Physiology Flashcards
what is the largest source of fluid entering the body
the intake of water-containing foods and beverages
a smaller contribution to the source of fluid entering the body is metabolism - explain
dehydration reactions, ETC
Water is lost how?
exhalation, skin, perspiration, urinary loss, fecal loss
a normal healthy individual’s body fluid balance is primarily achieved by
urine production
how do the lungs help control body fluid volume and body fluid composition
bring in oxygen and eliminate CO2
how does the GI tract help control body fluid volume and body fluid composition
brings in nutrients like water, sugar, protein, fats, and salts
how does the heart/circulation help control body fluid volume and body fluid composition
propels the blood around the body as a means of exchanging wastes and nutrients with the cells of the body
how do the kidneys help control body fluid volume and body fluid composition
eliminate various wastes and control the amount of water and salts
what is the actual fluid that surrounds each cell is not the blood itself but
interstitial fluid
the interstitial fluid is inside or outside the blood vessels
outside
what does interstitial fluid primarily contain
sodium chloride
“Average male” is what
70kg or 154 pounds
approximately what % of body weight is comprised of water in adults
50-70%
what is the 60-40-20 rule for the average male
60% total body weight is water
40% total body weight is intracellular
20% total body weight is extracellular
most of the tissues in the body contain approximately what percentage of water content by weight
70-80%
what percentage of water content are the skeletal bones
22%
what percentage of water content is adipose tissue
10%
under normal conditions, the intake and output should be balanced around
2.5 liters a day
of the outputs, what is the primary site of regulation
the kidneys (urine is about 1500mL a day)
large volume of urine = what concentration
low concentration (clear)
small volume of urine = what concentration
high concentration (dark)
what is the intracellular space
the fluid within the cells of the body
what is the boundary for intracellular space
plasma membrane
what is the interstitial space
the fluid that bathes the cells of the body (part of the extraceullar)
what is the boundary for interstitial space
utilizes all the other boundaries (sandwiched in-between)
what is the plasma
the fluid within the blood vessels
what is the boundary for the plasma
endothelial cells
what its the transcellular spaces
the fluid within specialized fluid spaces of the body, such as the CSF, pleural, synovial, and peritoneal fluids
this is VERY retractable, tightly controlled
what is the boundary for the transcellular spaces
epithelial cells
why can we see similarities with the plasma and interstitial fluid
the endothelial clefts have low restrictiveness
can RBCs pass through the endothelial cell clefts? will the plasma membrane have intact channels/carriers?
No, No
can large MW proteins pass through the endothelial cell clefts? will the plasma membrane have intact channels/carriers?
No, No
can water pass through the endothelial cell clefts? will the plasma membrane have intact channels/carriers?
Yes, Yes
can glucose pass through the endothelial cell clefts? will the plasma membrane have intact channels/carriers?
Yes, Yes
can oxygen pass through the endothelial cell clefts? will the plasma membrane have intact channels/carriers?
Yes, Yes
can WBCs pass through the endothelial cell clefts? will the plasma membrane have intact channels/carriers?
Yes, No
can Sodium pass through the endothelial cell clefts? will the plasma membrane have intact channels/carriers?
Yes, Yes
Explain how WBCs passing through endothelial cell clefts can be both a yes or no
WBCs shouldn’t be leaving under normal healthy conditions but they are capable
ex: infection
what is a 0 for the reflection coefficient
barrier is freely permeable to the solute
what is a 1 for the reflection coefficient
barrier is impermeable to solute
the makeup of transcellular spaces can vary greatly depending on
the specific needs of the compartment
what is the primary mechanism of transport for the solutes within the body fluids
diffusion
oxygen and nutrients diffuse from an area of what concentration to where
high concentration within the blood stream to an area of low concentration in the interstitial space
oxygen and nutrients can traverse the plasma membrane and enter the cells of the body- yes or no?
yes
CO2 and other waste products move in concentrations from
low to high, passing from the cells to the intermediate zone of the interstitial fluid and then the bloodstream
How long does it take glucose to diffuse 1 cm?
