Open-Book Quiz, Chapter 39
Three uses of diuretics include treatment of hypertension, mobilization of edematous fluid, and used to prevent renal failure.
Aldosterone is the principal mineralocorticoid of the adrenal cortex; it stimulates reabsorption of sodium from the distal cortex.
Most diuretics share the same basic mechanism of action: they block sodium and chloride reabsorption. The greatest diuresis is produced by those drugs whose site of action is early in the nephron.
Adverse effects caused by diuretics on the extracellular fluid include hypovolemia, acid-base imbalance, and disturbance of elytrolite levels.
The four major categories of diuretic drugs include loop diuretics, thiazide diuretics, osmotic diuretics, and potassium-sparing diuretics.
Situations that require rapid or massive mobilization of fluid are usually treated with furosemide.
The most widely used thiazide diuretic is hydorchlorothiazide, whose primary indication for use is hypertension.
The potassium-sparing diuretics have recently been found to have a positive impact on the treatment of severe heart failure.
Mannitol promotes diuresis by creating an osmotic force within the lumen of the nephron.
Patients who should use thiazide diuretics with caution include cardiovascular disease, renal impairment, diabetics mellitus, history of gout, those taking digoxin lithium, or antihypertensive drugs. Also, generally avoid use in women who are pregnant or breast-feeding.
Agents Affecting the Volume and Ion Content of Body Fluids
Open-Book Quiz, Chapter 40
Maintenance of fluid volume and osmolality is primarily the job of the kidneys.
Volume contraction is defined as a decrease in total body water; volume expansion is defined as increase in total body water.
Normal plasma sodium content is 135 to 145 mEq/L.
When a patient experiences a decrease in the total volume of extracellular fluid, and there is no change in osmolality, the situation is referred to as isotonic contraction.
A patient with lack of aldosterone is most likely to develop which disorder of fluid volume and osmolality? Hypotonic contraction
Use of which drug is most likely to cause respiratory alkalosis? Aspirin and other salicylates
In most cases, metabolic alkalosis can be corrected by infusing a solution of sodium chloride and potassium chloride.
In the presence of extracellular alkalosis, potassium uptake by cells is enhanced, causing a reduction in extracellular potassium levels. Extracellular acidosis promotes the exit of potassium from cells, thereby causing extracellular hyperkalemia.
Symptoms of mild intoxication of magnesium include muscle weakness, hypotension, sedation, and EKG changes. At higher concentrations, cardiac arrest are seen
IV solutions of potassium chloride must be diluted to 40 mEq/L or less and infused slowly.
Review of Hemodynamics
Open-Book Quiz, Chapter 41
Functions of the circulatory system include delivery of oxygen, nutrients, hormones, electrolytes and other essentials to cells. Also the removal of carbon dioxide, metabolic waste and other detritus from cells. In addition, the system helps fight infection.
Arterioles are control valves that regulate local blood flow, capillaries are the sites for exchange of fluid, oxygen, carbon dioxide, nutrients, hormones, wastes, and so forth, and venules collect blood form the capillaries.
Resistance to blood flow is determined by diameter and length of vessel.
What is the most important factor that determines how blood gets back to the heart? Auxillary veinous pump.
Stroke volume is determined by myocardial contractility, cardiac afterload, and cardiac preload.
Preload is formally defined as the amount of tension applied to a muscle prior to contraction.
What are the effects of sympathetic...
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