what is the functional unit of the kidney?
nephron: bowmans cap, prox conv tube, loop og hen, distal tube, collecting duct
the spontaneous mvmnt of fluid from area of higher concentration to lower is?
Diffusion
where does the concentration and dilution of urine occur?
juxtamedullary nephrons
the function of aldosterone is primarily?
control Na and H2O
when renin is released the physiologic effect is?
vasoconstriction
when hypotension occurs, which helps mntn adequate glomerular pressure?
constrict efferent arteriole
the beginning of filtration at each nephron occurs at the?
glomerulus
what will result in increased release of renin?
reduced pressure in glomerulus
after angio 1 to angio 2, the adrenal glans are stimulated to secrete?
aldosterone
increased secretion of ADH =
increased resorption of H2O in collecting duct
GFR is influenced by
blood flow through the glomerulus (rate)
what things would decreased the GFR?
low BP,
obstruction of flow of filtrate in the tubules,
low plasma oncotic pressure
the best indicator of glomerular filtration rate (and therefore function) is?
creatinine clearance test
what % of bicarb is reabsorbed from the filtrate?
90%
in the presence of renal ischemia or injury, what might occur
metabolic acidosis
if the loop of henle was damaged, what would you see
dilute urine
the functions of the proximal con tubule include?
- resorption of H2O, Na, K, Cl, HCO3, amino acids and urea
the main function of the collecting duct include?
- H2O resorption in the presence of ADH
- resorption/ secretion of H+ ions and HCO3
- concentration of urine by resorption of H2O by water osmosis
how do the kidneys respond to low perfusion
-RAAS activation by juxtaglomerular apparatus
decreased perfusion to kidneys = RASS active = angio 1- angio 2 (in lungs).
- angio 2 - potent vasoconstrict (constricts efferent arterioles)= increase afterload and increases BP
- angio 2 stimulates adrenal gland to release aldosterone = retains Na and H20
5 major renal fnctn
- fluid and electrolyte balance
- acid-base balance
- metabolic waste excretion
- bp regulation
- endocrine reg (erythropoietin, vit D)
risk factors AKI
- sepsis
- nephrotoxic drugs: mycin’s, penicillins, cyclosporins, corticosteriods, lasix, contrast dye
- other drugs: NSAIDS, ACE-inhibit
- intra- abd compression
- rhabdomylosis- myoglobin from skeletal muscle inj
Physical assess includes
- visual flank/abd
- preload: JVD, skin turgor, mucus membranes, edema, dypnea
- auscultate: extra heart sounds, crackles
vol status
R I F L E
risk injury failure loss end stage
creatinine
- *most reliable**
- biproduct of muscle metabolism
- filtered by glomerulus (intrarenal)**, not reabsorbed
- caused by: kidney failure due to impaired excretion, catabolic states (excess training with poor nutrition)
