Body Fluids Flashcards
Intracellular fluids
25-30 L, in cytoplasm
extracellular fluid
15-20 L, blood and fluid outside of cell
componenets of ECF
plasma, interstitial fluid-fluid between cells, lymph, csf, eye fluids, synovial, serous, horone secretion
non-electrolyte
no charge, organic molecules, glucose, lipids, creatine, urea, covalently bonded
electrolytes
electrically charged, Na, K, Ca, Cl, inorganic acids bases, some proteins
measurement of electrolytes
milliequivalnets/liter=number of electrical charges
mEq/l
conc. of ion/atomic weight X electrical charges on one ion
extracellular fluids major cation
NA
extracellular fluid major anion
Cl
water intake
2.5 L per day, 60% from water, 30% from food, 10% from cells
water output
evaporation from lungs- 28%
prespiration-8%
feces-4%
urine- 60%
regulation of water
osomoreceptors, kidneys, body. temp, feces
what are salts in body fluids essential for?
neuromuscular excitability, secretin, membrane permeability, controlling fluid movement
how does salt exit the body
perspiration, feces, urine
role of sodium
90-95% in ECF
primary controller of ECF volume-osmosis
regulation of Na
PCT, loop of henle, DCT, collecting ducts, perspiration, ANP
PCT for Na
reabsorbs 65% of na in renal filtrate
loop of henle for Na
reclaims 25%, ascending
DCT and collecting ducts
reclaim remaining 10% only if aldosternone is present
ANP
promotes Na excretion dumped in urine, inhibts Na reabsorption, inhibits release of ADH, renin, aldosterone
regulation of potassium
kidneys, collecting ducts, aldosterone, adrenal cortex
potassium
major cation in cells
Role of K
membrane potential, electrical conduction in heart
kidney for K
85% is reabsorbed by nephron
15% lost in urine
collecting ducts for k
reabsorbed by type a intercalated cells
aldosterone for K
increases K secretin in coritical collection ducts
Calcium
99% of it is in the bones, needed for blood clotting, cell membrane permeability, muscle contraction, neurosecretion
regulation of Ca
PTH- decrease
calcitonin- increase
PTH
activates osteoclasts to break down and releas Ca in blood, increase intestinal absorption, increases reabsoprtionn in renal tubules
calcitonin
released by thyroid gland when blood ca increases, encourages bone deposition of ca
magnesium
2nd most abundant intracellular cation
purpose of magnesium
carb and protein metabolism, cardiac function, neurotransmission, neuromuscular activity, cofactor for ATP
where is Mg
50% is in bone
Chloride
helps Na maintain osmotic pressure, 99% of filtered Cl reabsorbed passively, in DCT Na and CL transport is coupled
Acid base balance
all biochemcial reactiona are influecned by the pH of body fluids
arterial blood pH
7.4
venous blood pH
7.35
H concentration in blood is regualted by
chemical buffer systems, respiration, kidneys
chemical buffer system
bicarbonate, phosphate, proteins
acids
proton donors
bases
proton acceptors
increase of H
increase of acicity, decrease pH
decrease of H
decrease of acidity, increase pH
buffers
solutions of weak acids and bases that resit changes in pH
bicarbonate
ECF buffer, ions are mopped up by HCO3 combining with H or H2CO3 splitting if H is low
HCO3 concentration is regulated by
kidneys
H2CO3 is regualted by
respiration
phosphate
in urine and ICF
increase of phosphate
H + HPO4 add
decrease of phosphate
H2Po4 splits to give up phosphate
proteins
most plentiful and powerful source o fbuffers in plasma and ICF
amino acids
mop up H, COO
give up H, NH3
respiratory regulation of Ph
physiological system, bicarbonate
respiratory acidosis
acid-base imbalance, respiration is insufficent, blood CO2 rises, pH falls
Respiratory Alkalosis
CO2 is elimiated faster than produced, respiration is too fast, pH rises
metaboloc acidosis
low blood HCO3 levels, too much alcholhol, ph Low
metabolic akalosis
less common , vomititng, blood HCO3 is high, pH is high
