Term
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Definition
| functional unit of kidney |
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Term
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Definition
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Term
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Definition
| cortical & juxtamedullary |
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Term
| functions of cortical nephron |
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Definition
removal of waste products
reabsorption of filtered nutrients |
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Term
| function/trait of juxtamedullary nephron |
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Definition
urine concentration
longer loops of Henle |
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Term
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Definition
renal blood flow
glomerular filtration
tubular reabsorption
tubular secretion |
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Term
| afferent arteriole/renal artery |
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Definition
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Term
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Definition
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Term
| renal blood flow (mL/min) |
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Definition
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Term
| renal plasma flow (mL/min) |
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Definition
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Term
| how much of blood = cells? |
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Definition
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Term
| how much of blood = plasma? |
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Definition
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Term
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Definition
tuft of 8 capillary lobes
located in Bowman's capsule
nonselective filtration
< 70,000 MW
cellular structure
hydrostatic & oncotic pressure
renin-angiotensin-aldosterone sys (RAAS) |
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Term
| kidney uses what to control hydrostatic & oncotic pressures? (it also affects filtration process) |
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Definition
| renin-angiostension-aldosterone sys (RAAS) |
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Term
| glomerulus - cell structure - # layers? |
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Definition
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Term
| 3 membranes of glomerulus |
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Definition
capillary wall
basement membrane
Bowman's capsule inner layer |
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Term
| glomerulus - capillary wall |
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Definition
endothelial cells w/pores (fenestrated)
large molecules & cells are blocked |
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Term
| glomerulus - basement membrane |
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Definition
| further restriction of large molecules |
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Term
| glomerulus - Bowman's capsule inner layer |
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Definition
intertwining podocytes
membrane-covered filtration slits |
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Term
| regulation of arteriole size for what? |
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Definition
| To maintain consistent glomerular pressure |
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Term
| glomerulus - low systemic blood pressure - results in what? prevents what? |
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Definition
| larger afferent & smaller efferent prevents decreased glomerular blood flow |
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Term
| glomerulus - high systemic blood pressure - results in what? prevents what? |
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Definition
| smaller afferent arteriole prevents overfiltration & glomerular damage |
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Term
| renin-angiotensin-aldosterone system (RAAS) does 2 things: ? |
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Definition
regulates blood flow
responds to blood pressure & plasma sodium changes |
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Term
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Definition
| macula densa b/c of bp changes |
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Term
| juxtaglomerular apparatus (2 parts) |
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Definition
juxtaglomerular cells - afferent arteriole
macula densa - efferent arteriole |
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Term
| good range of blood sodium |
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Definition
| 135-145 mg/dL (small range!) |
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Term
| RAAS cascade - see diagram |
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Definition
renin secreted by juxtaglomerular cells
angiotensinogen (inact.) - blood substance
angiotensin 1 - through lungs
angiotensin-converting enzyme (ACE) - in lungs, converts angiotensin 1 to 2
angiotensin 2 - releases aldosterone from adrenal cortex aldosterone & ADH from hypothalamus |
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Term
| angiotensin II functions (5) |
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Definition
dilates afferent arteriole
constricts efferent arteriole
stimulate Na reabsorption in proximal convoluted tubule (PCT)
aldosterone release
ADH release |
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Term
| aldosterone release causes what? (2) |
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Definition
reabsorption of Na in distal convoluted tubule (DCT) & collecting duct (CD)
increases potassium excretion (can cause elderly dementia) |
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Term
| ADH release causes what? (1) |
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Definition
water reabsorption in CD
(alcohol suppresses ADH) |
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Term
| tubular reabsorption - active transport - definition |
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Definition
| cellular energy & carrier proteins needed for transport back to blood |
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Term
| tubular reabsorption - actively transported (5) |
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Definition
glucose
salts (Na = highest)
amino acids in PCT
chloride in ascending loop of Henle
sodium in DCT |
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Term
| tubular reabsorption - passive transport - definition |
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Definition
| controlled by substance concentration gradients on sides of membrane |
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Term
| tubular reabsorption - passively transported (3) |
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Definition
water throughout, (accompanies high Na reabsorption in PCT), except ascending loop of Henle
urea in PCT & ascending loop of Henle
Na in ascending loop of Henle |
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Term
| What is maximal reabsorptive capacity (Tm)? |
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Definition
| plasma level at which active transport ceases |
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Term
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Definition
| plasma level causing active transport to cease |
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Term
| Where does normally reabsorbed substance appear if over threshold? |
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Definition
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Term
| What is glucose threshold? |
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Definition
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Term
| What does glucose in urine signify? |
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Definition
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Term
| Why is blood glucose better for diabetic screening? |
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Definition
| Glucose level has to be very high for dipstick to show it. |
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Term
| tubular concentration in descending loop of Henle |
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Definition
| passive reabsorption of water into highly concentrated medulla |
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Term
| tubular concentration in ascending loop of Henle |
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Definition
walls impermeable to water
analytes:
chloride (largest anion)actively reabsorbed
sodium (+) passively reabsorbed |
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Term
| What is countercurrent mechanism? |
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Definition
maintains concentration in medulla
medulla is diluted by H20 from descending;
reconcentrated by Na & Cl from filtrate in ascending |
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Term
| tubular concentration - DCT |
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Definition
| aldosterone-controlled Na reabsorption if needed by body |
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Term
| CD reabsorption - final filtrate concentration |
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Definition
| water reabsorption controlled by ADH in response to body hydration |
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Term
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Definition
| Amount of ADH produced by hypothalamus determines permeability of DCT and CT walls to water. |
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Term
| As body hydration increases, ADH & urine _? |
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Definition
ADH decreases
urine increases |
