Renal Flashcards
What is the functional unit of the kidney?
nephron
Function of kidney
filter blood of toxins/wastes and reabsorb needed molecules
What are the vascular components of the kidney?
glomerulus and peritubular capillaries
What are the tubular component of the kidney?
proximal convoluted tubule, loop of henle, distal convoluted tubule, collecting tubule
What maintains the concentration gradient?
Na+/K+ ATPase
Symport
2 molecules move across a membrane by carrier
Antiport
2 different molecules move across membrane by common carrier
Exchange
change places of molecules
What is urea
formed in liver as byproduct of protein
Elimination function of kidneys
renal clearance, regulation of sodium and electrolytes, uric acid elimination, urea elimination, drug elimination, pH dependent elimination of organic ions
Prerenal
related to perfusion (volume), related to heart failure
Postrenal
obstruction of urine flow
Function on nephron
reabsorption of water, electrolytes, and other substances from the bloodstream
RAAS system role
regulation of blood pressure and fluid electrolyte balance
Juxtaglomerular complex role
feedback system linking GFR with renal blood flow
Erythropoietin function
regulates the differentiation of red blood cells in bone marrow, stimulates RBC formation
Vitamin D function
increases calcium reabsorption from the gastrointestinal system, helps regulate calcium deposition in bone
Loop diuretics
exert their effect in the thick ascending loop of Henle (might give to someone with edema, heart failure, hypertension)
Thiazide diuretics
prevent the reabsorption of NaCl in the distal convoluted tubule (can be used for high BP)
Aldosterone Antagonists (K+ sparing diuretics)
reduce sodium reabsorption and increase potassium secretion in the late distal tubule and cortical collecting tubule site regulated by aldosterone (can treat high BP and heart failure)
Characteristics of normal urine
clear, yellow fluid, 95% water and 5% dissolved solids, normally produce 1.5 L of urine each day, contains metabolic waste and few to no plasma proteins, blood cells, or glucose molecules
Urine specific gravity tells what
provides valuable index of hydration status and functional ability of the kidneys; healthy kidneys have specific gravity of 1.030-1.040
Renal clearance
volume of plasma that is completely cleared each minute of any substance that finds its way into the urine
Determining factors of renal clearance
ability of substance to be filtered in glomeruli, capacity of the renal tubules to reabsorb or secrete the substance
Tests for renal function
urinalysis, GFR, blood tests (serum creatinine, BUN), cystoscopy, ultrasound, radiologic images
What does increase in BUN and serum creatinine say about a person
increase in BUN and serum creatinine indicate renal failure
Where is EPO (erythropoietin) produced?
kidney
What factors affect GFR
glomerular capillary hydrostatic pressure, glomerular capillary osmotic pressure, hydrostatic and osmotic pressure in Bowman capsule
what do serum creatinine levels indicate?
calculating GFR and estimating functional capacity of kidneys
If serum creatinine doubles what does that say about GFR and renal function?
fallen 1/2 normal state
If serum creatinine triples what does that say about GFR and renal function?
75% loss of renal function
If serum creatinine >10 mg/dL or more what does that say about GFR and renal function?
90% renal function loss
What is the most common defect of kidney?
anomalies in shape and position
agenesis of kidney
kidney doesn’t develop
Hypogenesis of kidney
underdeveloped kidney
UTI can cause intra, post, or prerenal injury?
Intrarenal injury
Potter syndrome
no kidneys or kidneys that don’t work
Cystic disease of the kidney
fluid filled sacs or segments of a dilated nephron
Causes of cystic disease of kidney
tubular obstructions that increase intratubular pressure or changes in basement membrane of renal tubules that predispose to cystic dilation
Types of cystic disease of kidney
simple and acquired renal cysts, medullary cystic disease, polycystic kidney disease
Causes of UTI
kidney stones, developmental defects, pregnancy, prostatic hyperplasia, scar tissue, tumors, neurologic disorders (spinal cord injury), stasis of urine
Kidney stones
crystalline structures that form from components of the urine
What is required for a kidney stone to form
a nidus (nest), urinary environment that supports continued crystallization of stone components
Preventative treatments for kidney stones
dietary restriction, calcium salt supplementation, thiazide diuretics, cellulose phosphate
Types of UTI
asymptomatic bacteriuria, symptomatic infections, lower UTI (cystitis), upper UTI (pyelonephritis)
Causes of UTI
most are caused by escherichia coli,staphylococcus saphrophyticus, gram negative rods, gram positive cocci
Protective mechanisms for UTI
washout phenomenon, mucin layer, local immune responses, normal flora in women, prostate secretions in men
What condition doesn’t lead to stone formation?
high Na+ concentration
Glomerulonephritis is
inflammation of glomeruli
Immune mechanisms for glomerulonephritis
glomerular antibodies, circulating antigen-antibody complex
Characteristics of glomerularnephritis
hematuria (blood in urine), low GFR, azotemia (nitrogenous waste in blood), oliguria (barely pee), hypertension
causes of glomerulonephritis
damage to capillary wall, permits RBC to escape into urine, produces hemodynamic changes that decrease GFR
Renal neoplasms (cancer) in children
Wilms tumor, onset at 3-5 yrs, in one or both kidneys, WT1 mutation on chromosome 11
Adult kidney cancer
renal cell carcinoma
renal failure
condition in which kidneys fail to remove metabolic end products from the blood and regulate fluid, electrolyte, and pH balance of extracellular fluids
Acute renal failure
abrupt in onset, often reversible
chronic renal failure
irreversible damage, develops slowly
Prerenal causes of acute renal failure
hypovolemia, decreased vascular filling, heart failure, decreased renal perfusion
Think about it as a perfusion issue (volume) and heart failure
Postrenal causes of acute renal failure
bilateral ureteral obstruction, bladder outlet obstruction
intrarenal causes of acute renal failure
acute tubular necrosis, exposure to nephrotoxic drugs, intratubular obstruction, acute renal disease, UTI
Phases of acute tubular necrosis
onset/initiating phase: time from onset of precipitating event until tubular injury occurs
Maintenance phase: decrease in GFR
Recovery phase: repair of renal tissue takes place
common causes of chronic renal disease
hypertension, diabetes mellitus, polycystic kidney disease, obstruction of urinary tract, glomerulonephritis, cancer, autoimmune disorder, disease of lung or heart, chronic use of pain medication
what number would represent a mild reduction of GFR
60-89 ml/min
what number would represent a moderate reduction of GFR
30-59 ml/min
what number would represent a severe reduction of GFR
15-29 ml/min
what number would represent a kidney failure with a GFR
<15 ml/min
What is gaut
buildup of uric acid
Hematologic disorders of renal failure
anemia (low EPO) and coagulopathies (clotting disorders)
cardiovascular disorders of renal failure
hypertension, heart disease, pericarditis
treatment of renal failure
dialysis (hemodialysis or peritoneal dialysis), transplant, dietary management
what can affect drug efficacy in a patient with CKD
loss of albumin
