多长的四肢可以减轻长鹿心脏的能量负担
Roger S Seymour1, Edward P Snelling2
1School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia.
The Journal of experimental biology
|September 30, 2025
概括
长鹿具有异常高血压 (MAP),以支它们的长子. 然而,它们的长四肢有助于提升心脏,降低血液循环的能源成本.
科学领域:
- 身体生理学 身体生理学
- 生物力学 生物力学
- 脊椎动物动物学 脊椎动物动物学
背景情况:
- 成年长鹿的平均动脉血压 (MAP) 为200-250mmHg,是大多数哺乳动物的两倍多.
- 这种高的MAP是必要的,以克服由他们的长造成的水静压梯度,头部位于心脏上方.
研究的目的:
- 为了量化高MAP对长鹿心脏的能量负担.
- 探索四肢和部进化如何影响心血管能量消耗.
主要方法:
- 开发了一个数值模型来模拟左心室在不同心脏位置下的能量消耗.
- 对一只固定高度的长鹿进行了计算,改变了心脏的垂直位置.
主要成果:
- 左心室的能量消耗约为长鹿的休息代谢率的16%,相比之下,类似大小的哺乳动物的子较短的能量消耗为9%.
- 如果高度仅通过子延长而演变,估计的能源成本将是21%.
结论:
- 长四肢的进化,早于长子,提高了长鹿的心脏,减少了所需的MAP,并节省了大量的能量.
- 在长鹿中,心脏和头之间的垂直距离代表了陆地脊椎动物的最大进化适应.
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