Potassium Flashcards
Potassium Balance
Plasma concentration: 3.5-5 mEq/L
Abundant in ________
ICF
Factors affecting K+ regulation
Aldosterone
Sympathetic stimulation (eg, ____________)
_________ - an increase in cellular uptake of
K after a meal
epinephrine
Insulin
Transcompartmental exchange of H+ and K+
In metabolic acidosis, the body tries to balance the increased acidity by exchanging H+ for K+ in cells. As H+ move into cells to reduce acidity, K+ move out of cells into the bloodstream, leading to _________
hyperkalemia
Trans-compartmental exchange
When Acidic ECF (metabolic acidosis)
H+ IN
K+ OUT
When Basic ECF
(Metabolic alkalosis)
K+ is IN
H+ is OUT
Trans-compartmental exchange
When there is an increase in K+ in ECF→ __________
metabolic acidosis
When there is a decrease in K+ in ECF→ ___________
metabolic alkalosis
Distribution of body fluid
The extracellular space includes
the vascular compartment and
the interstitial spaces.
2/3(66%) is the ___________
1/3(33%) is the ECF
80% interstitial fluid
20% blood
ICF
Extracellular & Intracellular Fluid Composition
ECF Ca2+. Na+, Cl-, HCO3
What ion is in the Intracellular fluid?
K+ (potassium)
think of parents being inside a house
Chloride–Bicarbonate Exchange
Normally, Cl− is absorbed along with Na+ throughout the tubules. In situations of vomiting, the kidneys substitute HCO3− for the Cl− anion, thereby increasing its absorption of HCO3 -
_________ - increase in pH induced by excess
HCO3− reabsorption due to a decrease in Cl− levels
Hypochloremic alkalosis
_______________ - decrease in pH by decreased HCO3−reabsorption due to an increase in Cl− levels
Hyperchloremic acidosis
If we lose HCO3- by diarrhea our body compensates by adjusting other ions (_______)
Chloride (Cl-)
Anion Gap = [Na+- (Cl- + HCO3-)]
Anion gap is caused by negative charges on proteins and organic acids (e.g.lactate, keto acids)
Anion gap=The difference between the ________ concentration of the major measured cation (Na+) and the sum of the measured anions (Cl− and HCO3−)
Why?
The concentration of ___________anions (phosphates, sulfates, organic acids, and proteins)
plasma
unmeasured
Anion gap for what?
Easy to measure these ____________ (Na+, Cl-, HCO3- ) and their central role in maintaining acid-base balance
- Readily measured with _____
- Reflect key components of ECF
→ Useful for Diagnosing ____________ Disorders
electrolytes
low cost
acid-base disorders
Normal Anion Gap (Hyperchloremia)
Increased Anion Gap (Normochloremia)
Basement membrane is negatively charged.
Cationic ions can get through the membrane
Anionic ions cannot get through the membrane
Acidic drug secretion via transporters in PCT instead of glomerular filtration?
OAT transporters
