Explain the development of a secondary oocyte ( ovum) in a human female from the embryonic stage upto its ovulation. Name the hormones involved in this process.

Explanation

It starts during embryonic growth with millions of gamete mother cells forming in the fetal ovary .These cells undergo meiosis but get termporarily arrested at the prophes and are called primary oocytes.Before-reaching puberty, a large number of primary oocytes degenerate and the remaining ones get surrounded by layers of granules cells and new theca and are called secondary follicles . The secondary follicles are then converted into tertiary follicle that have a fluid-filled cavity called the antrum. At this st age, the primary oocyte present within tertiary follicle completes meiosis, which result in the formation of haploid secondary ooycte and tiny polar body. Tertiary· follicle further changes into graafian follicle. The secondary oocyte is surrounded by the zone pellucida: Then graafian follicle ruptures to release the ovum by ovulation.
The hormones involved inthe above process are :
( i) GnRH (Gonadtropin releasing Hormove , from Hypothalamus )
(ii) LH and FSH ( From anterior pituitary )
(iii) Estrogen and progesterone ( from ovary ) .