Renal System Flashcards
Functions of the kidney
Excretion of metabolic wastes Regulation of water/lyte balance Regulation of osmolarity Regulation of arterial pressure Acid-base balance Erythrocyte production Influences Ca, Phos, Vit D metabolic pathways
Pathway of renal blood flow
afferent arterioles -> glomerular capillaries -> efferent arterioles -> peritubular capillaries -> venous capillaries
What is GFR?
volume of plasma filtered through glomerulus per minute
Function of renin
released when GFR is low to increase renal blood flow (by increasing BV, preload, CO, and BP)
Renin released from ______ cells.
juxtaglomerular
Define nephrotic syndrome and its effects
leakage of proteins from glomerulus
causes hypoproteinemia and massive proteinuria
What diseases can damage glomerular membrane and cause nephrotic syndrome?
DM, HTN, UTI, nephritis
How does afferent and efferent arteriole pressure influence GFR?
GFR increased with decreased afferent pressure and increased efferent pressure
How does sympathetic tone influence GFR?
constricts afferent arterioles and decreases GFR
What hormones of macula densa of kidney increase GFR? How?
Angiotensin II - constricts efferent
Prostaglandins - vasodilates afferent
How are creatinine and BUN levels used to determine renal function?
estimate GFR (but not as good as inulin); small rises indicate impairment or loss of nephron function
Renal function serum tests
creatinine, BUN, creatinine clearance
Compare/contrast acute and chronic renal failure
Acute - decrease in GFR, oliguria, reversible
Chronic - decrease in GFR, anuria (at end stage), irreversible
How to classify urine output?
< 400 ml/day = oliguria
no urine = anuria
3 types of acute renal failure based on location of damage.
- Renal hypoperfusion (before)
- Intrinsic acute renal failure (within glomerulus)
- Post renal failure (after)
