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Tag Archives: ADH

Regulation of Water Excretion

23-Jul-16

Water excretion, as with sodium excretion, is regulated in partnership with the CV system. Central goals in regulating both salt and water excretion are to: 1).preserve vascular volume and 2).maintain plasma osmolality at a level that is healthy for tissue cells. The main regulators of water excretion, not surprisingly, relate to osmolality and volume. Quantitatively, […]

Regulation of Sodium Excretion

25-Jun-16

Percentage of Sodium Reabsorbed The Goals of Regulation The overriding goals of regulating sodium and water excretion are to support the requirements of the cardiovascular system. This is manifested in 3 ways: 1.the kidneys maintain a sufficient ECF volume to fill the vascular space (mean circulatory filling pressure); 2.keep the osmolality of the ECF at a level […]

Urinary Concentration – The Medullary Osmotic Gradient

22-Jun-16

The kidneys can produce a range of urine osmolalities depending on the levels of ADH. The production of hypo-osmotic urine is an understandable process: The tubules (particularly the thick ascending limb of Henle's loop) reabsorb relatively more solute than water, and the dilute fluid that remains in the lumen is excreted. The production of hyperosmotic […]

Physiologic Adapations and Maladaptations in Heart Failure

20-Oct-15

Basic Concepts Preload The concept of preload in the intact heart was described by physiologists Frank and Starling a century ago. The preload can be though of as the amount of myocardial stretch at the end of diastole, just before contraction. Measurements that correlate with myocardial stretch, and that are often used to indicate the […]

The Regular of Extracellular Fluids – ADH Secretion and Renin-Angiotensin System

09-Mar-14

The volume of ECF is determined primarily by the total amount of osmotically active solute in the ECF. Excessive loss of Na+┬áin the stools (diarrhea), urine (severe acidosis, adrenal insufficiency), or sweat (heat prostration) decreases ECF volume markedly and eventually leads to shock. The regular of extracellular fluids is based on vasopressin (ADH) and renin-angiotensin […]