Renal Function Flashcards
Kidney function
Excretion of metabolic waste products Regulation of water and electrolyte balance Regulation of acid-base balance Regulation of arterial blood pressure Secretion of hormones
Patho of the kidney
Filtration
Reabsorption
Secretion
Excretion
Filtration
Diffusion of plasma molecules across the glomerular membrane. 20% of plasma in glomulerus is filtered into globular capsule
Reabsorption
Diffusion or active transport of molecules in the urine filtrate from the renal tubules to the peritubular capillaries. Molecules reabsorbed include sodium, water, and glucose
Secretion
Active transport of plasma molecules to the filtrate in the renal tubules. Molecules secreted include potassium and hydrogen
Excretion
Any filtered molecule that is not reabsorbed + the secreted molecules are excreted in the urine
Clinical measures of renal function
Volume of fluid filtered (per minute) by the glomeruli in the kidneys
Plasma creating
Normally 110% of filtered creatinine is excreted, therefore decreased GFR results in an increased in plasma creatinine levels
Creatinine clearance
Can be calculated based on 24 hour urine collections or estimated using urine and plasma creatinine levels
Plasma blood urea nitrogen (BUN)
A reflection of plasma urea levels
Decreased GFR results in an increased in plasma BUN levels
Kidney stones
Aggregarates of crystals, protein or other substance as in the urinary tract. Also known as renal calculus, urinary stones, or urolithiasis
Patho of kidney stones
Supersaturation of calcium in urine filtrate leads to precipitation of small calcium based crystals.
Once the Indus has formed, the supersaturated urine causes larger stones
Consequences of kidney stones
Urinary tract obstruction Acute pain Hematuria Hydronophrosis Chronic kidney disease
UTI
Inflammation of the bladder caused by infection, usually bacterial
Patho of a UTI
Bacterial contamination
Retrograde movement of bacteria from urethra to bladder
Inflammation leads to cystitis
Clinical manifestations of UTI
Asymptomatic Dysuria Frequency Suprapubic pain Fever Urinalysis
Complications of UTI
Acute pyelonephritis: upper ureter infection
Bacterium and sepsis: bacteria migrate into the bloodstream and cause a systemic inflammatory response
Acute glomerulonephritis
Acute inflammation of the globular membrane caused by an autoimmune response to untreated group A beta-hemolytic streptococcal infection
Primary etiology of Acute Glom
Untreated group A beta-hemolytic streptococcal infections
Can also lead to heart valve damage
Patho of Acute glom
Antibodies against strep cross react with the glomerular endothelial cells
Inflammatory response causes damage to the glomerular endothelium as neutrophils try to phagocytosis the immune complexes and antibodies
Clinical consequences and urinalysis findings in acute glom
Acute hemturia
Prteinuria
Oliguria
Nephrotic syndrome
Excretion of 3 g or more or protein urine output
Causes of NS
Glomerulonephritis Genetic mutations that cause alterations in the structure of the glomerular membrane Systemic diseases Drugs Infections
Patho of nephrotic syndrome
Increased glomerular membrane permeability to protein leads to proteinuria
Hypoalbuminemia: results in decreased plasma oncotic pressure which can cause systemic edema