Gonzalo-Sanz L M, Insausti R
Acta Anat (Basel). 1976;95(2):309-18. doi: 10.1159/000144622.
The structure of the suprarenal venous system of 25 human suprarenal glands has been studied. From a structural point of view, four portions of the suprarenal vein have been distinguished: the proximal section, the hilus section, the section of the prehilus collaterals, and the distal section. In the hilus section and the section of the prehilus collaterals, the structure of the tunica media is more complex. In the hilus section, spiral fibres are found besides the longitudinal muscle fibres. Three strata of fibres can be observed in the section of the prehilus collaterals at the point where these veins drain into the central vein: two longitudinal strata, external and internal, and a third intermediate stratum corresponding to the looped fibres. The spiral and looped fibres, on contracting, can function as a sphincter. The longitudinal fibres, by means of the traction they exert on the stroma and connective capsule of the suprarenal, increase the intraglandular pressure while decreasing the periglandular pressure. A sympathetic stimulus provokes an increase in the secretion of adrenalin, and, at the same time, a contraction of the muscle fibres of the suprarenal venous system. Under these conditions, the venous return makes use of the emissary veins; and in this way, the secreted adrenalin establishes a close contact with the cortico-suprarenal parenchyma.
对25个肾上腺的肾上腺静脉系统结构进行了研究。从结构角度来看，肾上腺静脉可分为四个部分：近端段、肾门段、肾门前侧支段和远端段。在肾门段和肾门前侧支段，中膜结构更为复杂。在肾门段，除了纵行肌纤维外还发现了螺旋纤维。在肾门前侧支段这些静脉汇入中央静脉处，可以观察到三层纤维：外部和内部两层纵行纤维，以及对应于环形纤维的第三层中间纤维。螺旋纤维和环形纤维收缩时可起到括约肌的作用。纵行纤维通过对肾上腺的基质和结缔组织囊施加牵引力，增加腺内压力，同时降低腺周压力。交感神经刺激会促使肾上腺素分泌增加，同时肾上腺静脉系统的肌纤维收缩。在这种情况下，静脉回流利用导静脉；这样，分泌的肾上腺素就能与肾上腺皮质实质建立紧密联系。
