Salt and Water-Fluid Homeostasis at the Cellular and System Level Flashcards
there are many places in the animal body that contains a selectively permeable membrane for water. If water moves from side A to side B, which side has the lowest osmotic pressure?
side A
which body compartment contains the highest proportion of total body water?
intracellular fluid
What are the percentages of body weight that is contained within each fluid compartment?
Intracellular fluid = 40%
Interstitial fluid = 15%
Intravascular fluid = 5%
edema is an abnormal increase in the volume of which type of fluid?
interstitial fluid
what electrolytes are in which body fluid compartment?
sodium: intravascular fluid
potassium: intracellular fluid
the desert-dwelling kangaroo rat can derive up to 100% of its water needs from metabolic water. What is metabolic water?
water obtained from the krebs cycle and electron transfer chain
What happens once a dairy cow begins lactation
increased water loss as a result of milk production and increased fecal output
A feline patient presents to the emergency room in Tucson after having been stuck outside for a whole day. The cat is now dehydrated. From which body compartment is water lost in the early stages of dehydration?
extracellular fluid
Coming back to the dehydrated feline patient. What would you expect to see on blood tests for this cat?
electrolyte levels should be normal is the kidneys are working
Due to it being the most common extracellular ion, which would be the most important electrolyte to supplement in your fluid replacement plan for this cat?
sodium
If you were to provide this cat with intravenous fluids, which type of fluid would be most likley to cause the cat’s red blood cells to fill with water and burst?
hypotonic saline
body fluid takes up more volumes than body water because
it has solutes in it
what body compartment contains a higher percentage of total body water
intracellular
what molecule would exert greater osmotic pressure when in water, glucose or NaCl?
NaCl
what odes isotonic mean in relation to red blood cells?
fluid has the same osmotic pressure as the RBC
if the RBC was placed in hypertonic solution, which way would water want to go?
water would move from the RBC to the extracellular fluid
if the RBC was placed in a hypotonic solution, which way would water move?
water would move from the extracellular fluid into the RBC
when an animal is mildly dehydrated, the electrolyte levels will typically be
normal because electrolytes are excreted through the kidneys in proportion to water loss in an attempt to keep things in balance
in early dehydration, where is fluid lost from?
extracellular fluid
If a 11lb (5 kg) cat is 10% dehydrated, about how much fluid needs to be replaced?
0.5 L
A racing horse weighs 500 kg. During a race, horses lose fluid through sweating and other insensible losses. After the race, you are asked to replace fluid losses. Therefore, you must calculate the estimated body fluid compartment volumes. The horse is estimated to have a total body water percent of 60%. Calculate what the volume of these body fluid compartments would be: ICF, ECF, ISF, and P (plasma).
ICF: 200L, ECF: 100L, ISF: 75L, P: 25L
If a 500 kg horse was 5% dehydrates, how much fluid would roughly have to be replaced if you were to rehydrate the horse?
25L
Imagine you are treating an 18-week old puppy with parvovirus. Parvovirus is a viral infection that attacks white blood cells and gastrointestinal cells to cause severe vomiting and diarrhea, particularly in puppies. The puppy has severely decreased skin turgor (a skin tent), has low blood pressure and his eyes are sunken. You suspect he is severely dehydrated (10% dehydrated). The best way to rehydrate a severely dehydrated animal is to give fluids directly into the bloodstream (intravenously). Intravenous fluids come in several different formulations. Most of them have saline in them (NaCl) and are isotonic. They can also be hypertonic or hypotonic. Which type of fluid would be the best choice to ensure that the puppy’s RBCs do not swell up or shrink when the fluid is given IV?
Isotonic
Some fluids that can be used IV contain NaCl and some also contain glucose. When added to a fluid, which molecule would most increase the osmotic pressure of that fluid?
NaCl
