ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Entry of nephrons into the collecting duct network of the avian kidney: A comparison of chickens and desert quail (1993)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 216 (1993), S. 259-269 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The avian kidney contains a population of nephrons with and without loops of Henle. How the collecting ducts of this heterogeneous population of nephrons merge to exit as single ducts from the medullary cones has been uncertain. The results of this study show that the collecting duct tree begins with the coalescence of the distal tubules of pairs of loopless nephrons. These primary collecting ducts receive output from only loopless nephrons. Primary collecting ducts fuse in pairs and become secondary collecting ducts. They receive the distal tubules of transition nephrons. Pairs of secondary collecting ducts fuse and become tertiary collecting ducts. Tertiary collecting ducts receive the distal tubules of looped nephrons. Thus, the fluid from all nephron types comingles as it passes through the medullary cone. The results of this study also show that the anatomical arrangement of medullary cones does not permit the output from one medullary cone to enter a second medullary cone. Thus, all the medullary cones function as parallel units. This anatomical organization of the avian kidney affects its ability to produce a urine hyperosmotic to the plasma. © 1993 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052160303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Proportions of mammalian-type and reptilian-type nephrons in the kidneys of two passerine birds (1986)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 187 (1986), S. 173-179 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We compared the proportions of mammalian-type and reptilian-type nephrons in the kidneys of two species of passerine birds. The desert house sparrow (Passer domesticus) is relatively well adapted for water conservation, whereas the white-crowned sparrow (Zonotrichia leucophrys) is more mesic adapted. The two species do not differ in body mass, but the kidneys of P. domesticus are significantly smaller than those of Z. leucophrys. Associated with its smaller size, the house sparrow kidney has significantly fewer glomeruli (35,700 per kidney) than does the white-crowned sparrow kidney (53,000 per kidney). The medullary cones, which contain the loops of Henle of the mammalian-type nephrons, are significantly longer in house sparrows than in white-crowned sparrows (2.2 vs. 1.9 mm). The number of medullary cones, the number of nephrons per medullary cone, and, hence, the number of mammalian-type nephrons do not differ between the two species. The smaller number of nephrons in the kidney of the house sparrow therefore represents a smaller number of reptilian-type nephrons. Desert house sparrows have 18% mammalian-type nephrons, whereas white-crowned sparrows have 10% mammaliantype nephrons. The relative reduction of reptilian-type nephrons in P. domesticus may reduce the flow of dilute urine through the collecting ducts, thereby permitting a greater concentration gradient to be established along the length of the medullary cones.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051870205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Structure of the glomerular capillaries of the domestic chicken and desert quail (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995), S. 57-63 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The glomerular capillary architecture of nephrons that include a loop of Henle (looped) and those that lack the loop (loopless) nephrons was examined qualitatively and quantitatively by electron microscopy in Gallus gallus and Callipepla gambelii. The glomerular capillaries of looped nephrons form a dichotomously branched network, while those of loopless nephrons are arranged loosely, and the majority are unbranched. There was no significant difference in the diameter of the glomerular capillaries between looped and loopless nephrons; however, in all cases the diameter of the afferent arteriole was significantly larger than that of the efferent arteriole. Based on size alone, the predicted blood flow rate in the efferent arteriole in 20% that of the afferent arteriole in G. gallus and 7% that of the afferent arteriole in C. gambelii. There was no significant difference in the volume density (Vv) of the glomerular capillaries between looped and loopless nephrons. However, the surface area density (Sv) of the glomerular capillaries in loopless nephrons of C. gambelii was significantly larger than for the looped nephrons, and for the loopless nephrons in G. gallus. This suggests that there may be a decrease in blood flow rate along the glomerular capillaries of the loopless nephrons in C. gambelii. Overall, the results indicate that the avian glomerular capillaries are less complex than those of mammals. Reasons may be that either avian blood is more viscous than that of mammals or that avian erythrocytes may be unable to fit physically through a tight intertwining network of capillaries due to the presence of a nucleus, which limits the tank-treading ability of avian erythrocytes. © 1995 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052240107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Contributions of the kidneys and intestines to water conservation, and plasma levels of antidiuretic hormone, during dehydration in house sparrows (Passer domesticus) (1988)
