Carotid Haemodynamics in the Giraffe
In a research letter to this journal on the physiology of the giraffe, McCalden et al. suggested that cranial blood flow in the giraffe is regulated by an autoregulatory response of the cranial vasculature. Their conclusion was based on two points: 1) that carotid flow remains constant over a wide range of carotid pressures, and 2) that the giraffe exhibits certain postural behaviour. The argument for (2) is that giraffes always remain resting sternally for a few seconds before standing