Physiology Part 1 Flashcards
Total body weight is _______ nonwater mass and _____ total body water
40%, 60%
Total body water is _____ extracellular fluid and ______ intracellular fluid
1/3, 2/3
Extracellular fluid is _____ plasma volume and _____ interstitial volume
1/4, 3/4
What is the 60-40-20 rule?
60% TBW, 40% ICF, and 20% ECF
Plasma volume is measured by _____
radiolabeled albumin
Extracellular volume is measured by ______
inulin
Osmolarity is _____
290 mOsm/L
The GF barrier is responsible for filtration of plasma according to _____ and _______
size, net charge
The GF barrier is composed of____, _______, and _________
Fenestrated capillary endothelium
Fused GBM with heparan sulfate
Epithelial layer with podocyte food processes
Fenestrated capillary endothelium is the _______
size barrier
Fused GBM is the _________
negative charge barrier
_______ is lost in nephrotic syndrome
Charge barrier
What does nephrotic syndrome result in?
albuminuria
hypoproteinemia
generalized edema
hyperlipidemia
What is the renal clearance?
Volume of plasma from which the substance is completely cleared/time
What is the equation for Cx?
Cx=(UxV)/Px
What if Cx<GFR?
Net tubular reabsorption of X
What if Cx>GFR?
Net tubular secretion of X
What if Cx=GFR?
No net secretion or reabsorption of X
_______ can be used to calculate GFR because it is _________ and is neither _______ nor ________
Inulin clearance
freely filtered
reabsorbed
secreted
What is the equation for GFR?
GFR=Kf(Pgc-Pbs)-(PIEgc-PIEbs) where PIEbs is usually zero
Also UV/P because equals Cinulin
What is the normal GFR?
100mL/min
______ is an approximate measure of GFR.
Creatinine clearance
Creatinine clearance slightly _________ GFR because creatinine is moderately _________ by the renal tubules
overestimates
secreted
Incremental reductions in GFR define what?
The stages of CKD
Effective Renal Plasma Flow (ERPF) can be estimated using ______ because it is both ______ and actively _______ in the _______.
PAH clearance
Filtered
Actively secreted
Proximal tubule
All PAH that enters the kidney is ________
Excreted
What is the equation for RBF?
RBF=RPF/(1-Hct)
ERPF underestimates RPF by ______
about 10%
ERPF equation?
ERPF=UV/P=Cpah
FF=
FF=GFR/RPF
FF is noramlly….
20%
Filtered Load=
FL=(GFR)X(Px)
GFR can be estimated with _________
Creatinine Clearance
RPF can be estimated with ___________
PAH Clearance
Prostaglandins _______
Dilate afferent arteriole
Prostaglandins ___ RPF, ____ GFR, and FF _____
Increase
Increase
Constant
What inhibits prostaglandins?
NSAIDs
AngII ________
Preferentially constricts efferent arteriole
AngII ______ RPF, ________ GFR, and FF_______
Decrease
Increase
Increase
Afferent Arteriole Constriction ____ RPF, ____ GFR, _____ FF
Decrease
Decrease
No Change
Efferent Arteriole Constriction ____ RPF, _____ GFR, ______ FF
Decrease
Increase
Increase
Increased plasma protein Concentration ____ RPF, ______ GFR, _________ FF
No Change
Decrease
Decrease
Decreased plasma protein concentration ___RPF, _____ GFR, ______ FF
No Change
Increase GFR
Increased FF
Constriction of ureter _____ RPF, ______ GFR, ____ FF
No change
Decreases
Decreases
Excretion Rate=
(V)X(Ux)
Reabsorption=
Filtered-Excreted
Secretion=
Excreted-Filtered
Glucose at normal plasma level is ______ reabsorbed in _________ by _________.
Completely
Proximal tubule
Na/Glucose cotransporter
Glucosuria (threshold) begins at _______
160 mg/dL
All transporters are fully saturated (Tm) at _____
350 mg/dL
Glucosuria is an important clinical clue to ______
Diabetes Mellitus
Normal pregnancy reduces reabsorption of ______ and _____ in the _______.
Glucose
Amino Acids
Proximal tubule
Normal pregnancy leads to ______ and _______
Glucosuria
Aminoaciduria
Amino Acids are cleared by ____________ in the ________
Sodium dependent transporters
Proximal tubule
What is Hartnup’s disease?
Deficiency in neutral amino acids (trytophan) transporter
What does Hartnup’s disease result in?
Pellagra
What blocks AngII?
ACE Inhibitor
Early PT contains _____
Brush Border
What does the early PT reabsorb all of?
Glucose and Amino acids
What does early PT reabsorb most of?
Bicarbonate Sodium Chloride Phosphate Water
PT results in ______ absorption
Isotonic
PT generates and secretes _____, which acts as what?
Ammonia
Buffer for secreted H+
In the PT, PTH inhibits _________
Na/Phosphate cotransporter
In the PT, PTH results in what?
Phosphate excretion
In the PT, ATII stimulates _________
Na/H exchange
In the PT, ATII results in what?
Increased Na, H20, and HCO3 reabsorption
In the PT, ATII permits what?
Contraction alkalosis (increase in blood pH as a results of fluid loss)
How much of Na is reabsorbed in the PT?
60-80%
Thin Desc. LOH _____ reabsorbs water via __________, because it is _______ to sodium.
passively
medullary hypertonicity
impermeable to sodium
Thin Desc. LOH can be described as the _______ segment as it makes urine _______.
Concentrating
Hypertonic
Thick Asc. LOH actively reabsorbs _______
Na
K
Cl
Thic Asc. LOH induces paracellular reabsorption of ____ through _________ generated by _______.
Mg, Ca
Positive lumen potential
K backleak
Thick Asc. LOH is _______ to water
impermeable
Thick Asc. LOH makes urine ________ as it ascends
Dilute
How much of Na is reabsorbed in the Thick Asc. LOH?
10-20%
Early Distal Convoluted tubule actively reabsorbs ________
Na
Cl
Early Distal Convoluted tubule makes urine _____tonic
hypo
PTH does what in the early distal convoluted tubule?
Increases Ca/Na exchange
PTH leads to what in the early distal convoluted tubule?
Ca reabsorption
How much Na is reabsorbed in the early distal convoluted tubule?
5-10%
Collecting Tubules reabsorb _____ in exchange for secreting _____ and ______. This is regulated by ______.
Na
K, H
Aldosterone
Aldosterone in the collecting tubules acts on ______ receptor and leads to _______.
Mineralocorticoid receptor
Insertion of Na channel on luminal side
ADH in the collecting tubules acts at _____ receptor and leads to _____.
V2
insertion of Aquaporin water channels on luminal side
How much Na is reabsorbed in the collecting tubules?
3-5%
