Week 11: fluid acid base balance pt 2 Flashcards
When our Na concentrations are getting a bit low, its possible for what?
our kidneys to make urine that is almost Na free
- that is how effective the Aldosterone carrier (Na ion exchanger or Na K exchanger) is.
Usually, we’re gonna adjust our body content of Na by adjusting what?
how much Na is in urine
Where do we lose Na in?
Saliva, gastric secretions, pancreatic secretions, and intestinal secretions
Your digestive tract and salivary glands produce how much digestive fluids?
8 liters of digestive fluids a day
what is the total body pool of Na?
somewhere between 2800-3000 m Eq of Na ( numbers are not important, we’re working our way up to
those 8 liters of digestive juices alone are gonna have you lose?
1200-1400 mEQ
- you’re losing almost half of your sodium a day just in digestive secretion, not counting urine or sweat
we have to be really good at retaining Na and causing ingestion of Na to maintain?
what our body pool is supposed to be
situations that cause my Na levels to go up will also cause what to go up?
my chloride levels to go up
what is the reason?
sodium and chloride hang out together (opposites attract) and so if i have more Na, im going to tend to hold on to more chloride
the total body pool of K is?
4000 mEQ (not important, just for comparison)
the normal range of the plasma Na concentration is?
between 136-146 mEQ
normal K concentration in the blood is?
4-5 mEQ
why is there such a big difference?
the K is inside the cells and the Na is outside the cells
because or normal plasma K levels are so low, what happens?
you can lose a third to a half of your total body K pool before you get low K (goes into the blood and into the urine)
we’re able to maintain our?
normal K levels
how can you lose that much K?
if most of K is inside your cells, to lose K you have to :
- literally lose the whole cell where the cell has to die and rupture and then the K will go into the extracellular fluid.
-
things that are gonna cause a lot of cell death can cause you to?
lose a lot of K (hypokalemia)
what are the causes?
where you have lots of cells die in a short time
- burns
- crash injuries
- starvation
- vomiting
Vomiting: how you secrete HCI acid?
hydrogen ion gets pumped into the lumen of the stomach in exchange for K ion. so gastric juice has a pretty good concentration on K and vomiting a lot (numbers of times not vol) you lose K in the juice and the acid can start damaging cells on the way out.
what is HYPOnatremia?
electrolyte imbalance where a plasma Na concentration BELOW 136mEq/L
what does HYPOnatremia look like?
hypervalemia
usually, we get HYPOnatremic because?
of excess water retention or water ingestion
Aside from those causes, what else are causes?
- overuse of Na wasting diuretics (where we put the Na in the filtrate to trap water. this is where the H20 is gonna go just like the kidneys)
- also large lose of Na like profuse sweating
- adrenal insufficiency (not being able to make enough aldosterone so you won’t be able to absorb the amount of Na i need to reabsorb)
- kidney failure (bc you’re not reabsorbing Na)
- liver failure (bc the fluid thats supposed to be in the blood is elsewhere)
all of this is a problem bc it messes with your?
action potentials