These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Functional morphology of the avian medullary cone.
    Author: Casotti G, Lindberg KK, Braun EJ.
    Journal: Am J Physiol Regul Integr Comp Physiol; 2000 Nov; 279(5):R1722-30. PubMed ID: 11049855.
    Abstract:
    The organization of the renal medulla of the Gambel's quail, Callipepla gambelii, kidney was examined to determine the number of loops of Henle and collecting ducts and the surface area occupied by the different nephron segments as a function of distance down the medullary cones. Eleven medullary cones were dissected from the kidneys of four birds, and the tissue was processed and sectioned for light microscopy. In addition, individual nephrons were isolated on which total loop thin descending segment and thick prebend segment lengths were measured. The results show no correlation between the absolute number of loops of Henle and the length of the medullary cones. The number of thick and thin limbs of Henle and collecting ducts decrease exponentially with distance toward the apex of the cones and the rate of decrease is similar for cones of different lengths. Initially there is a rapid decrease in the number of thin limbs of Henle, indicating that most nephrons do not penetrate the cones a great distance. Thick descending limbs of Henle (prebend segment) ranged in length from 50 to 770 microm, and there was little correlation with the total length of the loop of Henle. However, the length of the thin limb of Henle correlated well with total loop length. The cell surface areas of the limbs of the loop of Henle and the collecting ducts decreased toward the apex of the cones.
    [Abstract] [Full Text] [Related] [New Search]