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OverviewMany mammalian species living at medium or higher latitudes show marked annual cycles in various morphological and functional properties. There is a clear cycle of the reproductive activity ranging from a fertile to an infertile state in both the male and female. Such an annual periodicity can be regarded as an adaptation to seasonal changes of environmental conditions such as cli mate and nutrition, ensuring that birth and development of the litter are re stricted to a favorable season. These annual cycles consist of cyclic changes of exocrine and endocrine gonadal function, in the hormone-dependent organs (accessory glands, etc.) and in the hormonal hypothalamic-pituitary-gonadal system (for literature, see Hoffmann 1981). Such a seasonal cycle of reproductive activity was found in species from all vertebrate groups (i.e., birds, see Hoffmann 1981; Breucker 1982; reptiles, amphibians, and teleosts, see Hoffmann 1981). In those primate species of the Macaca family which are seasonal breeders (Zamboni et al. 1974), it was demonstrated by Richter et al. (1978) and Wickings and Nieschlag (1980) that these cycles are also evident under constant laboratory conditions, suggest ing that these cycles are based upon endogenous rhythms which are modulated and synchronized in the natural habitat by exogenous factors. Full Product DetailsAuthor: Martin BergmannPublisher: Springer-Verlag Berlin and Heidelberg GmbH & Co. KG Imprint: Springer-Verlag Berlin and Heidelberg GmbH & Co. K Volume: 105 Dimensions: Width: 17.00cm , Height: 0.40cm , Length: 24.40cm Weight: 0.195kg ISBN: 9783540175834ISBN 10: 3540175830 Pages: 76 Publication Date: 30 April 1987 Audience: College/higher education , Professional and scholarly , Undergraduate , Postgraduate, Research & Scholarly Format: Paperback Publisher's Status: Active Availability: Out of stock  The supplier is temporarily out of stock of this item. It will be ordered for you on backorder and shipped when it becomes available. Table of Contents1 Introduction.- 2 Material and Methods.- 2.1 Groups of Animals.- 2.2 Preparation.- 3 Results.- 3.1 Testicular Histology in Long Photoperiods.- 3.2 Process of Involution.- 3.3 Morphological Changes Depending on the Phases of Involution.- 4 Discussion.- 4.1 Process of Involution.- 4.2 Sertoli Cells.- 4.3 Blood-Testis Barrier.- 4.4 Leydig Cells.- 5 Conclusions.- 6 Summary.- Acknowledgements.- References.ReviewsAuthor InformationTab Content 6Author Website:Countries AvailableAll regions |
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