Body Fluids Flashcards
What percentage of the body weight is comprised of water in lean men?
70%
What percentage of the body weight is comprised of water in the average adult male?
60%
What percentage of the body weight is comprised of water in obese women?
50%
How much water is inside the human body, approximately?
40L
Under normal conditions the intake and output of water should be balanced at around …
2.5 L/day
Of the water outputs what is the primary site of regulation?
kidneys
The 40 L of fluid within the body are compartmentalized into four main body fluid compartments, what are they?
- Intracellular Space
- Interstitial Space
- Plasma
- Transcellular Spaces
Where is the fluid within the cells of the body?
Intracellular Space
What is the boundary of the Intracellular Space?
Plasma Membrane
Where is the fluid that bathes the cells of the body?
Interstitial Space
What is the boundary of the Interstitial Space?
It is the compartment between everything else, so it doesn’t really have a defined boundary.
What is the fluid within the blood vessels?
Plasma
What is the boundary of the Plasma?
Endothelial Cells
What is the space called that holds the fluid within the specialized fluid spaces of the body, such as the CSF, pleural, synovial, and peritoneal fluids?
Transcellular Spaces
What is the boundary of the Transcellular Spaces?
Epithelial Cells
What substances can pass through endothelial cell clefts?
Water, glucose, oxygen, WBCs, Sodium
What substances cannot pass through endothelial cell clefts?
RBCs & Large MW proteins
What substances can pass through the plasma membrane with intact channels/carriers?
Water, glucose, oxygen, sodium
What substances cannot pass through the plasma membrane with intact channels/carriers?
RBCs, Large MW proteins, WBCs
The ability of a solute to pass through a barrier is numerically described by a …
reflection coefficient
Which Body Fluid Compartment is the most restrictive?
Transcellular Spaces (epithelial cells)
Which Body Fluid Compartment is the least restrictive ?
Plasma (endothelial cells)
The plasma and interstitial fluid compartments are very similar in composition to one another in regards to …
low MW solutes
What is the main difference between the plasma and interstitial fluid compartments in regards to permeability?
The plasma compartment typically retains large MW proteins that don’t escape into the interstitial fluid under normal conditions.
What is the primary mechanism of transport for the solutes within the body fluids?
Diffusion
Water itself can also move across the body fluid compartments via a process known as …
bulk flow
The large-scale movement of water and dissolved solutes based on pressure gradients.
Bulk Flow
The lymph body fluid compartment is considered a subset of what fluid type?
ECF
Based on the number of molecules per volume of fluid
Molarity
Based on the number of particles after dissociation per volume of fluid
Osmolarity
Based on the amount of charged solute per volume of fluid.
Equivalency
The Intracellular fluid has a greater concentration of what substances?
Potassium, Proteins & Phosphates
The Extracellular Fluid (interstitial & plasma) has a greater concentration of what substances?
Sodium, Calcium, Chloride, & Bicarbonate
Which of the extracellular components has a higher osmolarity?
Plasma, because of the large MW proteins stuck inside
The body fluid compartments must have the same concentration of cations and anions.
Electroneutrality
The negatively charge proteins that are stuck in the plasma, such as albumin, attract small cations into the plasma and repel small anions towards the interstitial space. This redistribution of cations and anions between the compartments is referred to as …
Gibbs-Donnan Effect
Solute that dissolves in water but may or may not be able to penetrate the plasma membrane freely
Osmotic solute
Solute dissolves in water, but are unable to penetrate the plasma membrane
Tonic solutes
What is the volume of Intracellular Fluid?
25 L
What is the osmolality of Intracellular Fluid?
290 mOsm
What is the volume of Interstitial Fluid?
11 L
What is the osmolality of Interstitial Fluid?
290 mOsm
What is the volume of Plasma?
3 L
What is the osmolality of Plasma?
300 mOsm
What is the volume of the Extracellular Fluid?
14 L
Isotope of water, equilibrates in the TBW
Titrated Water
Large MW carbohydrate, equilibrates in the ECF
Inulin
Binds to albumin, equilibrates in the plasma
Evan’s Blue Dye (EBD)
Inulin is unable to penetrate the …
plasma membrane
What is the dye dilution principle equation?
volume (mL) = Amount (mg) / Final Concentration (mg/mL)
