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18 Cards in this Set
- Front
- Back
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LNMP
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Last Normal Menstrual Period
About 14 days before conception occurs. Widely used in clinical practice. because the onset of the LNMP is usually easy to establish. |
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Path of Spermatogenesis
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Spermatogonium (46, 2N)
Primary Spermatocyte (46, 4N) Secondary Spermatocytes (23, 2N) Spermatids (23, 1N) |
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Path of Oogenesis
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Oogonium (46, 2N)
Primary Oocyte (46, 4N) Secondary Oocyte (23, 2N) Oocyte (23, 1N) |
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How long does the entire process of spermatogenesis take?
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2 Months (including spermiogenesis)
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What is the function of the sertoli cells lining the seminiferous tubules?
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Sertoli cells support and nurture the germ cells, and may be involved in the regulation of spermatogenesis
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How many primary oocytes are present in the ovaries at birth? At adolescence?
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There are about two million primary oocytes in the ovaries of a newborn female. By adolescence, no more than 40 thousand remain.
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The role of GnRH in the female reproductive cycle
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Gonadotropin-releasing hormone, synthesized by neurosecretory cells in the hypothalamus, acts on the anterior lobe of the pituitary gland, stimulating the release of two hormones: Follicle-stimulating hormone and Luteinizing hormone.
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The role of FSH in the female reproductive cycle
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Follicle-stimulating hormone stimulates the development of ovarian follicles and the production of estrogen by its follicular cells.
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The role of LH in the female reproductive cycle
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Luteinizing hormone serves as the "trigger" for ovulation (release of secondary occyte) and stimulates the follicular cells and corpus luteum to produce progesterone.
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What effect does the LH surge have on ovulation?
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The LH surge, elicited by the high estrogen level, appears to cause the stigma to balloon out, forming a vesicle. The stigma soon ruptures, expelling the second oocyte with the follicular fluid.
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What is the zona pellucida composed of?
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The zona pellucida is composed of three glycoproteins (ZPA, ZPB, ZPC), which usually form a network of filaments with multiple pores.
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What does the corpus luteum secrete?
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The corpus luteum secretes progesterone and some estrogen.
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What effect does progesterone have on the endometrium?
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Progesterone, secreted from the corpus luteum, causes the endometrial glands to secrete and prepare the endometrium for implantation of the blastocyst.
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When pregnancy occurs, what prevents the degeneration of the corpus luteum?
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Human chorionic gonadotropin (hCG), secreted by the syncytiotrophoblast of the blastocyst, prevents the degeneration of the corpus luteum.
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For how long is the corpus luteum of pregnancy functionally active?
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Throughout the first 20 weeks, by which the placenta has assumed the production of estrogen and progesterone that is necessary for the maintenance of pregnancy.
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What occurs during capacitation? Where does it occur? How long does it take?
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Freshly ejaculated sperms must undergo capacitation in order to fertilize. During this period, a glycoprotein coat and seminal proteins are removed from the surface of the sperm's acrosome, making the sperm more active. This occurs in the uterus or uterine tubes, and lasts about 7 hours.
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What is the acrosome reaction? When does it occur?
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During the acrosome reaction, a sperm undergoes molecular changes that result in the development of perforations in the acrosome. These changes are associated with the release of enzymes from the acrosome that facilitate fertilization. The acrosome reaction occurs when capacitated sperm come into contact with the corona radiata surrounding a secondary oocyte.
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What is the usual site of fertilization?
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The ampulla of the uterine tube.
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