Question | Answer |
Define an ion. | A charged particle. |
Define an acid. | Liberates hydrogen ions in solution. |
Define a base/alkali. | Accepts hydrogen ions in solution. |
Normal blood values of pH. Arterial Blood. | 7.35 - 7.45 |
Normal blood values of pH. Venous blood and interstitial fluid. | ~7.35 |
Normal blood values of ph. ICF | ~6 - 7.35 |
Homeostasis of hydrogen. | Proteins are sensitive to pH.
Diets high in protein tend to acidify blood. |
What are the 3 mechanisms to regulate pH? | Buffer system. Exhalation of CO2 (respiratory system). Kidney excretion of hydrogen (urinary system). |
Describe the buffer system. | Prevent rapid/drastic changes to pH (shock absorber) |
Name the 3 buffer systems. | Protein. Carbonic acid - bicarbonate. Phosphate |
Describe the protein buffer system. | Abundant in intracellular fluids and in plasma. Amino acids contains at least one carboxyl group and one amino group (acts like a acid and a base). Hemoglobin acts as a buffer in blood by picking up CO2 and hydrogen. |
Describe the carbonic acid-bicarbonate buffer system. | Acts as extracellular and intracellular system. At pH of 7.4, the bicarbonate ion to carbonic acid concentration is 20:1. **This cannot protect against pH changes due to respiratory problems. |
What is not scientific nomenclature of the carbonic acid-bicarbonate buffer system. | CO2 + HO2 <--> H2CO3 <--> Hydrogen + HCO3-. |
Describe the phosphate buffer system. | Most important intracellular, but also buffers in the urine. |
Describe renal control buffer system. | Excretion of hydrogen in urine is the only way to eliminate huge excess. Kidneys make bicarbonate and save filtered bicarbonate. |
What are the normal values of the acid base balance? | pH 7.35 - 7.45. PCO2 35-45 mmHg. PO2 80-100 mmHg. HCO3 22-28 mEq/L. |
What do acid base imbalances present as? | Acidosis: depression of CNS - coma. Alkalosis: excitability of nervous tissue (spasms, convulsions, death). |
What causes respiratory acidosis/alkalosis? | Changes in the partial pressure of CO2. >45 mmHg = acidosis. <35 mmHg = alkalosis. |
What causes metabolic acidosis/alkalosis? | Changes in bicarbonate ion (HCO3-). <22 mEq/L = acidosis. > 28 mEq/L = alkalosis. |
Describe respiratory acidosis. | Elevation of CO2. Due to lack of removal of CO2 from blood. Treatment: Ventilate. |
Describe respiratory alkalosis. | Arterial CO2 is low. Renal compensation involves decrease of hydrogen excretion and increase reabsorption of bicarbonate. Treatment: breath into paper bag. |
Describe metabolic acidosis. | Blood bicarbonate is low. Loss by diarrhea or kidney dysfunction. Increase acid from diet/diabetes. Kidney fails to remove excess hydrogen from protein metabolism. Treatment: ventilate and correct the cause. |
Describe metabolic alkalosis. | Blood bicarbonate is high. Cause is a non-respiratory loss of acid (vomit, diuretics, dehydration, intake of alkali drugs). Hypoventilation. Treatment: fluid and electrolyte therapy, correct the cause. |
Define milliequivalent. | grams of solute in one mL of solution. |
What are the two fluid compartments? | Intracellular. Extracellular. |
Describe Extracellular. | 1/3 intravascular. 2/3 interstitial. |
Describe the movement between fluid compartments. | Intracellular to Interstitial: by diffusion. Intravascular to interstitial: by hydrostatic pressure. |
Define osmosis. | Movement of water from high to low concentration. |
Define hydrostatic pressure. | Pressure exerted by the movement or mass of water. |
Describe isotonic. | solutions are equal on opposite sides of membrane. Red blood cell is normal. |
Describe hypertonic. | Solute is greater on one side of membrane. Red blood cell shrinks. |
Describe hypotonic. | Solute is lesser on one side of membrane. Red blood cell bursts. |
Describe dehydration. | Loss of total body water.
Isotonic: salt and water lost is equal (diarrhea, bleeding). Hyponatremic: loss of sodium (sweat, diuretics). Hypernatremic: increased sodium (high sodium diet). |
Describe the regulatory mechanism for fluid. | Thirst. Autonomic Nervous System: sympathetic response. Hormonal response: antidiuretic hormone, renin-angiotensin-aldosterone. |
Describe the antidiuretic hormone. | Stimulated by high osmotic pressure in hypothalamic osmoreceptors. |