13.9 hours
diffusion is a SLOW process
what is bulk flow
large scale movements of water and dissolved solutes based on pressure gradients
as the heart pumps, fluid is pushed between the openings of endothelial cells and into the interstitial fluid
what happens to the fluid?
most gets returned back into the blood stream
what doesn’t get reabsorbed is moved into the lymphatic system where it is cleaned and returned to the bloodstream
the lymph body fluid compartment is considered a subset of
the extracellular fluid
what is total body water (TBW)
all water within the body
what is intracellular fluid (ICF)
fluid contained within the boundary of the plasma membranes
what is extracellular fluid (ECF)
all fluids in the body outside of the plasma membrane boundaries
where is interstitial fluid located
between the body fluid compartments
where is plasma
within the boundary of endothelial cells in lymphatic vessels
where is transcellular fluid
within the epithelial cell boundaries
the volume of a body fluid compartment can changed based on
solute levels
water moves via osmosis from an area of what to what concentration
low solute to high solute
Osmolarity can change with
temperature since water volume changes with temperature
Osmolality does or does not change with temperature
does not
molarity of the solution is based on
the number of molecules per volume of fluid
osmolarity is based on the
number of particles after dissociation per volume of fluid
the equivalency of the solution is based on
the amount of charged solute per volume of fluid
intracellular osmolarity =
extracellular osmolarity
these always match, are balanced
what do you take into account when thinking of osmolarity
does it dissociate when placed in this aqueous environment
regarding osmosis, if a solute is unable to create a balance, the water (solvent) will move
via osmosis towards the area of high concentration
what are the extracellular fluids
Sodium, Calcium, Chloride, Bicarbonate
what are the intracellular fluids
Potassium, Proteins, Phosphates
what maintains the high concentration of sodium ions outside the cells and high concentration of potassium ions inside of the cells
Na+/K+ pump
Would interstitial fluid or plasma have higher osmolarity?
Plasma
it has the large MW proteins aka a higher concentration so, higher osmolarity
increased osmolarity = what regarding concentration
increase
for every existing cation, there is a
corresponding anion
in a hypertonic solution, the osmolarity of the solution is
greater than the fluid inside the cell
explain electroneutrality
the body fluid compartments must have the same concentration of cations and anions, the body fluid compartments are electroneutral!!!
why is the plasma solute concentration higher than that of the interstitial space
because of the Gibbs Donnan effect
the negatively charged proteins in the plasma attract sodium ions
osmotic solute
dissolves in water
Tonic solute
does not penetrate plasma membrane
non-tonic solute
penetrates plasma membrane
in a hypotonic solution, the osmolarity of the solution is
lower than the inside of the cell
isotonic solutions
there is still movement of water into and out of the cell but there is no NET influx of water
non-osmotic solute
does not dissolve in water
describe what would happen in a hypotonic solution
water would enter the cell by osmosis and the cell would swell and potentially burst
what would happen in a hypertonic solution
Water would travel towards the high concentration of non-penetrating solutes outside the cell, leading to shrinkage of the cell
an osmotic solute does dissolve in water, but
may or may not be able to penetrate the plasma membrane freely
tonic solutes dissolve in water, but
are unable to penetrate the plasma membrane
example of tonic solute
Na+
example of non-tonic solute
Ethanol
will glucose dissociate when placed in a solution
no, so less osmotic force will be exerted
Regarding the dilution principle, what is the volume of the intracellular fluid
25 L
Regarding the dilution principle, what is the volume of the interstitial fluid
11 L
Regarding the dilution principle, what is the volume of the plasma
3 L
Regarding the dilution principle, what is the extracellular fluid
interstitial fluid and plasma
what is the dilution method used to estimate
body fluid compartment volumes based on the characteristic of the barriers
regarding the dilution method, all samples will be
placed into and taken out of the plasma fluid compartment
formula for the dilution method
Volume = amount (mg) / final concentration (mg/mL)
trilated water
can easily pass through the endothelial cell clefts and plasma membrane to enter all of the body fluid compartments
inulin is a
large MW carbohydrate that can pass through the endothelial cell clefts, but is unable to penetrate the plasma membrane
Evan’s blue dye binds to
albumin (protein), and thus does not pass through the endothelial cell layer or the plasma membrane
what would be the expected volume of fluid that tritiated water would equilibrate in
40 L
what would be the expected volume of fluid that inulin would equilibrate in the ECF
14 L
what would be the expected volume of fluid that EBD would equilibrate in
3 L
what do volume-osmolarity diagrams depict
changes in volume on the x-axis
changes in osmolarity on the y-axis
