For professional reasons, I have long been fond of the following fact about giraffes. Their heads are so high that their hearts have to produce higher blood pr

For professional reasons, I have long been fond of the following fact about giraffes. Their heads are so high that their hearts have to produce higher blood pressures than any other animal [0]. When they lower their head, a set of valves in the neck restrict the blood flow [1], to prevent the high pressure from damaging its brain. [0] http://news.bbc.co.uk/earth/hi/earth_news/newsid_8368000/8368915.stm http://news.bbc.co.uk/earth/hi/earth_news/newsid_8368000/836... [1] https://www.novartis.com/stories/from-our-labs/giraffes-have-high-blood-pressure-why-dont-they-drop-dead https://www.novartis.com/stories/from-our-labs/giraffes-have...