Embryonic and postnatal development of endolymphatic sac blood vessels.

The development of perisaccular blood vessels is described during embryology and the postnatal period of the mouse. Primitive sinusoidal vessels already appear at the early otocyst stage as the future endolymphatic sac is formed. Before birth the vasculature attains a more mature appearance with tubular, somewhat fully developed blood vessels. At this stage a primitive basement membrane is also formed. Soon after birth the blood vessels appear mature with developed fenestrations and micropores, giving them an appearance comparable to blood vessels in other fluid transporting organs.