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核心技术专利：CN118964589B侵权必究

核心技术专利：CN118964589B侵权必究

Seymour R S, Johansen K

Department of Zoology, University of Adelaide, South Australia.

Comp Biochem Physiol A Comp Physiol. 1987;88(2):167-70. doi: 10.1016/0300-9629(87)90465-8.

Despite the continuity of the circulatory system, blood flowing down the veins of the neck does not assist blood flowing up the arteries. Because of collapsible veins, gravitational pressure gradients are not matched in arterial and venous sides of circulatory loops above the heart as would be necessary for a siphon to operate. 2. All animals have arterial blood pressures capable of lifting the blood to the head without the assistance from a siphon. In cases of longer vertical distances, such as in giraffes and climbing snakes, the heart does more work against the effects of gravity on the arterial blood column. 3. The potential energy of the blood in the head is lost as frictional heat produced in the veins.

尽管循环系统是连续的，但沿颈部静脉向下流动的血液并不能辅助沿动脉向上流动的血液。由于静脉可塌陷，心脏上方循环回路的动脉侧和静脉侧的重力压力梯度并不匹配，而虹吸管运作需要这种匹配。2. 所有动物的动脉血压都能够在没有虹吸管辅助的情况下将血液提升至头部。在垂直距离较长的情况下，比如长颈鹿和攀爬中的蛇，心脏需要做更多工作来克服重力对动脉血柱的影响。3. 头部血液的势能在静脉中产生的摩擦热中损失掉了。

Seymour R S, Johansen K

Department of Zoology, University of Adelaide, South Australia.

Comp Biochem Physiol A Comp Physiol. 1987;88(2):167-70. doi: 10.1016/0300-9629(87)90465-8.

Despite the continuity of the circulatory system, blood flowing down the veins of the neck does not assist blood flowing up the arteries. Because of collapsible veins, gravitational pressure gradients are not matched in arterial and venous sides of circulatory loops above the heart as would be necessary for a siphon to operate. 2. All animals have arterial blood pressures capable of lifting the blood to the head without the assistance from a siphon. In cases of longer vertical distances, such as in giraffes and climbing snakes, the heart does more work against the effects of gravity on the arterial blood column. 3. The potential energy of the blood in the head is lost as frictional heat produced in the veins.

尽管循环系统是连续的，但沿颈部静脉向下流动的血液并不能辅助沿动脉向上流动的血液。由于静脉可塌陷，心脏上方循环回路的动脉侧和静脉侧的重力压力梯度并不匹配，而虹吸管运作需要这种匹配。2. 所有动物的动脉血压都能够在没有虹吸管辅助的情况下将血液提升至头部。在垂直距离较长的情况下，比如长颈鹿和攀爬中的蛇，心脏需要做更多工作来克服重力对动脉血柱的影响。3. 头部血液的势能在静脉中产生的摩擦热中损失掉了。