Studies of a primitive mammalian spleen, the opossum (Didelphis virginiana)

✍ Scribed by Thomas G. Hayes

• Publisher: John Wiley and Sons
• Year: 1968
• Tongue: English
• Weight: 627 KB
• Volume: 124
• Category: Article
• ISSN: 0362-2525
• DOI: 10.1002/jmor.1051240404

✦ Synopsis

Light microscopic sections of the adult opossum (Didelphis virginiana) spleen were observed to lack venous sinuses; this primitive mammalian spleen may be classified as non-sinusal in nature. In the spleen of the opossum, the capillary segments of the penicillar arteries lacked ellipsoid sheaths characteristic of certain mammalian spleens.

Separating the lymphoid nodules from the surrounding red pulp was a distinct band of vascular tissue, the marginal zone. Arising from the central artery within the lymphoid nodule, vessels of capillary dimension were observed to terminate within the marginal zone and the area between lymphoid nodule and marginal zone. In addition to the vascular channels established by the terminal arterial vessels within the red pulp, the system of vessels within the marginal zone has been implicated as a n important intermediate vascular channel within the spleen.