What is the average water content?
60%, 42 L
How does the avg water content differ in females?
More body fat, less water
What are the fluid compartments?
how the percentage of total body water is distributed
Composition of plasma differ from interstitial fluid?
Wall of capillary separates, proteins higher in plasma ions
How does composition of ECF differ from ICF
ECF more NA, ICF more K
Major cation & anion of ICF
Major cation & anion of ECF
What forces water to move between components?
driven by changes in hydrostatic pressure & osmotic pressure
Fluid exchanges in capillary bed
higher hydrostatic pressure than interstitial fluid, pushes fluid out of vessels into interstitial fluid
water moves to where more particles are
If an individual takes in water
Plasma dilutes, hypotonic-water moves into cells
If an individual is dehydrated
Plasma is more concentrated, hypertonic-water moves into vessel
Sensible water loss
Noticeable ex. Urine, feces
Insensible water loss
not noticeable, transpiration in skin, lungs
Which type of water loss is most readily controlled to help balance h20 homeostasis?
What ways body gains water?
food, squids, metabolic h2o
Where is thirst center?
What type of receptor and stimulus
Osmo receptor, Increased osmo
What other stimuli
Decreased plasma volume, decreased saliva, angiotensin 2
What is necessary to form concentrated urine?
ADH countercurrent mechanism to set up osmotic gradient, need juxtamedularry nephrons
Fluid regulating hormone
ANP- looses h2o
Causes of dehydration
impaired renal function
loss of h2o & solutes
retention h20 & solutes
causes of edema
Decrease plasma oncotic pressure
^ capillary permeable
What are electrolytes
salts that dissociate into ions in solution
What hormones regulate sodium?
Aldosterone says retain Na, Angiotensin 2 retain, ANP loose Na
excessive water and no electrolytes
What hormone regulates K
Aldosterone retain K, loose NA
What other things can influence the distribution of K
Insulin, aldosterone and epic can stimulate movement of K into cells
renal failure, acidosis
What hormone regulates Calcium (and phosphate)
PTH & calcitrol