intro to nephro Flashcards
Glomerulus
tuft of capillaries interposed between the afferent and efferent arterioles-housed in an epithelial cell capsule: bowmans capsule.
filtrate must pass through 3 layers
fenestrated endothelial cell, glomerular basement membrane, epithelial cell
JGA
contains macula densa and JG cells located in the afferent arteriole. JGA cells also synthesize and store prorenin which is cleaved into active renin and secreted into the afferent arteriole in response to renal hypoperfusion
tubuloglomerular feedback
mechanism of autoregulation. mediated by cells in the macula densa which sense the change in NaCl delivery. this helps to regulate GFR.
functions of the kidney
regulate volume and composition adjusting excretion of water and electrolytes excretion of waste and metabolic breakdown products hormonal regulation EPO production Vitamin D metabolism renin angiotensin aldosterone axis regulation of low BP or blood volume
hormonal regulation-kidney function
metabolic degradation of peptide hormones such as pituitary hormones, glucagon, insulin
renin-angiotensin-aldosterone axis
renin is produced in JGA cells from prorenin. It is secreted into the afferent arteriole in response to various stimuli which cause renal hypoperfusion such as low BP, and decreased effective circulating volume.
Renin converts angiotensin 1->2 which causes:
systemic vasoconstriction (raising systemic BP) Na and water re absorption in PT which helps to restore volume Secretion of aldosterone
upper urinary tract symptoms of renal disease
flank pain or tenderness: renal infection, infarction, GN, rarely obstruction
Lower urinary tract infection symptoms
dysuria, frequency, urgency
bladder outflow obstruction symptoms
impaired urinary flow, hesitancy, dribbling, incomplete emptying of bladder
sphincter or bladder wall dysfunction symptoms
urinary retention, incontinence, enuresis
increased urine pH think:
infection with urea splitting organism
systemic alkalosis, renal tubular acidosis, carbonic anhydrase inhibitors
urinalysis finding of protein in urine
persistent indicates renal disease.
BUN
increases seen with *dietary intake (high protein) *high catabolic rate and tissue breakdown (hemorrhage, trauma, glucocorticoid therapy) *dehydration normal to low *muscle wasting and liver disease