... in the amphibian heart, implying the existence of a stretch–excitation relationship that may explain the variability of cardiac excitation in ectotherms. Amphibia Ventricular myocardium Mapping Activation Stretch Activation of the ventricular myocardium in mammals is governed by the His-Purkinje...

... complex 3D chewing, suggesting that such mechanisms might have evolved early in the tetrapod evolution. Intraoral food processing Feeding Amphibia Kinematics Functional morphology Form and function Food processing refers to any mechanical reduction or preparation of food before...

... a derived processing mechanism where prey items are rasped rhythmically against the dentition on the mouth roof, driven by a loop motion of the tongue. Foraging Manipulation Mastication Tongue Palatal dentition Amphibia Food processing involves any type of mechanical manipulation of food...

... cells amphibia brain thyroid hormones pituitary Mast cells (MC) have been described intracranially, in the dura mater, leptomeninges and choroid plexuses in mammals ( Dropp, 1972 ; Dropp, 1976 ; Theoharides, 1990 ; Michaloudi and Papadopoulos, 1999 ) and birds ( Silverman et al., 1994...

... or structures, which suggests that it belongs to a new class of surfactant protein. * Author for correspondence (e-mail: vmmmelo@ufc.br ) 5 6 2008 © The Company of Biologists Limited 2008 2008 Amphibia Leptodactylus vastus foam nest surfactants frog proteins Many species...

... effective regulation of transcription, which an increase in the level of, e.g. HIF enables, in an environment that approaches the limit of tolerance of the species. * Author for correspondence (e-mail: miknik@utu.fi ) 2 4 2008 © The Company of Biologists Limited 2008 2008 amphibia...

... ) 4 6 2007 © The Company of Biologists Limited 2007 2007 temperature reproduction mitochondria fitness oxygen consumption amphibia Temperature is the most pervasive physical variable affecting biological processes ( Somero, 1997 ). When temperature decreases, enzyme...

... The Company of Biologists Limited 2006 2006 metabolic rate oxygen uptake metamorphosis scaling hypoxia glycogen lactate Amphibia anuran Pseudis paradoxus Early studies on the diffusion and perfusion limitations of cutaneous breathing indicate that routine rates of aerobic metabolism...

... , G. E. and Gans , C. ( 1986 ). Electromyography for Experimentalists . Chicago : University of Chicago Press . 373 pp. Martin , K. M. and Hutchison , V. H. ( 1979 ). Ventilatory activity in Amphiuma tridactylum and Siren lacertina (Amphibia, Caudata) . J. Herpetol...

... activity in Amphiuma. tridactylum and Siren. lacertina (Amphibia, Caudata) . J. Herpetol . 13 , 427 – 434 . 10.2307/1563477 Mcmahon , B. R. ( 1969 ). A functional analysis of aquatic and aerial respiratory movements of an African lungfish, Protopterus. aethiopicus , with reference...

... lymph heart rate under these conditions in Bufo marinus . * e-mail: dan.toews@acadiau.ca . † Present address: Anesthesiology (129), VA Medical Center, 4150 Clement Street, San Francisco, CA 94121, USA. 24 03 1997 © The Company of Biologists Limited 1997 Amphibia...

... most of the year, appears to be positive in July. Since these fluxes do not include dietary calcium, one cannot conclude that feeding frogs are in negative Ca 2+ balance. 29 11 1994 ©The Company of Biologists Limited 1995 active calcium transport Amphibia Rana pipiens frog...

... (Amphibia) . J. Herpetol . 13 , 321 – 327 . 10.2307/1563327 Conklin , R. E. ( 1930 ). The formation and circulation of lymph in the frog. III. The permeability of the capillaries to protein . Am. J. Physiol . 95 , 98 – 110 . 10.1152/ajplegacy.1930.95.1.98 Heisler , N...

... it is an active process involving the distal tendons of the toes. * To whom requests for offprints should be sent. 07 08 1990 © 1991 by Company of Biologists 1991 tree frogs toe pad adhesion detachment climbing Amphibia biomechanics Hyla versicolor Polypedates leucomastyx...

... stimulation and catecholamine administration. It is unlikely that β-adrenoceptors play a significant role in regulating CVR. 19 04 1990 © 1990 by Company of Biologists 1990 sympathetic nerves adrenergic nerves non-adrenergic/non-cholinergic nerves Amphibia adrenoceptors acetylcholine...

... © 1990 by Company of Biologists 1990 toad Amphibia vagus heart autonomic temperature It is well known that heart rate increases with increasing temperature in ectothermic animals. This is in part due to a direct effect of temperature on pacemaker cells ( Clark, 1920 ), but may...

... of Physiology and Biophysics SJ-40, School of Medicine, University of Washington, Seattle, WA 98195, USA. 9 2 1988 © 1988 by Company of Biologists 1988 amphibia blood flow cardiovascular shunting ductus arteriosus hypoxia gill lung metamorphosis pulmonary artery...

... cue ( Phillips, 1985 , 1986 ). migration homing magnetic orientation Amphibia © 1987 by Company of Biologists 1987 11 05 1987 * Present address: Department of Biology, Indiana University, Bloomington, IN 47405, USA. ...

..., 1982 ; Heisler, 1984 b ; for a complete tabulation of data for all orders of animals see Heisler, 1986 b ). acid-base regulation Amphibia blood gases Bufo marinus ΔpH/Δt imidazole alphastat intracellular pH Xenopus laevis © 1987 by Company of Biologists 1987 04 03...

... tension. * Present address: Department of Biology, Dalhousie University, Halifax, Nova Scotia, B3H 4J1, Canada. † Present address: Department of Zoophysiology, University of Aarhus, DK-8000 Aarhus C, Denmark. 25 06 1986 © 1986 by Company of Biologists 1986 Amphibia...