Luteinizing hormone function


Intro to LH. Luteinizing hormones (LH) are one of two hormones comprising the menotropins. Menotropins are produced in the anterior pituitary gland and are absolutely essential for ovulation and conception. The other menotropin is follicle-stimulating hormone (FSH). The two hormones work together for reproduction.

LH increases the amount of estrogen produced by follicle cells in the ovary. The most basic function of LH is to kick start ovulation. The increase in the blood level of LH that triggers ovulation is called the LH surge. The LH surge lasts about 24-48 hours. It is during that time that the egg is released. Once the egg is released a secondary reaction happens, the group of hormone producing follicle cells inside the ovary become the corpus luteum which then produces estrogen and progesterone causing the endometrium to mature in order to support an implanted embryo. If implantation does not occur, the hormone levels drop. Once the tissue has lost its hormonal support, the endometrial lining sloughs off and menstruation occurs. So the LH surge is responsible for dropping the egg and preparing its future home should it be fertilized and need a nice place to grow.

LH levels are low during childhood, too low to get menstruation going. They slowly increase to the point of activating menses. The LH levels continue to rise throughout a woman’s life. It is at menopause that the LH levels get so high they no longer work to trigger menstruation and ovulation stops. LH is key for the lifelong cycle of a woman’s reproductive ability.

Source: Wikipedia, Mayo, WebMD


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