Abstract

HORMONAL REGULATION OF MENSTRUAL CYCLE

*Dr. Shikha Yadav, Prof. Ravindra Singh Yadav and Dr. Annapurna

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Abstract

During their reproductive year, nonpregnant female normally exhibit cyclical changes in the ovaries and uterus. Each cycle takes about a month and involves both oogenesis and prepration of the uterus to receive a fertilized ovum. Hormone secreted by the hypothalamus, anterior pituitary, and ovaries control the main events. Gonadotropinreleasing hormone (GnRH) secreted by the hypothalamus controls the ovarian and uterine cycles. GnRH stimulates the release of folliclestimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary. FSH initiates follicular growth, while LH stimulates further development of the ovarian follicles. In addition, both FSH and LH stimulate the ovarian follicles to secrete estrogens. The menstrual cycle in women is characterized by high variability in cycle length [26- 35days], 5 day menses, a fertile phase from 5 days before to the day of ovulation, and low fertility which is dependent on cycle length and age. Menstruation is the shedding of the lining of the uterus[endometrium] accompanied by bleeding. It occurs in approximately monthly cycles throughout a womans reproductive life, except during pregnancy. Menstruation starts during puberty[at menarche] and stops permanently at menopause.

Keywords: Gonadotropin- releasing hormone (GnRH) secreted by the hypothalamus controls the ovarian and uterine cycles.