Term
Outline the role of hormones in the menstrual cycle.
FSH |
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Definition
- released by anterior pituitary
- promotes oogenesis in primary follicle in ovary |
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Term
Outline the role of hormones in the menstrual cycle.
FSH |
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Definition
- released by anterior pituitary
- promotes oogenesis in primary follicle in ovary |
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Term
Outline the role of hormones in the menstrual cycle.
Estrogen |
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Definition
- produced by ovaries
- follice cells: during 1st half of menstrual cycle
- corpus luteum: during 2nd half of menstrual cycle and throughout pregnancy
- promotes secondary sexual characteristics: breast development, pubic hair, fatty deposits developing rounder hips, female behaviour pattern
- inhibits milk production by mammary glands
- increases thickness of endometrium of uterus
- inhibits FSH production in anterior pituitary
- at very high levels, stimulates LH and FSH production in anterior pituitary |
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Term
Outline the role of hormones in the menstrual cycle.
Estrogen |
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Definition
- produced by ovaries
- follice cells: during 1st half of menstrual cycle
- corpus luteum: during 2nd half of menstrual cycle and throughout pregnancy
- promotes secondary sexual characteristics: breast development, pubic hair, fatty deposits developing rounder hips, female behaviour pattern
- inhibits milk production by mammary glands
- increases thickness of endometrium of uterus
- inhibits FSH production in anterior pituitary
- at very high levels, stimulates LH and FSH production in anterior pituitary |
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Term
Outline the role of hormones in the menstrual cycle.
LH |
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Definition
- released by anterior pituitary in response to increasing estrogen levels
- stimulates ovulation:
1. release of secondary oocyte into oviduct
2. follicle remains in ovary and matures into corpus luteum |
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Term
Outline the role of hormones in the menstrual cycle.
LH |
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Definition
- released by anterior pituitary in response to increasing estrogen levels
- stimulates ovulation:
1. release of secondary oocyte into oviduct
2. follicle remains in ovary and matures into corpus luteum |
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Term
Outline the role of hormones in the menstrual cycle.
Progesterone |
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Definition
- produced by corpus luteum:
1. during 2nd half of menstrual cycle
2. throughout pregnancy
- inhibits milk production by mammary glands
- increases/maintains thickness of endometrium of uterus
- inhibits FSH production in anterior pituitary
- inhibits LH production in anterior pituitary |
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Term
Outline the role of hormones in the menstrual cycle.
Progesterone |
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Definition
- produced by corpus luteum:
1. during 2nd half of menstrual cycle
2. throughout pregnancy
- inhibits milk production by mammary glands
- increases/maintains thickness of endometrium of uterus
- inhibits FSH production in anterior pituitary
- inhibits LH production in anterior pituitary |
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Term
| List three roles of testosterone in males. |
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Definition
- pre-natal development of male genitalia
- promotes development of sexual characteristics:
1. primary:
- development of genitalia, ducts, glands
- spermatogenesis
2. secondary:
- larynx growth
- facial, body and pubic hair
- muscle and bone development
- male behaviour pattern
- maintenance of sex drive |
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Term
| Outline: the process of in vitro fertilization (IVF). |
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Definition
1. hormone injections into female cause more than one follicle to mature
2. secondary oocytes harvested from follicles at ovulation, via suction into syringe
3. sperm donated from male mixed with egss in petri dish, or injected directly into egg
4. development to blastocyst stage in petri dish
5. several embryos (up to 4) placed in uterus
6. if implantation is successful, one or more embryos will develop
7. additional embryos frozen for future use |
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Term
Discuss the ethical issues associated with IVF.
Introduction |
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Definition
| Some issues are controversial and around the world the views held by people may vary considerably. Ethical issues involve questioning whether something is wrong or right. Decisions cannot be made using scientific methodsm, but scientists have an obligation to consider ethical issues. |
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Term
Discuss the ethical issues associated with IVF.
Ethical arguments against IVF |
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Definition
- inherited forms of infertility might be passed onto children, which means that the suffering of the parents is repeated in their offspring
- more embryos are often produced than are needed and the spare embryos are sometimes killed, denying them the chance of life
- property of frozen embryos after divorce or death of parents
- problems of long-term storage of embryos
- ethics of competition for sperm from elite males (eugenics)
- embryologists select embryos to transfer to uterus, so humans are deciding whether new individuals survive or die
- IVF is an unnatural process, carried out in laboratories, in contrast to natural conception occurring as a result of an act of love
- post-menopausal pregnancy
- infertility should be accepted as the will of a spiritual power/higher being and it is wrong to try to circumvent it by using IVF to have a child |
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Term
Discuss the ethical issues associated with IVF.
Ethical arguments for IVF |
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Definition
- many forms of infertility are due to environmental factors, so offspring will not inherit them
- any embryos that are killed during IVF are unable to feel pain or suffer, because their nervous system has not developed
- suffering due to genetic disease could be reduced if embryos were screened before being transferred to the uterus
- parents willing to go through the process of IVF must have a strong desire for children and so are likely to be loving parents
- post-menopausal pregnancy
- infertility brings great unhappiness to parents who want to have children, which in some cases can be overcome by IVF |
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