Author: Meztigar Zule
Country: Somalia
Language: English (Spanish)
Genre: Travel
Published (Last): 3 July 2015
Pages: 41
PDF File Size: 17.80 Mb
ePub File Size: 6.13 Mb
ISBN: 551-6-77801-481-6
Downloads: 71786
Price: Free* [*Free Regsitration Required]
Uploader: Monos

Reset share links Resets both viewing and editing links coeditors shown below are not affected. Rapid onset of severe hyponatraemia causes water to move into cells, which swell. There seems to be no mechanism to protect against hypermagnesaemia, which occurs ba,ance intake is maintained in the face of declining renal function.

Dietary salt content varies considerably and, to maintain sodium balance, excretion must be capable of adjustment to match intake. Water is able to pass freely between these compartments and the distribution of water is therefore determined by osmotic pressure. Renin is a proteolytic enzyme that is released from the juxtaglomerular cells in afferent arterioles of the kidney.

The actions of V1b receptors within the hypothalamus is currently unknown.


Atrial natriuretic peptide This is a polypeptide hormone consisting of 28 amino acids that is synthesized in myocardial cells by cleavage of a precursor pro-ANP. In some disease states the relationship between effective circulating volume and extracellular volume breaks down.

Consider infusion of hypertonic saline. Anti-diuretic hormone, distal flow and potassium excretion Distal potassium excretion is stimulated by ADH.

The results of studies of transplanted patients with renal or cardiac denervation, who hidroelectrolirico, nevertheless, able to maintain normal salt and water balance, have hidroelectrolituco that these mechanisms are not interdependent and that no single receptor is dominant. Comments 0 Please log in to add your comment.


These conditions can promote water retention at the cost of osmoregulation through the hypovolaemic stimulus to ADH as discussed above.

Although plasma osmolality is determined principally by plasma sodium concentration, osmolality is regulated by changes in water balance that bring about dilution or concentration of solute.

More presentations by Dayita Centeno Untitled Prezi. Osmoregulation results in water retention through the action of ADH, returning osmolality to normal but further expanding the extracellular volume. This stimulates ADH secretion and thirst; a fall in renin secretion and aldosterone concentration and a rise in ANP ensue, stimulating increased sodium excretion.

Reduced stretch stimulates the effector response. It is not surprising that the osmoreceptors controlling ADH release are highly sensitive; this is because maintenance of plasma osmolality within a small range is essential to preserve cell volume and thus normal function. Their homeostasis relies on systems that regulate water balance and, as the principal extracellular solute, sodium balance.


Fluid and electrolyte management in the hidroelecrrolitico low birth weight neonate. Publishing platform for digital magazines, interactive publications and online catalogs.

Cancel Reply 0 characters used from the allowed.

Natriuretic peptides Sodium loading results in an appropriate increase in sodium excretion. Control of aldosterone secretion Aldosterone plays a central role in salt balance and potassium excretion. In the absence of ADH, these channels are cleared by endocytosis. Volume regulation overrides osmoregulation. The ventricles and vascular smooth muscle cells have also been shown to produce ANP.


Salt loading expands the extracellular volume, decreasing renin secretion, whereas salt deprivation causes contraction of the extracellular volume, stimulating renin secretion.

Both actions tend to correct hypovolaemia and hypotension, supporting tissue perfusion. Physiological role of the relationship between distal flow and potassium excretion Volume expansion results in decreased activity of the RAS and a decrease in aldosterone-driven potassium secretion, alongside an increase in sodium and water excretion.

This results in increased renal excretion of sodium and water, independent of neural and humoral mechanisms. Renal function in early childhood in very low birthweight infants. Aldosterone has a major role in potassium balance, stimulating potassium secretion from the luminal membrane of the principal cells of the cortical collecting duct. Consequently, maintenance of sodium balance is central to volume regulation.

In examining the systems of salt and volume regulation, it is helpful to consider the concept of the effective circulating volume. Increased water intake driven by thirst, together with water preservation driven by ADH release, returns elevated osmolality to normal or, if it is volume driven, helps to correct volume depletion.