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ASSESSMENT STATEMENTS
Draw and label diagrams of the adult male and female reproductive systems.
Outline the role of hormones in the menstrual cycle, including FSH (follicle stimulating hormone), LH (luteinizing hormone), estrogen and progesterone.
Annotate a graph showing hormone levels in the menstrual cycle, illustrating the relationship between changes in hormone levels and ovulation, menstruation and thickening of the endometrium.
List three roles of testosterone in males.
Outline the process of in vitro fertilization (IVF).
Discuss the ethical issues associated with IVF.
Role of Hormones in Menstrual Cycle
• Starting at puberty, females begin a hormonal cycle known as the menstrual cycle
• The purpose is to time the release of a follicle (unfertilized egg) from an ovary to the potential for implantation (egg attaches itself to uterine lining endometrium)
• If no implantation occurs then the endometrium (which is tissue rich with blood vessels) will breakdown and the contents will be released (menstrual bleeding)
Where did my menstrual cycle go?
Hormone: Produced by:
Function:
FSH (follicle stimulating hormone)
Pituitary gland
Stimulates follicle growth (what houses maturing egg); stimulates estrogen secretion; a spike in FSH
levels stimulates ovulation
LH (luteinizing hormone)
Pituitary gland
Spike in LH levels stimulate ovulation; stimulate formation of
corpus luteum (empty follicle after ovulation)
Estrogen Maturing follicle cells
in ovary
Stimulates thickening of the endometrium
Progesterone Corpus luteum
Maintains endometrium; inhibits FSH and LH
Functions of the Male Reproductive Parts:
• Epididymis – after sperm is formed in testes they move to epididymis to be stored where they can mature and gain motility (mature in about 70 days)
• Seminal vesicle – pair of glands near bladder where fructose-rich fluid added ~70% of semen
• Prostate gland – adds additional fluid to semen; this fluid is basic and helps sperm survive in the vagina (which is usually acidic ~4) ~30% of semen
Function of Testosterone in Males:
Testosterone hormone produced in testes
• Determines the development of male genitalia during embryonic development (9-10th week of pregnancy it begins)
• Ensures the development of secondary sex characteristics during puberty (e.g., facial/chest hair, muscles, deeper voices)
• Maintains the sex drive of males throughout their lifetime
• Sperm production (spermatogenesis)
In-Vitro Fertilization (IVF)
• Couples may need in-vitro fertilization if:– Male has a low sperm count (<20 million/mL)– Males with impotence (failure to achieve erection)– Females who cannot ovulate normally (hormonal)– Females with blocked fallopian tubes
Process of IVF1. Woman is injected with FSH for ~10 days (this
insures the development of follicles)2. Several eggs are then harvested surgically3. Man donates sperm into sterile container4. Eggs are mixed with sperm in separate
containers5. Doctors observe via microscope which eggs
are fertilized and if they look healthy6. 1-3 healthy embryos are implanted in woman’s
uterus7. Any unused embryos can be frozen and stored
for future use
Ethical Issues of IVFPROS CONS
Enables unfertile couples to have kids
Embryos not implanted are frozen or destroyed
Unhealthy embryos can be discarded instead of implanted
Complex legal issues related to unused embryos during divorce
Genetic screening can be done on pre-implanted embryos
Genetic screening could lead to “ideal/perfect society” issues
IVF technology will advance knowledge/understanding of
reproductive biology
Reproductive issues passed on to children instead of allowing natural
selection to occur
Multiple births
Where did my menstrual cycle go?
1. Pregnancy
2. Menopause
3. Excess weight loss or gain
4. Eating disorders
5. High stress
6. Increased exercise
7. Medications and birth control
8. Breastfeeding