Phys 25-32: Kidney make pee Flashcards
Evaporation loss of water from skin/respiratory tract per day
700ml
Intracellular fluid weight percent of body
Extracellular fluid weight percent of body
ICF 40%
ECF 20%
Lymphedema parasite
Wucheria Bancrofti
In advanced heart failure, increased secretion of _______ stimulates _______by the renal tubules, leading to _______
In advanced heart failure, increased secretion of ADH stimulates water reabsorption by the renal tubules, leading to hyponatremia and edema
What substance is used to create spacing between renal tubule cells
Proteoglycan filaments
Hypoxia stimulates kidney to secrete
Erythropoetin
Calcitriol aka
1,25-dihydroxyvitamin D3
Normal kidney blood flow per min
1100 ml
Smooth muscle of bladder aka
Detrusor
Max bladder pressure
40-60mmhg
Bladder sympathetics
L2 hypogastric nerves
Bladder parasympathetics
Sacral plexus S2/S3
Micturition facilitation and inhibition centers where
Brainstem, mostsly pons
Some in cerebral cortex
Cause of uninhibited neurogenic bladder
Damage to spinal cord means no brain inhibition of micturion reflex
Charge effect on filterability of substance in nephron
Postive charge filters more readily
Filtration coefficient equation
Kf = GFR/ filtration pressure
Increased bowmans hydrostatic pressure does ____ to GFR
Decreases
Increased glomerular colloid osmotic pressure does what to GFR
Decreases
Increased glomerular hydrostatic pressure does what to GFR
Increases
Renal blood flow equation
RBF = (Renal artery pressure - Renal vein pressure) / (renal vascular resistance)
Angiotensin and GFR
Prevents it from coming down, doesnt change it significantly
Sympathetic stim effect on GFR
Decreases
Endothelial-Derived nitric oxide ______ Renal Vascular Resistance and ______ Glomerular Filtration Rate
Increases
Decreases
NSAIDs and GFR
prostaglandins inhibitted, no efferent arteriole constriction
GFR down
Juxtaglomerular cells where
Walls of efferent/afferent arterioles
Macula densa response to sodium changes (2)
When sodium is decreased, macula densa decreases glomerular pressure, increasing GFR.
When sodium is decreased, macula densa signals juxtoglomerular cells to release renin
Protein ingestion and GFR
Increases GFR.
Increased protein reabsorption = increased sodium reabsorption. This causes macula densa to increase GFR
GFR and age
Low at birth, reaches adult levels at 2yo. At 40 begins decreasing 5-10% per decade
Glucose reabsorption location and transporter
Early proximal tubule
SGLT2
Protein reabsorption mechanism
Pinocytosis
% of sodium reabsorption in proximal tubule
65%
Site of secretion of organic acids and bases
Proximal tubule
Compound used to estimate renal plasma flow
PAH para-aminohippuric acid
thick ascending loop sodium transport by
NKCC2 co transporter.
Two types of cells in distal tubule
Principal cells
Intercalated cells
Principal cells reabsorb _______ and secrete _____
Reabsorb water and sodium
Secrete potassium
Intercalated cells reabsorb ___ and secrete _____
Potassium
Hydrogen ion
how does type A principal cell secrete potassium
Na+/K+ ATPase in basolateral membrane creates gradient.
