LEC4 - POTASSIUM AND CHLORIDE Flashcards
is the major intracellular cation in the body
Potassium (K+)
the concentration of potassium inside is how many times greater than the outside
20 times greater
In laboratory, Only how many percent of the body’s total K+ circulates in the plasma?
2% - only two percent is detected in serum
potassium’s regulation includes
o Neuromuscular excitability
o Contraction of the heart
o Intracellular fluid volume
o Hydrogen ion concentration
about how many mmol/ L are found in ECF
3-5 mmoll/L
how can potassium helps in intracellular fluid volume
Correct water distribution inside the cell to prevent bursting or shrinking
a stable electrical charge across a neuron’s membrane when it is not actively sending signal
resting membrane potential - RMP
relationship of the values of potassium, RMP, and action
inversely
if someone is moving, what is happening to the potassium values
increased
if someone is moving, what is happening to the RMP values
decrease
an increased in heartbeat will affect the potassium values and the RMP, in what way it can influence the values of potassium and RMP
increase potassium and decrease RMP
the elevated potassium, and an increase in heart beat will affect the heart in what way
it can cause sudden stoppage of heart or heart attack
this ion is the one responsible in the pH of blood
hydrogen ion
once the potassium goes out of the cell, the NA and hydrogen ions will replace the lost potassium.
correct?
correct
an increase of hydrogen ion will cause
metabolic acidosis
a decrease of hydrogen ion will cause
alkalosis
if there’s metabolic acidosis, the hydrogen ions in the blood is elevated. To lessen or correct it, what will be the role of potassium?
potassium will go out of the cell so the hydrogen ions can go inside the cell and lower the values of hydrogen ions in the blood that causes acidosis.
if there’s metabolic alkalosis, the hydrogen ions in the blood is decreased. To elevate or correct it, what will be the role of potassium?
potassium must go inside the cell so the hydrogen ions can go outside and go to the bloodstream and elevate the number of hydrogen ions.
Na+-K+ ATPase pump mechanism
active transport
2 REGULATION OF POTASSIUM
the use of Na+-K+ ATPase pump and the
Diffusion of potassium out of the cell into the ECF and plasma
when do potassium uses passive diffusion instead of active transport?
when there’s a decrease in pump activity such as
o Depletion of metabolic substrate > e.g.glucose for ATP production
o Competition for ATP between the pump and other energy-consuming activities
o Slowing of cellular metabolism
Three factors that influence the distribution of K+ between cells
and ECF are as follows:
(1) K+ loss frequently occurs whenever the Na+, K+ ATPase pump is inhibited
(2) insulin
(3) catecholamines
(1) K+ loss frequently occurs whenever the Na+, K+ ATPase pump is inhibited by conditions such as __, __, and ___
hypoxia, hypomagnesemia, or digoxin overdose
(2) insulin promotes acute ____ by increasing Na+, K+-ATPase activity;
entry of K+ into skeletal muscle
and liver
insulin promotes the entry of potassium into the cell thus will result in what condition
hypokalemia
a catecholamines that is a B stimulator that promotes cellular entry of K
epinephrine
a catecholamines that is a B blocker that impairs cellular entry of K
propanolol
OTHER FACTORS that might affect distrbution of potassium aside from inhibited atpase pump, insulin, and cathecolamines
exercise
hyperosmolality
cellular breakdown
exercise can cause false __ in potassium, please explain why as well
false elevations as the K is released from muscle cells during exercise
increase plasma K+ by ___mmol/L with
mild to moderate exercise
0.3 to 1.2
increase plasma K+ by ___mmol/L with
exhaustive exercise
2-3 mmol/L
can elevations due to exercise be reversed?
These changes are usually reversed after several minutes of rest
causes water to diffuse from the cells,
carrying K+ with the water, which leads to gradual
depletion of K+ if kidney function is normal
Hyperosmolality
conditions we can observe elevation of potassium that results from cellular breakdown are
are severe trauma, tumor lysis syndrome, and massive blood transfusions.