What are the changes in the oogonia during the transition of a primary follicle to Graafian follicle ?
The cells of germinal epithelium divides rapidly and forms many diploid oogonia. Oogonia grows and forms primary oocytes.
Each primary oocytes then gets surrounded by a layer of granulosa cells and then called primary follicle.
The primary follicle gets surrounded by more layer granulosa cell and a new theca called secondary follicle. The secondary follicle soon transforms into a tertiary follicle which is characterised by a fluid filled cavity called antrum.
The primary oocyte within the tertiary follicle grows in size and that completes its first meiotic division. It is an unequal division resulting in the formation of large haploid secondary oocyte and a tiny first polar body. The tertiary follicle further changes into mature follicle or graafian follicle which breaks and releases secondary oocyte from the ovary. This is called ovulation.
Corpus luteum is developed from
A temporaryendocrine gland in the human body is
No new follicles develop in the luteal phase of the menstrual cycle because
Match the items given in the Column $I$ with those in Column $II$ and select the correct option given below:
Column $I$ |
Column $II$ |
$(a)$ Proliferative Phase |
$(i)$ Breakdown of endometrical lining |
$(b)$Secretory Phase |
$(ii)$ Follicular phase |
$(c)$ Menstruation |
$(iii)$ Luteal Phase |
Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Endometrium is necessary for implantation of blastocyst.
Reason $R$: In the absence of fertilization, the corpus luteum degenerates that causes disintegration of endometrium.
In the light of the above statements, choose the correct answer from the options given below: