Describe the role of hormones in the human menstrual cycle. (20 marks).

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Describe the role of hormones in the human menstrual cycle. (20 marks)
-Just after menstruation, the pituitary gland secretes follicle stimulating hormone, which is carried by blood to the ovary; Follicle stimulating hormone stimulates the development of the Graafian follicles. It also stimulates the follicles within the ovary to secrete oestrogen hormone,
 which is carried by blood throughout the body;
-Oestrogen stimulates the development of secondary female characteristics; and initiates healing and repair of the uterine wall (endometrium) following menstruation; as oestrogen levels rise, a negative- feedback message is sent to the pituitary gland to turn off secretion of follicle stimulating hormone;
-Simultaneously the rise in oestrogen levels stimulates the pituitary gland to secrete luteinising hormone; which is carried by blood; Luteinising hormone levels rise and on reaching peak point causes ovulation (rapture of mature Graafian follicle to release the secondary oocyte or ovum);
-Luteinising hormone also stimulates the reorganization of the remnants of the Graafian follicles to form a functional corpus luteum; it also stimulates the cells of the corpus luteum to secrete oestrogen and progesterone;
-The build up of progesterone (and oestrogen) will stimulate the proliferation (thickening) of the endometrium in readiness for implantation, should fertilization occur; the build up of oestrogen and progesterone levels activate the second negative feedback; by inhibiting the secretion of the FSH and LH by the pituitary glands;
Without gonadotropins (FSH and LH), the corpus luteum begins to deteriorate, slowing oestrogen and progesterone production; the drop in ovarian hormones (oestrogen and progesterone) signals the beginning of menstruation; in this case, the endometrium, denied hormonal support will kink, undergo spasms and is then sloughed off to be released as menstrual fluid (blood and tissue debris); another cycle soon starts

Comments

  1. UnknownApril 12, 2022 at 10:46 PM

    Thank you so much hope I will be able to write on my own

    ReplyDelete

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