Na,K, Cl Flashcards
How can water be lost from the body?
insensible loss, sweat, feces, urine = 2.5L/day
Other: infections, malabsorption
How would the kidneys respond to large amounts of water?
this would cause a decrease in solutes and osmotic gradients - water will flow into cells where osmotic conc is higher - kidney will quicky excrete water to compensate - increased urine volume
How would the kidneys respond to large quantity of salt
increase plasma osmotic gradient - cells shrink - kidneys excrete more solutes
What is normal osmotic movement in and out of the kidneys
300 mOsm
Different b/w descending and ascending limp of kidneys
D: permeable to water
A: permeable to ions, and solute, water, has Na:K pumps
Proximal tubule
Filters 100%. reabsorbs up to 65%, permeable to water, salts, bicarbonate, glucose, AA, creatinine, urea
ADH / Vasopression
hormone for renal control of water reabsorption via AQP2
- Distal tubule and collecting ducts
Aldosterone
Reabsorption of Na+ via Na/K exchange.
RAA for vasoconstriction = increased BP
- K excreted, Na+ retained + water
-distal tubule and collecting ducts
ADH action through the cell
Binds receptor
AQP2 apical transcription apical `
Accept water
Leave Via AQP3 basolateral
Aldosterone action through the cell
Increases luminal Na+ channels & Na/K pumps basolateral
influx of sodium into the cell and increase in pump then increase sodium into plasma - water follows, stimulates thirst
Difference between a salt deficit and a excess water loss
Salt deficit will increase Sympathetic activity, decrease GFR, increase aldosterone and ADH
Water loss will increase plasma osmolarity, stimulate ADH & thirst
ANP - Atrial Antidiuretic hormone
response to increased BP, acts on efferent and afferent arteriole, and DCT,
- Vasodilation + inhibits Na uptake
ANG II
Response to hypotension on afferent and efferent arterioles.
Vasoconstriction + Na absorption
Describe kidney functions and what occurs with CKD in regards to those functions
Sodium balance —> Na retention and volume overload
K+ excretion —> Hyperkalemia
Acid excretion —> Metabolic acidosis - decrease H+ availability
Ca/P balance —> Increase phosphate and decrease calcium
Erythropoiesis —> Anemia
What would cause excessive Na and Cl retention??
Sea water and fast infusion of saline
Hypersecretion of Aldosterone (Crushers syndrome = decrease K, increase PH + BP)
Congestive heart failure (body thinks it needs salt to increase heart rate)
Hypernatremia ([Na+] > 145mmol/L) due to decrease in TB water relative to Na+
Failure of kidney control
What would cause a deficiency in Na and Cl-
Water > Solute
hypernatremia (hypervolemia, hypovolemia, euvolemia)
too much water during sports
non-renal loses + renal loses (ex. vomit, diarrhea – diuretics, diabetes)
Fluid volume sodium symptoms association effects?
BP and CNS function
difference + Similarity b/w hypo/hyper kalemia
hypo - < 3.5mmol, increased K+ excretion, hyperpolarize, inadequate intake, extra to intracellular shift
Hyper - >5.5 mmol, combo of excessive increase intake and decreased excretion, hypopolarize , intra to extracellular shift
both: affect muscle contractions or cardiac function
All potassium symptoms associated with
nerve transmission and muscle contraction
AI and UL for salt
3.8g/day AI
6g /day UL
(Note salt is 40% sodium)
What is the na intake associated with High BP
2.3g/day
What is the min Daily intake recommended for salt
500mg na, 750mg cl
why does the food industry industry rely on salt
Color developer , Fermentation, Binder, Texture aid, Preservative
What is the potassium AI and recommended intake
4.7g/day AI
2g/d recommended
Food sources of potassium
plum, banana, plantains, melon, raisins, OJ, milk, plain yogurt
Describe the range of values of Na, K, & Cl inside and outside of cells
Na - outside: 135-148 mmol/L. Inside: 12 mmol/L
Cl - outside: 98-108 mmol/L. Inside: 2 mmol/L
K - outside: 3.8-5.5 mmol/L. Inside: 150 mmol/L
What controls electrolyte disturbances and balance in the body
Movement of ions: passive and active
Selective permeability: prevents movement of proteins and phosphates
describe fluid distribution and body compartments
Extracellular fluid: all fluid outside cell, including fluid in blood and plasma. Also contains interstitial fluid between cells and outside BV
35% - 25% is interstitial fluid
Intracellular fluid - all fluid inside cells - 65%
Electrical gradient
overall charge / overall neg charge - adding ions
outflow of more Na+ than inflow of K+
(3 Na+, 2K+ in)
Chemical gradient
simply the molecule:
extracellular Na vs cytoplasm
Main fxn of Na/K
Maintains ionic homeostatsis, regulates cell volume, basis for water soluble absorption
What is the purpose active absorption of Na+
primary mechanism for passively absorbing draws Cl- ions, monosaccarides, AA, water
What is the importance of the asymmetric distribution of channels/pumps
these pumps promote Na+ to pumped out and K IN
generates a gradient from luminal side intracellularly - allows transport of molecules in free of charge
What allows Na+ to be 95% - 100% absorbed
Gradient created by Na, K-ATPase pump
Na+/glucose co-transport, Na/H exchange, Na/Cl co-transport
What allows K+ to be 85-90% absorbed
via colon by passive diffusion or H+/K+ pump
Aldosterone can cause a shift
What organs play the biggest role in electrolyte balance
Kidneys
Intestine (mnor)
which will cause faster depolarization hyperkalemia or hypokalemia
hyperkalemia causes faster depolarization: muscle spasm
Hypokalemia causes hyperpolarization (really low membrane reset) because of a bigger electrochemical difference: decrease muscle contraction
