北京鸭(Anas domestica L.)垂体的血液循环

THE BLOOD SUPPLY OF THE HYPOPHYSIS OF THE PEKING DUCK ANAS DOMESTICA L.

近年来愈来愈多的研究证明,丘脑下部对于腺垂体活动的调节不是神经性的,而是体液性的。普遍的意见认为丘脑下部在中枢神经系统的影响下,产生其种化学介质,通过神经垂体正中隆起部分的神经血管触突,进入门静脉初级毛细血管丛,再经过门静脉到达远侧部,调节促激素的产生和释放。为了证实或反驳这种假说,切断各种受试动物的垂体柄,截断门静脉或阻抑其再生,是经常进行的一种必需手术。

Studies on the sources of blood supply,the formation of the capillary networks andthe venous drainage of the hypophysis of the Peking duck were made on 15 colored gela-tin injected specimens under binocular microscope.It was found that the superior hypophysial arteries were branched off from theoptical artery and the posterior communicating artery of the A.carotis cerebralis.Ac-cording to their origin and distribution the superior hypophysial arteries may be dividedinto anterior and posterior groups.The former supplied the median eminence and parstuberalis while the latter supplied the median eminence,pars tuberalis,infundibularstalk and pars nervosa.The inferior hypophysial arteries,branched off from the A.carotis cerebralis,suppliedboth the pars nervosa and pars distalis.In the median eminence,one superficial and two deep capillary networks werefound.One of the deep capillary network,situated on the lateral wall of the medianeminence was three-dimensioned,and the other located on the floor of the third ventricleunder the ependymal lining,was rather a horizontal plexus.The flat superficial capil-lary network spread over the ventral and lateral surfaces of the median eminence and theinfundibular stalk.Both kinds of the deep capillary networks were in close connection with the ar-terial supply of the hypothalamus,which,however,had its own arterial supply andvenous drainage.Between the deep and superficial capillary networks,few capillaryconnections were found.The infundibular stalk was clearly differentiated from the median eminence by itscharacteristic angioarchitecture.The vascular system of the infundibular stalk consistedof a superficial capillary network,situated orally and aborally,and an internal deep capil-lary network.In its distal end,the internal deep capillary network formed capillaryloops toward its ventricle surface.The above mentioned capillary networks formed portal veins,which,approximately25--50 in number,passed into the pars distalis,thus giving rise to the sinusoidal system.The pars nervosa supplied with both the superior and inferior hypophysial arteries had a lobular structure;consequently,the intraorganal vascularization had also a lobularcharacter.The cavernous sinuses surrounding the whole hypophysis,with the exception of thedorsal surface of the infundibular stalk,may be divided into five interconnected portionsaccording to their shape,position,and blood drainage.One or two venules on each side of the median eminence formed by the deep andsuperficial capillary networks were drained by the systematic vein.This fact should notbe ignored in considering the venous drainage of the neurohypophysis.