Rommel S A, Pabst D A, McLellan W A
National Museum of Natural History, Smithsonian Institution, Washington, D.C.
Anat Rec. 1993 Dec;237(4):538-46. doi: 10.1002/ar.1092370414.
The cetacean reproductive system is surrounded by thermogenic locomotory muscle and insulating blubber. This arrangement suggests elevated temperatures at the uterus that could induce detrimental effects on fetal development. We present anatomical evidence for a complex countercurrent heat exchange system that could function to regulate the thermal environment of the uterus and a developing fetus. Cooled venous blood from the surfaces of the dorsal fin and flukes enters the abdominal cavity via the lumbo-caudal venous plexus. This plexus is juxtaposed to the arterial and venous plexuses associated with the uterus. The morphology of the lumbo-caudal venous plexus suggests that it acts as a "heat sink" for the adjacent tissues. Heat may be transferred to the cool, lumbo-caudal venous plexus from the warm blood in the arterial and venous plexuses supplying the uterus. Heat may also be transferred from adjacent locomotory muscles to the cool lumbo-caudal venous plexus. The countercurrent heat exchanger created by the juxtaposition of the lumbo-caudal venous plexus with the uterovarian arterial plexus is similar in design to that of the countercurrent heat exchanger described for male cetaceans. The functional implications of introducing cool superficial blood into the abdominal cavity of a diving, and locomoting female cetacean are discussed.
鲸类动物的生殖系统被产热的运动肌肉和隔热的鲸脂所包围。这种结构表明子宫处温度升高，可能会对胎儿发育产生不利影响。我们提供了解剖学证据，证明存在一个复杂的逆流热交换系统，该系统可能起到调节子宫和发育中胎儿热环境的作用。来自背鳍和尾鳍表面的冷却静脉血通过腰尾静脉丛进入腹腔。这个静脉丛与子宫相关的动脉和静脉丛相邻。腰尾静脉丛的形态表明它充当了相邻组织的“散热器”。热量可能从供应子宫的动脉和静脉丛中的温血传递到凉爽的腰尾静脉丛。热量也可能从相邻的运动肌肉传递到凉爽的腰尾静脉丛。腰尾静脉丛与子宫卵巢动脉丛并列形成的逆流热交换器，其设计与描述的雄性鲸类动物的逆流热交换器相似。本文讨论了将凉爽的体表血液引入正在潜水和运动的雌性鲸类动物腹腔的功能意义。
