What percent of fluids in humans are Intracellular fluid?
What perecent of ECF is interstitial fluid?
What are the 3 sources of water intake?
Food (700 ml), Drinks (1600 ml) and Metabolic water (200 ml)
What is metabolic water?
produced by doy from aerobic cellular respiration/ dehyration synthesis reactions
What are the 4 ways we lose water?
GI (100 ml)
skin (600 ml)
kidneys (1500 ml)
Where in in the brain is the thirst center?
What are the 3 most hormones that regulate renal Na+/ Cl- loss?
Angiotensin II, aldosterone, ANP
Which is the only hormone that increases water loss in urine?
Name 1 mechanism causing water loss from these systems
2) vomiting/ diarrhea
Which hormone promotes reabsorption of Na+ and Cl-, and which one promotes excretion?
What do oral rehydration therapy need to add some NaCl?
Otherwise, low Na+ = hyponatremia --> low osmolarity of interstitial fluid/plasma--> water into cells, swelling = convulsions, coma, death
Name the most abundance extracellular cation and anion
Na+ and Cl-
Name the most abundance intracellular cation and anion
K+ and HPO4
What's the normal plasma conc of Cl
Which hormone controls plasma K+ concentration?
What is the 2nd most prevalent extracellular anion?
What is normal bicarb plasma concentration?
What 3 ways do PTH increase serum Ca?
: stimulate osteoclasts
: reasbosrb Ca
3) gut: increased calcitriol = increased absorption
What does PTH do to PO4 in
1) the bone
2) the kidney
3) the gut
: increase by stimulating osteoclasts
: decrease by inhibiting reabsorption
: increase by increased absorption
What is the top 2 intracellular cations?
1) K+ and Mg++
What is normal serum level of Mg?
What percentage of an infant's water (<2 yo) is ECF?
2/3-opposite of adults, so rapid losses more serious
What is percent of normal saline?