Layers of ovum
Ovum is the mature female gamete. There are different layers from outside to inside as follows:
1.Corona radiata
2.Zona pellucida
3. Vitelline membrane
Ovum (female gametes) is largest cell in the human body.
It is 130microns in diameter, contain 23 chromosome (23X).
Ovum is surrounded by cell membrane called vitelline membrane (plasma membrane).
During fertilization, egg nucleus is converted into female pronucleus and sperm nucleus converted into male pronucleus.
Human eggs do not have centrioles and human sperm don’t have endoplasmic reticulum.
First polar body formed during formation of secondary oocyte. Can’t go fertilization.
Second polar body occurs after fertilization. Can’t go fertilization.
Zona pellucida
Zona pellucida is penetrated by tiny channels which are important for transport of material from granulosa cells to oocyte.
Corona Radiata (carry message)
Outer envelope is corona radiata (granulosa cells). It derived from cumulus oophorus.
