Rommel S A, Early G A, Matassa K A, Pabst D A, McLellan W A
Marine Mammal Program, U. S. National Museum of Natural History, Washington, DC, USA.
Anat Rec. 1995 Nov;243(3):390-402. doi: 10.1002/ar.1092430314.
Seal reproductive systems are surrounded by thermogenic muscle and insulating blubber, suggesting elevated temperatures at the gonads and uterus. In the limbs of terrestrial mammals, cooled blood returning from superficial veins is mixed proximally with warm blood returning from deep veins. Thus, mixed cool-superficial and warm-deep venous blood from the hind limbs is returned to the central circulation.
We describe structures observed in salvaged carcasses of harbor (Phoca vitulina), gray (Haliochoerus gryphus), harp (Phoca groendlandica), hooded (Cystophora cristata), and ringed (Phoca hispida) seals. Vessels were identified by dissection of injected and uninjected material.
In contrast to terrestrial mammals, phocid seals have anastomoses between the veins of the distal hind limb and the pelvis which allow large volumes of cool blood returning from the skin surface of the flipper to enter the gluteal, pelvic, or pudendo-epigastric veins. This provides a cool-superficial venous return that remains separate from the warm-deep venous return of the femoral veins. The cooled venous blood from the hind flippers supplies venous plexuses lining the inguinal region and the abdominal and pelvic cavities.
Cooled blood may prevent hyperthermic insult to seal reproductive systems.
海豹的生殖系统被产热肌肉和绝缘脂肪所包围，这表明性腺和子宫处温度较高。在陆生哺乳动物的四肢中，从浅表静脉回流的冷却血液在近端与从深部静脉回流的温暖血液混合。因此，来自后肢的混合了冷的浅表静脉血和温暖的深部静脉血会回流到体循环。
我们描述了在港海豹（斑海豹）、灰海豹、竖琴海豹、冠海豹和环斑海豹的打捞尸体中观察到的结构。通过解剖注射和未注射材料来识别血管。
与陆生哺乳动物不同，海豹科海豹后肢远端静脉与骨盆静脉之间存在吻合，这使得从鳍状肢皮肤表面回流的大量冷却血液能够进入臀静脉、盆腔静脉或阴部 - 腹壁静脉。这提供了一条与股静脉温暖的深部静脉回流分开的冷的浅表静脉回流路径。来自后鳍状肢的冷却静脉血为腹股沟区域以及腹腔和盆腔内衬的静脉丛供血。
冷却的血液可能会防止过热对海豹生殖系统造成损伤。
