Question

What is the role of the Graffian follicle if the ovum is fertilized?

Answer 1

Hint: Fertilisation is the process of fusion of the sperm with a mature ovum. It results in the formation of a single-celled zygote which undergoes cleavage to form an embryo. A zygote is referred to as the vital link between two generations.

Complete answer:
 Let us first look at the structure of Ovary.
The ovary is surrounded by a thin covering of epithelium which encloses the ovarian stroma. It is divide into the outer cortex and an inner medulla. The cortex consists of various follicles at different stages of development.
i) Primary follicle- primary oocyte gets surrounded by a layer of granulosa cells and is called a primary follicle.
ii) Secondary follicle- The primary follicles are surrounded by more layers of granulosa cells and a new theca and form secondary follicles.
iii) Tertiaty or Graffian follicle- The secondary follicles mature and form a fluid-filled cavity called the antrum. At this stage, the primary oocyte completes its first meiotic division and forms the secondary oocyte. This is called the Graffian follicle.

On the 14th day of the menstrual cycle, there is an LH surge from the pituitary which causes the Graffian follicle to burst and release the secondary oocyte, called ovulation. Once the secondary oocyte is released, it is accepted by the fallopian tubes which transfer it to the uterus. Meanwhile, the Graffian follicle degenerates to form the corpus luteum.

If copulation takes place during this phase of the menstrual cycle, the ova and sperm meet at the ampullar-isthmic junction and fertilization takes place. The fertilized egg forms zygote which releases hormones that maintain the corpus luteum. In turn, the corpus luteum releases progesterone hormone which maintains the endometrium of the uterus which is essential to maintain pregnancy. Progesterone is also called the pregnancy hormone.

Note: MENSTRUAL HYGIENE- Maintenance of hygiene and sanitation during menstruation is very important. You must take bath regularly and clean yourself. Use sanitary pads or menstrual cups. Change the pads after 4-6 hrs of usage and dispose of it properly. After handling the napkin wash your hands with soap.