    Springer
    Journal of comparative physiology 158 (1988), S. 353-361 
    Details
    ISSN: 1432-136X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The contributions of the kidneys, the small intestine and the lower intestine (rectum plus cloaca) to water conservation during dehydration in unanaesthetized, unrestrained house sparrows (Passer domesticus) were assessed. Thirty hours of acute dehydration resulted in a 12% loss in body mass and a significant increase in plasma osmolality. Glomerular filtration rate declined by 55%, from 7.7 to 3.5 ml/h, and urine flow rate delined by more than 80%, from 0.2 to 0.03 ml/h. These changes are likely attributable to a large increase in plasma levels of arginine vasotocin during dehydration, from 〈26 pg/ml in hydrated birds to greater than 200 pg/ml after 30 h dehydration. Flow of water from the ileum to the lower intestine was reduced during dehydration, primarily because of a reduced flow of dry matter (with no significant reduction in water content). The rate of water loss in the excreta declined from 0.2 ml/h in hydrated birds to 0.04 ml/h in dehydrated birds. The rate of water reabsorption in the lower intestine (equal to the rate of water loss in the excreta minus the combined rates of inflow into the lower intestine from the urine and the ileal contents) slightly exceeded the rate of water flow from the ileum in both hydrated and dehydrated birds. We suggest that much of the water reabsorbed in the lower intestine of hydrated birds derives from the urine, but that primarily water from ileal contents is reabsorbed in dehydrated birds. That is, urine undergoes significant post-renal modification in hydrated but not dehydrated house sparrows.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695334
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Morphometry of the galliform cecum: A comparison between Gambel's quail and the domestic fowl (1990)
    Springer
    Cell & tissue research 259 (1990), S. 511-518 
    Details
    ISSN: 1432-0878
    Keywords: Cecum ; Morphometry ; Absorption ; Domestic fowl (Aves, Phasianiformes) ; Callipepla gambelii (Aves, Galliformes)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Tissues from the proximal, middle, and distal regions of the ceca of Gambel's quail and domestic fowl were examined by scanning and transmission electron microscopy. Cellular and subcellular structures, including epithelial cell height, mitochondrial volume fraction, microvillous surface area, proportion of goblet cells, and junctional complex characteristics, were quantified by a variety of stereologic procedures and other measurement techniques. The mucosal surface of quail cecum shows a much more highly developed pattern of villous ridges and flat areas than that of fowl cecum. The fowl has significantly greater cell heights than the quail in all cecal regions. The mitochondrial volume fraction does not differ significantly with species or region, but mitochondria are concentrated on the apical side of the nucleus. In both species, the proximal cecal region has the greatest microvillous surface area. All 3 components of junctional complexes, including zonula occludens, zonula adhaerens, and macula adhaerens, are quantified. When all factors are considered, the quail cecum appears to have morphological characteristics consistent with a greater potential capacity for absorption than the fowl cecum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01740778
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Microanatomy of the renal cortex in the domestic fowl (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 249-267 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Two aspects of the avian renal cortical microanatomy previously were unclear. The precise in situ folding patterns and orientations of the nephrons with respect to the other cortical elements had not been demonstrated. It also was not known whether certain nephron segments are supplied exclusively by either the arterial or the portal blood flow. In the present study, a new casting compound was developed to allow selective examination of the cortical components by light microscopy. Cortical nephrons at the surface of the kidney were serially sectioned and reconstructed in order to determine: (a) their relationships to the vasculature and collecting ducts; (b) the location and characteristics of the tubule segments; and (c) the primary and secondary folding patterns of the tubules. The anatomical findings were documented individually and then summarized in a comprehensive diagram of the superficial cortical microanatomy. In addition, an in vivo method was used to determine the extent of portal blood distribution to the nephron segments. It was demonstrated that renal portal blood suffuses all of the segments except for the loops of Henle.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051680302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    facet.materialart.
    Unknown
    Morphometry of the galliform cecum: A comparison between Gambel's quail and the domestic fowl (1990)
    Springer
    Details
    Publication Date: 1990-10-01
    Print ISSN: 0302-766X
    Electronic ISSN: 1432-0878
    Topics: Biology , Medicine
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...