Week 3: Electrolytes Na+ and H2O (Dr. Zhang)

total body water is distributed primarily into two compartments which are

ICF osmolality is primarily determined by the concentration of potassium and its accompanying anions (mostly organic and inorganic phosphates).

Sodium and its accompanying anions (chloride and bicarbonate) comprise more than 90% of the total osmolality of the ECF;

most cell membranes are freely permeable to water, thus the osmolalaties of ICF and ECF are equal

true

(e.g., 0.9% sodium chloride [NaCl] solution) to the ECF will result in no change in intracellular volume because there will be no change in the effective ECF osmolality is what

isotonic

e.g., 3% NaCl) to the ECF will result in a decrease in ICF (cell) volume is what

hypertonic solution

e.g., 0.45% NaCl) to the ECF will result in an increase in cell volume is what

hypotonic solution

The ECF concentration of effective osmoles determines its tonicity, which directly affects the distribution of water between the extra- and intracellular compartments.

true

Plasma osmolality is primarily determined by the sodium concentration, but serum glucose and blood urea nitrogen (BUN) may contribute

true

what is commonly known as antidiuretic hormone (ADH), is synthesized in the hypothalamus and released from the posterior pituitary as a result of both osmotic and nonosmotic regulators.

arginine vasopressin

how do the following change in heart failure patient

1)Extracellular Fluid volume

2)Interstitial fluid volume

3)Arterial volume

what is the level for hypenatremia

higher than 145mEq/L

what is the level for hyponatremia

lower than 135 mEq/L

          1a. Hypovolemic hypernatremia, decreased ECF volume

          1b. Euvolemic (isovolemic) hypernatremia, normal ECF volume

          1c. Hypervolemic Hypernatremia, increased ECF volume

hypernatremia

         2a. Hypertonic hyponatremia

         2b. Hypotonic hyponatremia

           2b1.  Hypovolemic Hypotonic Hyponatremia, decreased ECF volume

           2b2.  Euvolemic (isovolemic) hypotonic hyponatremia, normal ECF volume

           2b3.  Hypervolemic Hypotonic Hyponatremia, increased ECF volume

hyponatremia

is always associated with hypertonicity and cellular dehydration, resulting from a deficit of water relative to ECF sodium content.

hypernatremia

most often results from water loss by either renal or extrarenalmechanisms. Less commonly, hypernatremia can result from administration of hypertonic fluids or excess sodium ingestion.

hypernatremia

what develops when the net result of these effects is the loss of more sodium than water.

hyponatremia

a.blocks sodium reabsorption in the distal tubules in renal cortex , increases sodium and water removal from the body.

b.decreases in effective arterial volume stimulates ADH release,

c.ADH increases free water reabsorption in the collecting duct,

d.increases water intake because of stimulation of thirst

thiazide diuretics

what causes more severe hyponatremia than loop diuretics

thiazides diuretics

The most common causes of SIADH include tumors such as small cell lung or pancreatic cancer, CNS disorders (e.g., head trauma, stroke, meningitis, pituitary surgery), and pulmonary disease (e.g., tuberculosis, pneumonia, acute respiratory distress syndrome).

true

what is associated with ECF volume expansion occurs in conditions in which the kidney’s sodium and water excretion are impaired.

hyponatremia

Patients with cirrhosis, HF, or nephrotic syndrome have an expanded ECF volume and edema, but a decreased effective arterial blood volume (EABV).

true