Fisiologia Renal de Vander – Ebook download as PDF File .pdf) or read book online. Conciso e didático, este livro explora os aspectos fundamentais da fisiologia renal que são essenciais para o bom entendimento da medicina clínica. : FISIOLOGIA RENAL DE VANDER 6TA. EDIC. by EATON DOUGLAS C. () by Douglas C. Eaton and a great selection of similar.
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Biology, functions and diseases. Feed-back between geriatric syndromes: As regards the maximum tubular dilution capacity, another of the parameters which Chaimowitz test can evaluate, it has been reported that such dilution is significantly reduced in the very old in comparison with the young: Since uric acid is mainly handled in the proximal tubule, a segment that suffers practically no functional changes with ageing, perhaps flsiologia could explain the above mentioned phenomenon[ 14 ].
Creatinine clearance measured without CC or with cimetidine CCWCwhich is almost the same as inuline clearance due to the blocking effect that cimetidine has on the proximal tubular secretion of creatinine, has proved to be significantly lower in the very old healthy people in comparison to that documented on the younger population[ 12 ]: Fractional excretion of K, Na and Cl following furosemide infusion in healthy, young and very old people. Renal handling of sodium in old people: Combining the latest research with a fully integrated teaching approach, the eighth edition of Vander’s Renal Physiology features revised sections that explain how the kidneys affect other body systems and how they in turn are affected by these systems.
From the clinical point of view, the above mentioned reduction in the tubular capacity to reabsorb sodium fosters sodium depletion and its clinical consequences: Additionally, the high urea urinary excretion documented in the very old could be one of the factors which explains the senile medullar hypotonicity reduced urea medullar content and the nocturia urea osmotic diuresis usually found in the very old patients[ 1516 ].
Additionally, it has also been documented a decrease in sodium reabsorption in the thick ascending loop of Henle in very old healthy people[ 20 ]. The observed difference in the creatinine filtration between the studied age groups could be justified as a consequence of the decrease in the number of glomerular units secondary to their obliteration due to the glomeruloscrerosis which accompanies ageing[ 3 – 5 ].
Since furosemide stimulates sodium loss due to the inhibition of its reabsorption at the level of the TALH, the lower increase in soduria after furosemide infusion in the very old in comparison with the young could be explained by the functional reduction in the TALH furosemide blocking site due to the senescence process[ 23 – 25 ].
Due to the fact that a reduction in the number of urea channels UT1 has been documented in the collecting tubules of very old rats, it could be suggested that the senile increase in urea excretion may be the consequence of a lower reabsorption of urea at the distal tubules[ 17 ].
The collecting tubules are the nephronal segment where potassium secretion, and sodium and water reabsorption take place[ 9 ].
The procurement of a ratio between the CC and the CCWC allows for the evaluation of the net tubular handling of this substance: Journal List World J Nephrol v. The aging kidney in health and disease.
Fisiologia Renal de Vander – Douglas C. Eaton | John P. Pooler – Google Books
The goal of his research is to examine the cellular signaling mechanisms which control all aspects of cellular function including cell growth, division, and responses to external stimuli.
Published online Oct 6. Even nowadays the limits that separate the changes considered typical of the normal ageing process of those patients who suffer from high prevalent illnesses characteristic of this period are not clear.
Creatinine reabsorption by the newborn rabbit kidney. Each chapter is filled with the tools you need to truly learn key concepts rather than merely memorize facts. Aldosterone bioactivity in this segment is studied using the furosemide test, which ultimately generates a discrete hypovolemia that stimulates the release of this hormone, which in turn stimulates the secretion of potassium in the collecting tubules.
The normal ageing kidney—morphology and physiology. This article has been cited by other articles in PMC.
Creatinine, urea, uric acid, water and electrolytes renal handling in the healthy oldest old
This phenomenon can be explained as the decrease in the creatine levels due to the senile diminution in lean body mass tissues from where creatinine comes [ 6 ]. Aging and physiological changes of the kidneys including changes in glomerular filtration rate. Fractional excretion of urea in severely dehydrated elderly with dementia. Additionally, it is important to point out that there are no significant physiological differences related to gender in both age populations.
Examination of kidney function.
Renal reserve in the oldest old. Regarding tubular sodium handling in the oldest old, it has been documented that the selective reabsorption of sodium at the proximal tubule, evaluated using the Chaimowitz test, shows that it remains in the normal range: This has been attributed to the senile medullar hypotonicity[ 324 ].
This increase in the urea urinary excretion, as well as the low protein diet that aged people usually have, both explain the normal serum urea value characteristically found vahders the elderly, despite of their reduced glomerular filtration rate[ 17 ].
Fisiologia Renal de Vander
Rev Esp Geriatr Gerontol. Renal physiology in the oldest old: Clinical consequences[ 13 ]: Tel 91 99 99 Fax 91 21 Besides, it has been documented that free water clearance a marker of TALH function is considerably lower in the very old in comparison with the young: Even though, the ifsiologia mentioned creatinine renal filtration difference between the vandegs groups, there is no significant difference regarding their serum creatinine value between them.
To examine these signaling mechanisms, he uses contemporary methods of cellular and molecular biology including patch voltage clamp methods and expression of cloned signaling molecules in Xenopus oocytes and other expression systems.
This lower local sodium reabsorption, leads to the following alterations[ 8 ]: Anatomical changes in the aging kidney. National Center for Biotechnology InformationU.
Leonardo M. Montes | Universidad de Guanajuato –
Creatinine reabsorption by the aged kidney. On one hand, it has been documented that fractional excretion of urea, in volume contraction as well as in volume expansion, was significantly higher than the one reached by the young: The information obtained by means of the furosemide test senile hyposecretion of potassium explains why the tubular handling of potassium measured as FEK and transtubular potassium gradient: Rennke H, Denker B. Something similar was documented in the newborns but in this case it was attributed to tubular immaturity since this finding disappeared as they grew older[ 89 ].
Renal handling of many substances creatinine, urea, sodium, water, potassium significantly differs between very old healthy people and young one, while there is no change in uric acid renal handling between these groups.
TTKG in basal situation, does not show any significant difference between the very old group and the young one, despite the existence of lower glomerular filtration in the very old, which ultimately accounts for the relatively reduced cation excretion in the very old, since it is known that the potassium excretion tends to increase paralelly to the reduction of glomerular filtration: Physiology of the healthy ageing kidney.