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Term
| As ADH increases, body hydration & urine _? |
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Definition
| Body hydration and urine decrease. |
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Term
| As urine decreases, body hydration & ADH _? |
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Definition
body hydration decreases
ADH increases |
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Term
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Definition
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Term
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Definition
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Term
| 2-pronged approach for eliminating waste |
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Definition
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Term
| elimination of nonfiltered wastes |
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Definition
protein-bound substances
regulation of acid-base balance
secrete H+ to return filtered buffers to blood
excretion of excess H+ ions |
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Term
| bicarbonate - what prevents excretion of HCO3-? |
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Definition
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Term
| Where is filtered bicarbonate returned to? |
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Definition
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Term
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Definition
| small H+ ions - may need to be excreted |
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Term
| What are excess H+ ions not needed to return filtered bicarbonate excreted as? |
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Definition
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Term
| Ammonia (NH3) is produced and secreted by what? |
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Definition
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Term
| H+ combines to form NH4+, which cannot be _. |
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Definition
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Term
| Additional ammonia is produced from the _ of _ in the PCT. |
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Definition
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Term
| Renal function tests evaluate what 4 things? |
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Definition
glomerular filtration rates
tubular reabsorption
tubular secretion
renal blood flow |
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Term
| glomerular filtration - clearance tests measure what? |
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Definition
| rate at which kidneys remove filterable substance from blood (can't be reabsorbed/secreted) |
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Term
| factors to consider in selecting clearance test substance (4) |
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Definition
stability of substance during timed urine collection
consistency of plasma level
accurately timed urine collection
availability of tests to measure substance |
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Term
| substances evaluated in clearance tests (6) |
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Definition
urea (earliest, no longer used, 40% reabsorbed, results adjusted for that)
INULIN
CREATININE
Beta2 microglobulin
cystatin C
radioisotopes |
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Term
| Inulin is a polymer of _. |
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Definition
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Term
| Can inulin be reabsorbed or secreted? |
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Definition
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Term
| What was the original clearance reference method? |
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Definition
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Term
| What is a disadvantage of inulin? |
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Definition
requires infusion:
exogenous procedure = infusion
endogenous procedure = body constituent |
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Term
| Is inulin a routinely used clearance test? |
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Definition
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Term
| What is the current routine test substance? |
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Definition
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Term
| What are advantages of creatinine clearance test? (2) |
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Definition
waste product of muscle destruction found at relatively constant plasma level
automated chemical tests |
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Term
| What are disadvantages of creatinine clearance? (5) |
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Definition
tubular secretion w/high blood levels
bacteria break creatinine down if urine's stored at room temp
heavy meat diet during timed collection increases urine creatinine
not reliable w/muscle-wasting diseases (MD)
gentamicin, cephalosporins, & cimetidine inhibit tubular secretion |
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Term
| What is the greatest error of creatinine procedure? |
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Definition
| improperly timed urine specimen |
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Term
| What is the principle of creatinine procedure? |
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Definition
| determine amount of creatinine completely removed from plasma during 1 min |
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Term
| What are units used to report creatinine? |
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Definition
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Term
| What is the creatinine removed in mL/min referred to as? |
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Definition
| glomerular filtration rate (GFR) |
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Term
| What are required measurements for creatinine test? |
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Definition
urine vol (mL/min)
urine creatinine (mg/dL)
plasma creatinine (mg/dL) |
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Term
| How do you calculate urine volume? |
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Definition
convert mL in specimen/min
24-hr specimen vol x 60 |
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Term
| What is normal urine volume? |
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Definition
| 1440 mL in 24 hours x 60 = 1 mL/min |
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Term
| What is the standard clearance formula? |
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Definition
C = UV/P or CP = UV
C = mL of plasma cleared per min
U = 100 mg/dL (urine creatinine)
V = 1 mL/min (urine volume)
P = mg/dL (plasma creatinine) |
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Term
| Put the standard clearance formula in words. C = UV/P |
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Definition
| If P is how much creatinine is in each certain vol of plasma, it is necessary to clear C volume of plasma to reach a urine concentration of U |
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Term
| For the standard clearance formula, the _ but not the amount of _ is reduced. |
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Definition
| volume but not the amount of creatinine |
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Term
| Creatinine is produced as a result of _ _. |
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Definition
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Term
| Normal values of creatinine are based on _. |
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Definition
| size - the larger the person, the more creatinine produced. |
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Term
| What's the normal creatinine value for men? |
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Definition
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Term
| What's the normal creatinine value for women? |
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Definition
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Term
| Creatinine values are _ in older people. |
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Definition
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Term
| _ are available to adjust creatinine levels for size. |
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Definition
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Term
| What are creatinine results based on? |
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Definition
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Term
| If needed, nephrons can _ their workload. |
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Definition
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Term
| Does creatinine detect early disease? |
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Definition
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Term
| Creatinine can monitor the extent of what? |
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Definition
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Term
| What can creatinine tests determine about meds? |
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Definition
| feasibility of administering medications that may build up to toxic blood levels |
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Term
| What can diabetes insipidus be caused by? |
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Definition
decreased ADH production
inability of tubules to respond to ADH |
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Term
| How can the cause of diabetes insipidus be determined? |
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Definition
After ADH injection, look at ratio of urine to serum -
1:1 ratio = no ADH receptors in CD
3:1 ratio = inability to produce ADH |
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