Changes

== Fusion with the Oocyte ==

== Fusion with the Oocyte ==

* When the spermatozoan completely penetrates the zona pellucida and reaches the perivitelline space, it settles into a bed of '''microvilli''' formed by the oocyte plasma membrane.

* When the spermatozoon completely penetrates the zona pellucida and reaches the perivitelline space, it settles into a bed of '''microvilli''' formed by the oocyte plasma membrane.

* Oocyte plasma membrane fuses with the '''equitorial segment''' and the fertilizing spermatozoon is engulfed.  

* Oocyte plasma membrane fuses with the '''equitorial segment''' and the fertilizing spermatozoon is engulfed.  

**Brought about by a fusion protein that is inactive prior to the [[Copulation_-Sperm_in_the_Female_Tract_-_Anatomy_%26_Physiology|acrosome reaction]].

**Brought about by a fusion protein that is inactive prior to the [[Copulation_-Sperm_in_the_Female_Tract_-_Anatomy_%26_Physiology|acrosome reaction]].