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Lizard and Snake Cardiovascular Physiology (view source)
Revision as of 17:05, 1 March 2010
, 17:05, 1 March 2010no edit summary
*'''Heart rate''' - The heart rate of reptiles is dependent upon numerous variables including body temperature, body size, respiratory rate and sensory stimulation. Based on allometric scaling of bodyweight a simple formula for heart rate is 33.4kg-0.25. Reptiles that are warming up in the morning have higher heart rates than those cooling down later in the day.
*'''Heart rate''' - The heart rate of reptiles is dependent upon numerous variables including body temperature, body size, respiratory rate and sensory stimulation. Based on allometric scaling of bodyweight a simple formula for heart rate is 33.4kg-0.25. Reptiles that are warming up in the morning have higher heart rates than those cooling down later in the day.
* The heart is under neuroendocrine control, with the vagal parasympathetic (cholinergic) innervation being the principle mode of neural modulation of chronotopy and inotropy in reptiles.
* The sympathetic nervous system exerts mild excitatory adrenergic control but non-adrenergic non-cholinergic systems (NANC) may also contribute to cardiovascular control.
* The renin-angiotensin system and counter-regulatory natriuretic peptides appear to play a part in cardiovascular physiology of reptiles (Uva and Vallarino, 1982; Chiu ''et al''., 1986; Breno ''et al''., 2001).