The flashcards below were created by user
ijesc
on FreezingBlue Flashcards.
-
what % of mass in male is water
60%
-
what % of mass in females is water
50%
-
what % of mass in infants and children is water
75%
-
vol of water healthy young male
42L
-
intracellular fluid in male
-
extracellular fluid in male
-
plasma is part of _____ fluid
extracellular
-
-
hormones and nerves play a part in
control of volume and osmolality
-
control of volume and osmolality is influenced by
hormones and nerves
-
how many types of subjects and what are they
- 5
- control
- water
- saline
- urea
- water+ADH
-
what did the control subject consume?
consumed no fluid during the class
-
what did the water subject consume?
drank 20mL of water/kg
-
what did the saline subject consume?
drank 7mL of 0.9% NaCl solution/kg
-
what did the urea subject consume?
drank 20mL of 1.8% urea solution/kg
-
what did the the water + ADH subject consume
drank 20mL of water/kg followed immediately by a dose of lysine vasopressin (ADH) by nasal instillation
-
what was the subject procedure
- empty bladder
- weighed
- consumed test solution over 15-20min period
- urine was collected every 30mins
-
urine vol was measured in
mL
-
osmolality was determined by
freezing point depression
-
osmolality results were expressed in
mosm/kg H2O
-
In class, asked to plot ___ & ___ as a function of ______
- urine (mL/30min)
- osmolality (mosm/kg)
- time
-
how long did the test run for
150mins total
-
how to calculate for osmolar excretion per 30mins?
urine flow * osmolality
-
what is the osmolality of 0.9% saline solution
300mosm/kg
-
what is the osmolality of 1.8% urea solution
300mosm/kg
-
is 0.9% saline isotonic and why
yes. not net mvt of water
-
is 1.8% urea isotonic and why
no, it is hypotonic. urea moves down conc grad and brings urea and water into cell, causing it to swell
-
if a cell is in a hypotonic solution, the cell will
swell
-
if a cell is in a hypertonic solution, the cell will
shrink
-
is 0.9% saline iosmotic
yes
-
what is iosmotic
having the same pressure
-
does 0.9% saline go into ICF?
no
-
why were subjects who drank 0.9% saline only given 7mL/kg instead of 20mL/kg?
gives same ECF expansion as saline only goes into ECF
-
what is effect of drinking 20ml/kg of water on urine flow rate and osmolality
- diuresis
- dramati incr in flow rate
- decr in osmolality
-
which solution produced similar urine flow rate to that of the water load and what was different
- 1.8% urea
- water has lower osmolality; urea has higher osmolality
- urea needs to be excreted in urine=active osmolality increasehehe
-
why urea has greater flow rate than saline
- urea is hypotonic = reduces ADH = not reabs from cd in kidneys
- saline = isotonic = water doesnt enter cell = osmoreceptors not active
-
did urea or saline have greater flow rate?
urea
-
which soln had greatest osmolar excretion + why?
- urea
- active urea excretion
-
was diuresis due to vol expansion or dilution of osmolality or both? why?
- both.
- mainly water caused osmolality dilution
- smaller effect detected by osmoreceptors
-
which osmoreceptors detect change and where are they located
- supraoptic nucleus
- paraventricular nucleus
- in hypothalamus
-
if osmoreceptor swells, effect is?
ADH prodn switched off
-
what is effect of ADH
stops diuresis
-
mechanism via water loading that causes diuresis are:
- 1 stim of osmoreceptors = ADH inhibition
- 2 incr in ECF vol = incr urine produced
-
If water transfused into plasma, where does it go?
-
If normal saline transfused into plasma, where does it go?
all in ECF
-
If urea transfused into plasma, where does it go?
ECF and ICF
-
If 5.5% mannitol transfused into plasma, where does it go?
- mostly ECF
- some may go into ICF
-
If plasma transfused into plasma, where does it go?
stays in vascular compartment
-
If 10% albumin and 0.9%saline transfused into plasma, where does it go?
- vascular compartment
- may have slow turnover to ECF
-
If blood transfused into plasma, where does it go?
vascular compartment
-
If 5.4% glucose transfused into plasma, where does it go?
- initially into ECF
- insulin required to enter ICF
-
how to calculate osmolality
osmolality of plasma * old vol/new vol
-
calculating osmolality with changes in salt conc
[(orig vol*orig osmolality)+(new vol added*osmolality in it)]/total vol
|
|