Lec 3 Physiology basics Flashcards
How do you calculate mMol/L?
mg of substance / formula weight / Liters
- tells you how many particles per L solution
How do you calculate mEq/L?
mMol/L * valence * # of molec
- tells you ionic charge of solution
How do you calculate mOsm/L?
mMol/L * number of particles
- tells you how many total particle to help figure out osmotic pressure
How do you calculate % solutions?
grams of substance per 100 mL
What is total body fluid volume?
40 Liters
What is extracellular and intracellular volume?
- 15 L extracellular
- 25 L intracellular
What is blood volume?
5 L
What percent of fluid volume is extracellular/intracellular?
extracellular = 1/3 of total fluid intracellular = 2/3 of total fluid
What percent of body weight is blood volume?
8% of body weight
What percent of body weight is water?
60%
What is normal osmolality?
300
What is normal extracellular pH?
7.37-7.42
What is major cation in extracellular space?
Na
What is major cation in intracellular space?
K
What are major anions in extracellular?
Cl, HCO3
What are major anions in intracellular?
primary anions are actually intracellular proteins
How does urine output change in different conditions?
changes to offset differences in sweat/feces/lung/etc in order to maintain water balance
What is the definition of osmotic pressure?
pressure needed to offset fluid movement based on osmosis
What characteristics make a certain particle an osmotic particle?
- solute needs to be dissolved [can’t be suspended]
2. has to be trapped on one side of a membrane
Does size or number of particles matter in osmotic pressure?
number of particles, not size
How many mmHg is 1 mOsm/L?
19.3
3 principles of water shift between body fluid compartments
- volume of compartment is determine by amount of solute it has
- water follows salt
- the body does not tolerate osmotic imbalances
Do NaCl/NaHCO3 stay extracellular or go into cell when you add them in solution intravenously?
Stay extracellular
Does K stay extracellular or go into cell when you add it in solution intravenously?
goes into cell