ureters?
when the ureter empties urine into another location other than the bladder
what causes ectopic ureters?
premature branching of the ureteric bud
what problems can ectopic ureters cause?
incontinence, infection due to reflux of urine from main ureter into secondary ureter and back into kidney
which sex is more likely to have ectopic ureters?
females
where do ectopic ureters terminate in the female?
vagina, urethra or uterus
where do ectopic ureters terminate in the male?
urethra
which is more common, unilateral or bilateral ectopic ureter?
unilateral
why may some males with ectopic ureters be continent?
longer length of the male urethra
how can ectopic ureters be diagnosed?
endoscopy to visualise ureteral opening into vagina or radiographic contrast studies + intravenous pyelogram
what are polycystic kidneys?
when dividing cells of ureteric bud have random orientation rather than alignment
when will dogs typically exhibit symptoms of juvenile kidney disease?
when less than 25% of renal function remains
early symptoms of juvenile kidney disease?
drinking copiously, frequent urination, dilute urine, puppies may fail to thrive
what are indicators of renal disease?
elevated blood urea nitrogen, protein in urine
what can happen to the bones of young dogs with hereditary kidney disease?
fibrous osteodystrophy- softening of the bones
what happens once the kidneys develop in the pelvic region?
have to ascend into abdominal region- as they ascend they receive blood supply from more rostrally up aorta, caudal branches usually regress, may persist giving extra renal arteries
where does the bladder develop from?
the cloaca (caudal region of gut tube, endoderm)
what separates the cloaca into the urogenital sinus and the rectum?
growth of the urorectal septum
where is the perineal body?
in between the urogenital sinus and the rectum
what is the upper part of the urogenital sinus?
urinary bladder
what is the urinary bladder initially continuous with?
the allantois
what happens to the connection of the bladder and allantois?
closes off leaving thick fibrous cord- the urachus
what forms from the most caudal part of the urogenital sinus?
the urethra (only the pelvic part in males, penile urethra develops from external genitalia)
what is entry into the bladder from the kidney initially via?
the mesonephric duct which links to the ureter and forms part of the male reproductive tract (the vas deferens)
what happens to the entry of the kidney into the bladder as the bladder grows?
caudal portion of mesonephric duct becomes incorporated into dorsal wall of bladder so ureters open directly into bladder
what causes the vas deferens to be looped over the ureter?
ureters pulled rostrally as kidneys ascend, mesonephric openings move caudally and closer together
what is the trigone?
triangular part of the dorsal region of the bladder made from the mesoderm of the incorporated duct region
where does the ureter go between?
renal pelvis to bladder
what does the ureter develop from?
intermediate mesoderm
outer layer of the ureter?
external loose adventitia
describe the muscle of the ureter?
outer circular muscle, inner longitudinal muscle
function of the outer longitudinal muscle layer of the ureter?
peristalsis
what type of epithelium is the urothelium?
transitional
describe the urothelium?
thickened membrane in surface cells, impermeable to anything larger than water, interdigitating cell junctions to allow stretching, coated with protective glycoprotein layer
course of ureter?
exits renal pelvis, passes directly caudally, runs dorsal to gonadal artery, ventral to external iliac, deep to circumflex iliac arteries
what drives contraction of the ureter?
sympathetic and mainly parasympathetic nerves (parasympathetic supply from vagus and pelvic nerves)
location of bladder in carnivores vs ungulates?
mainly abdominal in carnivores, more pelvic/retroperitoneal in ungulates
characteristics of the bladder muscle?
complex 3 layered intermingling smooth detrusor muscle
what smooth muscle structure is present at the outlet of the bladder into the urethra?
internal bladder sphincter (really just part of proximal urethra)
what is the site of urothelial carcinoma?
the bladder
what is the bladder wall made of?
muscular with urothelium surface
where do the ureters enter the bladder?
dorsally into bladder ceiling
where does the urethra exit the bladder?
caudally
how does the bladder hold the ureters closed at rest? what issue could this cause?
pressure in bladder blocks ureter- if bladder blocked then ureter blocked- urine builds up backwards into kidney
which end of the bladder swells as it fills?
the more mobile cranial end
what and where is the trigone?
stretched region of incorporated intermediate mesoderm in the bladder, from ureteric orifices to where vas deferentia would enter in males
attachment of rectum to dorsal body wall?
mesorectum
attachment of uteri to lateral body wall?
broad ligament
attachment of broad ligament of uteri to bladder? what does this develop from?
lateral vesical ligament - from umbilical arteries
what attaches the bladder to the ventral body wall? what does this develop from?
ventral vesical ligament- from old ventral mesentery of hindgut- contains urachal remnant which was originally fetal connection of hindgut to allantoic cavity
what is patent urachus?
opening of fetal connection of hindgut to allantoic cavity remains as tube emptying through navel, urine drips out
what positive contrast medium is used for the bladder?
iodine- barium is for intact gut only
difference in urethra lining between females and males?
in females all of urethra lined with urothelium, in male lined by stratified squamous epithelium at penis
what sort of muscle is the cranial ‘internal bladder sphincter’?
smooth muscle
what sort of muscle is the caudal ‘external bladder sphincter’?
striated urethralis muscle
difference in length of urethra in male and female?
longer in males
where does the urethra discharge in females?
the vestibule- common egress of urinary and reproductive tracts
where does the urethra discharge in males?
tip of penis
where does the urethra discharge in rams + billy goats?
urethral process
urethra issue common in males?
obstruction
urethra issues common in females? why aren’t they common in males?
cystitis and incontinence, cystitis more likely to be flushed out in males and have more urethralis muscle to clamp down to stop incontinence
what are the regions lateral to the cloacal/urethral folds called?
labrioscrotal swellings
what is at the bottom of the developing penile urethra?
genital tubercle
steps of development of the penile urethra?
urorectal septum forms and separates anus off- forms perineum which becomes scrotum in males. urethra folds lengthen in males- grow down and seal over to seal in tube- cord of ectoderm invades into glands- links to rest of urethra
what nerve is most important for urine retention?
pudendal nerve (S1-3) is somatic, causes urethralis contraction
what is the nerve supply to the alpha 1 and beta 2 receptor of the cranial bladder sphincter? what does it do?
hypogastric nerve, for detrusor relaxation, contributes to retention
role of pelvic nerve in urinary tract?
contributes to detrusor contraction to void urine
what non-nervous processes cause urine retention?
intra-abdominal pressure/bladder position and interlocking of urothelial folds in urethra
4 pharmacological treatments for incontinence?
alpha agonists increase urethral resistance, alpha antagonists decrease urethral resistance, cholinergics increase detrusor contraction, anticholinergics decrease detrusor contraction