K+ diffuses to lumen bc of gradient
Cell affected by potassium sparers
Principal cells (blocking sodium entry means no potassium efflux to lumen)
Type A vs B intercalated cells
Type A: Secretes hydrogen into lumen
Type B: Secretes bicarb into lumen
Type B cells main transporter into lumen
Pendrin Cl-/HCO3- counter transporter
Urine is most dilute whre
Right at the end of the loop of henle
Permeability of collecting duct to water is controlled by
ADH
Substance used to calculate water reabsorption
Inulin (doesnt get reabsorbed)
Aldosteron acts on _____ (kidney)
Principal cells in collecting tube
aldosterone increases _____ reabsorption and ______ secretion is by stimulating _____ on the ______ side of the ______ membrane
aldosterone increases sodium reabsorption and potassium secretion is by stimulating the Na+-K+ ATPase pump on the basolateral side of the cortical collecting tubule membrane
Aldosterone defficiency lab values (serum)
Sodium goes down (lost in urine)
Potassium goes up (can’t secrete)
Parathyroid hormone tubular absorption effect
Decreases PO4- reabsorption
Increases Ca2+ reabsorption
ADH binds to ____, stimulating _______ movement to lumen
V2
AQP-2
Angiotensin II stimulates reabsorption of
Sodium, H20, H+
Atrial Natriuretic Peptide reabsorption effects
Decreases sodium and water
Sympathetic nervous system _____ sodium reabsorption
Increases
Also renin release
ADH released by ____ in response to _____
Posterior pituitary
increased osmolarity
Max daily urine excretion of water
20 liters
Tubular fluid in proximal tubules is ____osmotic
Isosmotic
Part of nephron where fluid is most concentrated
Bottom of loop of henle
Fluid leaving distal tubular segment is ___osmotic
Hyposmotic
Max urine concentration
1200-1400 mOsm/L
Maximum urine NaCl excretion
600 mOsm/L
Two requirements to make concentrated urine
1) High ADH level
2) High osmolarity renal medullary fluid
Osmolarity of medullary fluid
Increases progressively up to 1400 mOsm/L
Urea contributes to % of urine osmolarity
40-50%
Passice secretion of urea into thin loops off henle is facilitated by
Urea transporter UT-A2
Concentration of urea in tubular fluid in inner medullary collecting duct facilitated by
UT-A1 and UT-A3
What prevents medullary hypersmolarity from being disapated
The Vasa recta
Increased medullary blood flow ____ urine concentration abilty
Decreases
Water diffusion across tubular epithelium is aidead by
Aquaporin 1
How to calculate osmolar clearance
(Urine Osmolarity x Volume) / (Plasma osmolarity)
How to calculate free water osmolarity
= (Urine volume) - (Urine volume)
Central diabetes insipiduse caused by
Failure to secrete ADH
Nephrogenic diabetes insipidus caused by
Kidneys fail to respond to ADH
Estimation of plasma osmolariy from plasma sodium formula
Plasma Osmolarity = 2.1 x Plasma sodium
ADH release steps
1) Increased plasma OSM causes osmoreceptor cells in anterior hypothalmus to shrink
2) Shrinkage of osmoreceptor cells causes them to fire
3) Action potentials are conducted to posterior pituitatry, which stimulates ADH release
Lesions in ___ brain region cause defecits of ADH secretion
AV3V region
Drugs that increase ADH release
Morphine
Nicotine
Cyclosphimide
Drugs that inhibit ADH release
Alcohol
Clonidine
Haldol
Nausea and ADH secretion
Nausea is a potent ADH release stimulus
Thirst mechanism activated at ___ (threshold)
Sodiun concentration 2mEq/l above normal
Angiotensin II and aldosterone effect on sodium concentration
Minimal
Cell potassium uptake after a meal is mediated by
Insulin
Alkalosis/Acidosis and potassium shift
Alkalosis pushes K+ into cells
Acidosis pulls out K+ from cells
Potassium secretion occurs in _____ cells of _____
Principal cells of late distal and cortical collecting tubules
Secretion of potassium in principal cell steps
1) K+ passively diffuses from blood to renal interstitium
2) K+ actively transported into principal cells by Na/K ATPase
3) K+ passively diffuses into urine
Type A intercalated cell vs Type B intercalated cells (potassium)
Type A: Reabsorb potassium
Type B: Secrete potassium
How does acidosis increase K+ extracellularly
Inhibits Na/K ATPase
PTH 3 main effects
1) Stimulates bone resoprtion
2) Stimulates Vitamin D activation
3)increases renal tubular calcium reabsorption
PTH acts at ______ to _____ calcium
Ascending loop of henle
Reabsorb
Calcium reabsorption and acid/base
Acidosis: reabsorption increased
Alkalosis: Reabsorption inhibited
Acidosis ______ potassium secretion by kidney
Decreases
Most important acid/base buffer in body (intracellular and extracellular
Intracelullar: Cell proteins
Extra cellular: bicarb
Bicarb equation
Increased hydrogen Ion concentration in blood stimulates _____ (breathing)
Pulmonary ventilation
In late distal and collecting tubules, H+ is secreted via
Primary active tranport
Urinary ____ carries excessive H+ into urine and generates new _____
Phosphate
Bicarb
Most important urinary buffer in chronic acidosis
Ammonia
Renal glutamine metabolism is stimulated by ____
Acidosis
How does glutamine metabolism help with acidosis
It is metabolized to NH4+ and HCO3-. NH4 is secreted, HCO3- is reabsorbed into blood
Net acid excretion rate calculation
Hydrogen secretion calculation
Renal tubular H+ secretion is stumulated by increases in:
Extracellular H+
Increased PCO2