Endocrine and Urinary Flashcards
epithelium
fenestrated
filtration
dependant on intrinsic and systemic factors
maintained at same rate
RAAS
RAAS
renin released by kidney in response to low BP –> angiotensin –> angiotensin I –> angiotensin II –> aldosterone release at adrenals
tubules function
reabsorption of water, glucose, electrolytes and bicarbonate
controls urine concentration - so if USG problem usually here
kidney functions (5)
eliminating waste
acid base regulation
conservation of water
maintenance of electrolyte balance
other metabolic and endocrine functions
routes of infection
ascending - eg. pylonephritis - bacteria ascends from bladder up ureters
hematogenous - from blood (kidneys have a lot of blood vessels)
toxins
direct toxins - administered directly to the animal –> necrosis of tubular cells
toxic metabolites - metabolism in liver produces toxins which damage kidneys
intrinsic toxins - eg. hemoglobin or myoglobin in high concentrations. (rhabdo or maple poisoning)
ischaemia
sudden drop in blood flow to kidneys
acute - sepsis, heatstroke, thromboembolism, acute haemorrhage, shock
chronic - congestive heart failure
drugs that affect blood flow to the kidneys
hydronephrosis
dilation of renal pelvis - fills with urine
usually due to downstream damage
increased pressure –> urine forced into interstitium –> collapse of vessels –> hypoxia –> repair by fibrosis
nephroliths
kidney stones
uroliths
ureter stones (also sometimes used for bladder stones)
cystoliths
bladder stones
methods of renal injury
infection
inflammation
toxins
neoplasia
function up to 75% functional loss
acute kidney failure types
pre renal - reduced blood flow
renal - tubular necrosis
post renal - urinary obstruction
azotemia
failure to eliminate waste - increased nirtogenous waste products, urea and creatinine
metabolic acidosis
inability to maintain acid-base balance
hypertension
inability to maintain blood volume and pressure
uremia
systemic changes associated with azotemia - build up of uremic toxins (creatinine, urea)
chronic kidney failure
nephron damaged –> replaced by fibrosis
eventual azotemia and uremia
signs - hypertension, anemia, hypokalemia, calcium deposition in soft tissues
morphology - pale tan colour, multi-focal depression in cortex, scar tissue from healing by necrosis, small, pale shrunken, knobbly kidneys
calcium homeostasis
kidneys key in regulating
involves kidney, gut, bone, thyroid and parathyroid
role of kidney - reabsorption in tubules, phosphate excretion, activation of vitamin D (reabsorbs calcium from the intestine)
low calcium –> PTH release –> more calcium released from bones –> weak bones
can lead to secondary hyperparathyroidism from excess PTH production
congenital disorders of kidneys
aplasia - never formed
hypoplasia - small kidneys
dysplasia - abnormally formed
renal dysplasia
progressive juvenile nephropathies (PJN) - heritable collagen defect (common in samoyeds)
polycystic kidney disease (PKD) - types 1 & 2 - 1 dominant so can be tested and bred out, 2 is autosomal recessive
renal neoplasia
renal cell carcinoma
urothelial cell carcinoma
lymphoma - metastasises to kidney
Pathology of endocrine system
over or under production of hormones
inability to respond to hormone production
exogenous hormone administration (iatrogenic)
production of hormone-like substance from neoplasia (eg PTH like hormone from anal sac carcinoma)
underproduction due to immune mediated destruction of endocrine organ
overproduction usually due to hyperplasia or neoplasia