Fluid and Electrolyte Balance Flashcards
Know the kidneys maintain the body’s fluid and electrolyte balance.
kidney compensation, secretion of H+
Be able to define oncotic (osmotic) pressure and hydrostatic pressure.
Oncotic pressure: form of osmotic pressure exerted by proteins in blood plasma that will pull water into blood
Hydrostatic pressure: drive fluid transport between capillaries, tissues, and blood, original source is hb and elastic recoil of aorta
How do we regulate the amount of water and solutes lost (remember those 3 hormones that are regulating renal Na+and Cl- ) (ADH, Aldosterone, ANP)
ADH: promotes insertion of aquaporin-2 into principal cells of collecting duct
Aldosterone: promotes urinary Na+ and Cl- reabsorption
ANP: promotes excretion of Na+ and Cl- followed by H2O
What are the main functions of electrolytes?
retain water, bring water in and out of cells, help maintain pH, carry electrical current, cofactor w/ enzymes, control osmosis of H2O
List the main electrolytes (sodium, potassium, chloride, calcium, magnesium, and bicarbonate)
sodium, potassium, chloride, calcium, magnesium, bicarbonate
What is the major homeostatic challenge in acid-base balance?
keeping H+ concentration (pH) of body fluids at appropriate levels
Be able to describe the protein and carbonic acid-bicarbonate buffer systems.
Protein: most abundant in ICF, free carboxyl group acts as acid by releasing H+, free amino group acts as base to combine H+
H2CO3: CO2 + H2O -> H2CO3 -> HCO3- + H+, significant in ICF and ECF, HCO3 acting as weak base, H2CO3 weak acid
How does respiration of CO2 affect the pH of body fluids?
increase in CO2 decrease in pH in body fluid
Define acidosis and alkalosis
Acidosis: low pH, too much H+
Alkalosis: high pH, too little H+
How does the respiratory system regulate pH?
through O2 and CO2 exchange, CO2 and H+ are why we breathe, we have chemoreceptors that regulate pH, respiratory compensation
Why does respiratory acidosis occur and why does respiratory alkalosis occur?
Acidosis: increase in carbonic acid
Alkalosis: decrease in carbonic acid
results from changes in pCO2 in systemic arterial blood
How does the renal system regulate acid base balance?
secretion of H+ and HCO3-
Why does metabolic acidosis occur and why does metabolic alkalosis occur?
Acidosis: decrease bicarbonate or increase in H+
Alkalosis: increase in bicarbonate, decrease in H+
