The picture depicts a secondary oocyte becoming a mature ovum after meiosis.
2.
At ovulation the stigma ruptures and the secondary oocyte is released along with follicular fluid.
3.
The secondary oocyte needs to be captured by the fallopian tube where it could be fertilized by a sperm cell.
4.
The sperm binds through the corona radiata, a layer of follicle cells on the outside of the secondary oocyte.
5.
In human embryogenesis, the theca cells form a corpus luteum after a Graafian follicle has expelled its secondary oocyte arrested in second meiosis.
6.
The release of LH matures the egg and weakens the wall of the follicle in the ovary, causing the fully developed follicle to release its secondary oocyte.
7.
Cortical granules inside the secondary oocyte fuse with the plasma membrane of the cell, causing enzymes inside these granules to be expelled by exocytosis to the zona pellucida.
8.
Oogonium ( Oocytogenesis ) > Primary Oocyte ( Meiosis I ) > First Polar Body ( Discarded afterward ) + Secondary oocyte ( Meiosis II ) > Second Polar Body ( Discarded afterward ) + Ovum
9.
The only normal human type of secondary oocyte has the 23rd ( sex ) chromosome as 23, X ( female-determining ), whereas sperm can have 23, X ( female-determining ) or 23, Y ( male-determining ).
10.
The remaining cohort of follicles enter the menstrual cycle, competing with each other until only one follicle is left . This remaining follicle, the late tertiary or pre-ovulatory follicle, ruptures and discharges the oocyte ( that has since grown into a secondary oocyte ), ending folliculogenesis.
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