Question

1. Describe the formation, function, and fate of the corpus luteum. Also, describe the changes that occur in the endometrium during the luteal phase.

Answer 1

The corpus luteal hormones makes the uterus suitable for implantation of   ovum after fertilization.

It helps in nourishment of the embryo.

If the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs

.In process of ovulation, an egg is released from a dominant follicle and fertilization occurs and then the follicle seals itself off and forms what is known as a corpus luteum.

Luteum forms after proliferation of granulosa cells and differentiation of cells into progesterone producing cells .

This process is known as lutenization in which granulosa and theca cells change to luteal cells .

This process occurs by lutenizing hormones

Corpus luteum is a glandular yellow body .

In non pregnancy corpus luteum is a follicle remnant after ovulation.

1. It helps in secretion of hormone
2. Acts as temporary endocrine gland
3. secretes large quantities of progesterone and small quantity of estrogen
4. Facilitate ovulation
5. Facilitates fertilization
6. Facilitate passage of ova into oviducts .
7. Maintainance of pregnancy, for three months and abortion occurs on removal of corpus luteum.

Changes that occur in the endometrium during the luteal phase.

Luteal phase lasts 14 days - then there is a regression of corpus luteum-decrease in oestrogen and progesterone.

This leads to spasmodic contraction of spiral section of endometrial arterioles

Ischaemic necrosis occurs

Shedding of superficial layer

Bleeding occurs

The spasms are associated with Prostaglandins which causes increased uterine contractions during menstrual flow