Body Fluids & Electrolyte Balance (Final) Flashcards
What are the 3 body fluid compartments?
1) intracellular fluid compartment
2) extracellular
3) transcellular
What makes up the extracellular fluid compartment?
Test q
Interstitial fluid and blood plasma
Note: constituents may be considerably different from plasma or interstitial fluid (Ex: ependymal cells are in ventricles, astrocytes are in BBB)
What 4 fluids are in the transcellular fluid compartment?
1) synovial fluid
2) peritoneal fluid
3) pericardial fluid
4) CSF
Why do women and men have different water composition?
Because of body fat, so men have more fat and water than women in the body
Intracellular fluid makes up ____ of body weight. The constituents may very and concentrations are very similar cell to cell within that tissue
40%
Extracellular body fluid takes up 20% of body weight. What percent of extracellular fluid is interstitial and what is plasma?
75% is interstitial fluid, 25% is plasma
Note: capillary pores help with interstitial exchange
**Plasma and interstitial fluid essentially have the same composition other than plasma proteins
Most body fluid volume is what fluid?
Test q
Intracellular fluid
The blood has what fluid?
Both extracellular and intracellular fluid
What fluid is found in RBCs?
Intracellular fluid
Blood volume is about 7% of body weight in any adult. What is the ratio of plasma to blood?
60% is plasma and 40% is RBCs
What is the first symptom when you have a decrease in RBCs?
Fatigue/tiredness
What is hematocrit?
Test q
Fraction of blood that is RBCs
(For men it’s 40%, women it’s 36%)
What is anemia? What are the causes?
Low RBC count
-pathologies
-chemotherapy
-hemorrhage (leakage of blood)
What is polycythemia? What are the causes?
More RBCs than the normal amount
-caused by severe COPD (lack of oxygen so the body will make more RBCs to compensate)
-also caused by living at high altitudes (will need more oxygen to survive)
What cations are found in extracellular fluid?
Test q
Mostly just sodium
What anions are found in extracellular fluid?
Test q
Cl- and bicarbonate
What cations are the major players of APs?
Sodium and potassium
What cations are the in the intracellular fluid?
Mostly potassium
What sets up the concentration gradient between extracellular and intracellular fluid compartments?
Sodium potassium pump
3 Na out for every 2 K in
What 2 molecules can only travel with sodium between compartments?
Glucose and AAs
What is the transport maximum for reabsorption of glucose?
Hint- it’s a number
Test q
100 mg/dL is the max you can reabsorb glucose and if there’s anymore then you gotta pee it out (more = diabetic)
Should the total intake and output of water be the same?
Yes!!!!
What output numbers will change if the environment is hot?
Insensible skin and lungs, and sweat will increase
T/F insensible loss will be essentially the same in a controlled environment
True
Metabolism of water is synthesized by the metabolism of….
CHO
Insensible water loss is by….
Evaporation (not conscious of the loss)
T/F: fluid and electrolyte balances are necessary in the long term to maintain life
True
Fluid loss = ?
Fluid intake
Electrolyte loss =
Electrolyte intake
Fluid intake is regulated by what?
Thirst mechanism and drinking habits
Electrolyte intake is governed by?
Dietary habits
Fluid output is regulated mainly by?
Kidneys
Electrolyte output is regulated mainly by?
Kidneys
The distribution of body fluid across cell membranes is determined by?
osmotic fluid (mainly electrolytes/small solutes)
The distribution of body fluid across capillaries (plasma and interstitial space) is determined by?
hydrostatic and colloid osmotic forces across capillary membrane
Water moves rapidly across cell membranes bc of ___________, therefore the osmolarities of intracellular and extracellular fluids remain almost exactly equal to each other except for a few minutes after a change in one of the compartments
aquaporins
Cell membranes are almost completely impermeable to many solutes, therefore, the number of osmoles in the extracellular or intracellular fluid generally remains constant unless solutes are added to or lost from the extracellular compartment bc of
transporters/pumps
What are osmoles?
measure of osmotic pressure
The mass of one mole of a substance is equal to the atomic or molecule mass of the substance expressed in grams. This value is called the….
gram molecular mass
A mole is the weight in grams of substance equal to its….
gram atomic or molecular weight
The total number of solute particles in the solution is the….
osmoles per liter solvent
1 osmole = 1 mole of….
solute particles
1 mole of glucose = ___ osmole = 180 grams of glucose
1
1 mole of NaCl = ____ osmoles = 58.5 grams
2
** 2 osmoles bc NaCl dissolves into 2 particles
milimoles are also known as…
test q
milliosmoles or mOsm (milligrams of solute)
What is osmolality?
osmoles per Kg water (osmolarity per L of water for clinical values)
The key to tonicity is knowing the relative concentration of _____________________ in the cell and in the solution
non-penetrating solutes
There are 3 roles to predict tonicity. What are they?
test q
1) If the cell has a higher conc. of nonpenetrating solutes than the solution, there will be net movement of water into the cell. The cell swells/lyses, and the solution is hypotonic
2) If the cell has a lower conc. of nonpenetrating solutes than the solution, there will be net movement of water out of thr cell. The cell shrinks/shrivels/crenation and the solution is hypertonic
3) If the conc. of nonpenetrating solutes are the same in the cell and the solution, there will be no met movement of water at equilibrium. The solution is isotonic to the cell
What happens to fluid if you add isotonic NaCl?
there will be an increase in the extracellular fluid volume
What happens to fluid if you add hypertonic NaCl?
test q
-extracellular osmotic pressure increases
-water leaves cell and goes out into the extracellular space
-there will be a rise in osmolarity in both intracellular and extracellular fluid bc the conc. goes up
What happens if you add hypotonic NaCl?
-the extracellular osmotic pressure decreases
-water will move into the cell from the extracellular space to equalize the osmolarity
What does isotonic mean?
test q
the cell has same osmolarity as body fluids
What does hyperosmotic mean?
test q
higher osmolarity than body fluids
What does hypoosmotic mean?
test q
lower osmolarity than body fluids
When glucose reaches cells it will be converted into….
hexose monophosphate
Why is there phosphocreatine in intracellular fluid but not in plasma or interstitial?
its a high energy phosphate, so it is in the intracellular fluid as storage for energy to be used eventually