Articles written in Proceedings – Animal Sciences
Volume 97 Issue 6 November 1988 pp 479-489
The pituitary glands of
Volume 98 Issue 3 May 1989 pp 149-166
Volume 99 Issue 4 July 1990 pp 289-303
Vascularisation of the placenta of several species of bats representing 8 families is reported. Maternal vascularisation in all these bats is effected by a few large vessels which pass through the entire thickness of the placenta and give rise to numerous radial branches on reaching the foetal surface of the placenta. Maternal blood is returned through placental tubules which empty into large venous channels at the utero-placental junction. Foetal vascularisation is brought about by two allantoic arteries which capillarise over the placental tubules, and a large allantoic vein. In the exchange areas there is mostly crosscurrent circulation of the maternal and foetal bloods. Only in emballonurid bats is there an haematoma from which maternal blood is not drained back but is absorbed by cells of the trophoblast of chorionic villi.