The functional activity and the lifespan of the corpus luteum depend on adequate pre-ovulatory as well as post-ovulatory gonadotrophic stimulation.
Its lifespan may also be regulated by an LH binding inhibitor. Abstract The ovulatory process can be regarded as a series of biochemical and morphological changes ultimately leading to the release of a mature oocyte and the transformation of the Graafian follicle into the corpus luteum. Oocytogenesis is complete either before or shortly after birth in humans. During the menstrual cycle primary oocytes complete maturation through further meiotic divisions.
Follicle development signals the beginning of the menstrual cycle. At the start of the menstrual cycle, some primary follicles begin to develop under the influence of elevated levels of follicle-stimulating hormone FSH to form secondary follicles.
The primary follicles form from primordial follicles, which develop in the ovary as a fetus during conception and are arrested in the prophase state of the cellular cycle. By around day 9 of the menstrual cycle, only one healthy secondary follicle remain. Which of the following statements about the menstrual cycle is false? As women approach their mids to mids, their ovaries begin to lose their sensitivity to FSH and LH. Menstrual periods become less frequent and finally cease; this is menopause.
There are still eggs and potential follicles on the ovaries, but without the stimulation of FSH and LH, they will not produce a viable egg to be released. The outcome of this is the inability to have children. The side effects of menopause include hot flashes, heavy sweating especially at night , headaches, some hair loss, muscle pain, vaginal dryness, insomnia, depression, weight gain, and mood swings.
Estrogen is involved in calcium metabolism and, without it, blood levels of calcium decrease. To replenish the blood, calcium is lost from bone which may decrease the bone density and lead to osteoporosis. Supplementation of estrogen in the form of hormone replacement therapy HRT can prevent bone loss, but the therapy can have negative side effects.
While HRT is thought to give some protection from colon cancer, osteoporosis, heart disease, macular degeneration, and possibly depression, its negative side effects include increased risk of: stroke or heart attack, blood clots, breast cancer, ovarian cancer, endometrial cancer, gall bladder disease, and possibly dementia. A reproductive endocrinologist is a physician who treats a variety of hormonal disorders related to reproduction and infertility in both men and women.
The disorders include menstrual problems, infertility, pregnancy loss, sexual dysfunction, and menopause. Doctors may use fertility drugs, surgery, or assisted reproductive techniques ART in their therapy.
ART involves the use of procedures to manipulate the egg or sperm to facilitate reproduction, such as in vitro fertilization. Reproductive endocrinologists undergo extensive medical training, first in a four-year residency in obstetrics and gynecology, then in a three-year fellowship in reproductive endocrinology.
To be board certified in this area, the physician must pass written and oral exams in both areas. The male and female reproductive cycles are controlled by hormones released from the hypothalamus and anterior pituitary as well as hormones from reproductive tissues and organs. The hypothalamus monitors the need for the FSH and LH hormones made and released from the anterior pituitary.
FSH and LH affect reproductive structures to cause the formation of sperm and the preparation of eggs for release and possible fertilization. The Leydig cells produce testosterone, which also is responsible for the secondary sexual characteristics of males.
They regulate the female reproductive system which is divided into the ovarian cycle and the menstrual cycle. Menopause occurs when the ovaries lose their sensitivity to FSH and LH and the female reproductive cycles slow to a stop.
Sertoli cell cell in seminiferous tubules that assists developing sperm and makes inhibin. Skip to content Chapter Animal Reproduction and Development. Female germ cells undergo extensive mitotic division in the foetal ovary. In the first stage of oogenesis, the oogonium undergoes oocytogenesis, forming the primary oocyte through mitosis. Like the oogonium, the primary oocyte is a diplod cell, containing two sets of chromosomes and these cells are arrested in the first stage of their meiotic division.
Ovaries contain about 1 million primary oocytes and approximately of these primary oocytes will ultimately be released as mature ova and be available for fertilisation, while the rest will be degenerated. A small number of these primary oocytes will be surrounded by a layer of granulosa cells to form a primary follicle. These follices will not be able to mature appropriately between birth to puberty.
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