. Bonner zoologische Monographien. Zoology. 50 and 34° C), and in birds between 1° and ° C (Chew et al. 1967, Hock I960, Hudson 1969, MacMillen 1965, Raths 1975). Arousal: Arousal from torpor at low Ta involves an enormous thermo- regulatory stress. Activation of the sympathetic system leads immediately to a doubling of the cardiac frequency, to an abdominal vasoconstriction and to a mobilization of brown fat (bats: Kallen 1960, Kulzer 1967, Mejsnar and Jansky 1970, Rauch 1973). However, anatomically, the sympathetic system in bats shows no special features (Webber and Kallen 1968). In- cr
. Bonner zoologische Monographien. Zoology. 50 and 34° C), and in birds between 1° and ° C (Chew et al. 1967, Hock I960, Hudson 1969, MacMillen 1965, Raths 1975). Arousal: Arousal from torpor at low Ta involves an enormous thermo- regulatory stress. Activation of the sympathetic system leads immediately to a doubling of the cardiac frequency, to an abdominal vasoconstriction and to a mobilization of brown fat (bats: Kallen 1960, Kulzer 1967, Mejsnar and Jansky 1970, Rauch 1973). However, anatomically, the sympathetic system in bats shows no special features (Webber and Kallen 1968). In- creasing blood flow to the brown fat is probably the primary cause of the. 0 12 3 hours U Fig. 29: Increase of Tb during arousal from hibernation; anterior (a) Tb of head or chest, posterior (p) rectal temperature. Ta (except in the bat Nyctalus) between °—6° C. Nn = Nyctalus noctula (Kulzer 1969), El = Eliomys quercinus (Ambid 1971) , Ta = Tamias striatus (Wang and Hudson 1971), Me = Mesocricetus auratus (Lyman 1948), Ci = Citellus undulatus (Feist and Galster 1974), Cr = Cricetas cricetus (Raths unpubl.). differential regional blood distribution between the anterior and posterior parts of the body, and the faster warming of the anterior part compared to the posterior (Rauch 1973). In arousing chipmunks (Wang and Hudson 1971) and in several aestivators (Bartholomew and Hudson 1960, Hudson et al. 1972) , the anterior-posterior temperature gradient is absent. The speedy increase in metabolism during arousal is only possible by a general activation of the endocrine system and by the removal of the inhibition of many enzymes (Zimny and Clement 1961). In this manner, oxydative metabolism increases (Hammel et al. 1968, Wang and Hudson 1971), but simultaneously there is a burst of glycolysis (Ferdmann and. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustration
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Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksubjectzoology
