1. Tuesday!!!! 3/29
Explain how hormones control the menstrual cycle in human females.
(Total 8 marks)

2. FSH stimulates the development of follicles;
FSH stimulates estrogen secretion (by the developing follicle);
estrogen stimulates the repair of the uterus lining;
estrogen stimulates LH secretion;
LH causes ovulation;
LH causes the development of the corpus luteum;
LH causes secretion of progesterone;
progesterone causes thickening of the uterus lining / prepares uterine lining for implantation;
progesterone / estrogen inhibits secretion of LH / FSH;
falling progesterone levels at the end of the cycle allow FSH production / menstruation;
feedback control;

3. 6.6 Reproduction

4. 6.6.1 Draw and label diagram of the adult male reproductive system.
Testes- in scrotum
Epididymis
Vas deferens- from epididymis
Seminal vesicle- on vas deferens prior to prostate gland
Prostate gland- below bladder where urethra and vas deferens join
Urethra- from bladder through penis
Bladder
Penis- with erectile tissue

6. 6.6.1 Draw and label diagram of the adult female reproductive system.
Ovary w/follicles
Oviduct- showing fimbria
Uterus- showing endometrium (inner lining)
Cervix- between uterus & vagina
Vagina-
Vulva-
Clitoris-
Bladder-
Urethra-

8. 6.6.2 Outline the role of hormones in the menstrual cycle, including
From puberty to menopause
28 days
Ovulation (release egg for possible fert.)
Endometrium becomes highly vascular –support implantation; breaks down if no impl.
Menstrual bleeding (sign of no pregnancy)
FSH (follicle stimulating hormone),
LH (luteinizing hormone),
estrogen, &
progesterone.

9. 6.6.2 Outline the role of hormones in the menstrual cycle, including
FSH (follicle stimulating hormone) & LH (luteinizing hormone)
 prod/secretion of E (follicle cells)
Production of Graafian follicles (follicle cells + oocyte, maturing)
Ovulation (release of oocyte & inner ring of follicle cells)

10. 6.6.2 Outline the role of hormones in the menstrual cycle, including
Estrogen
Bloodstream  endometrium
 vascularization of uterus
If no pregnancy, CL breaks down,  in P and E  vasc breaks down  menstrual bleeding
Progesterone
After ovulation, outer ring foll cells remain in ovary, secrete P
Maintains vascular endometrium (for implantation)
Mitosisfill in “ovul. wound” w/CL, it produces P for ~14d post-ovulation
If no pregnancy, CL breaks down,  in P and E  hypothal  GnRH  FSH/LH

11. - feedback - feedback While E&P high, no more LH&FSH produced,
HYPOTHALAMUS
GnRH
PITUITARY GLAND (ANT.)
- feedback
- feedback LH
FSH
OVARIES
Progesterone (after ovulation)
Estrogen
While E&P high,
no more LH&FSH
produced,
no more foll mature.
ENDOMETRIUM OF UTERUS (INCREASED VASCULAR TISSUE)

13. What about birth control pills???
E & P in pills
High levels maintained
Hypothal doesn’t produce GnRH
Pituitary doesn’t produce FSH, LH
No new Graafian follicles
Ovulation doesn’t occur

15. 6.6.3 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.

18. 6.6.4 List three roles of testosterone in males.
pre-natal development of male genitalia
development of secondary sexual puberty
maintenance of sex drive throughout lifetime

20. Natural Fertilization Process:
In oviduct, h post-ovulation
Several days to travel to uterus (& several mitotic divisions)
Implantation
Problems:
Low sperm count or impotence in male
Ovulation complications
Blockage of oviduct

21. 6.6.5 Outline the process of in vitro fertilization (IVF).
Woman-injections FSH ~10d
Many Graafian follicles develop
Harvest several oocytes (surg.)
Man-sperm donation
Eggs & sperm mixed in separate culture dishes
Microscope  which ova fertilized, normal healthy embryo(s) developing
2-3 introduced to uterus for implantation
$$$$$$$!!!
Use several embryos to decrease failure rate & need to repeat procedure
Healthy, unused embryos frozen, can be used for later implantation if necessary

23. 6.6.6 Discuss the ethical issues associated with IVF.
Against:
Cultured embryos not implanted are frozen or destroyed
Legal issues: uses of frozen embryos if couple divorces
Genetic screening embryos could lead to society choosing desirable characteristics
Repro problems can be passed on genetically (IVF bypasses natural selection, genetic freq of the problem)
Multiple births (& problems) more frequent than w/natural conception
For:
Enables couples (otherwise unable) to have a family
Visibly unhealthy embryos can be eliminated from consideration for implantation
Genetic screening possible prior to implant., can eliminate chance of passing on gen diseases
IVF technology will advance, lead to further benefits in repro biology

24. 6.6.6 Discuss the ethical issues associated with IVF.
TOK:
Potential risks in drug treatments woman is given
Concerns about artificial selection of sperm and injection of them into the egg that occurs with some IVF protocols
Natural selection of sperm with consequent elimination of unhealthy ones is bypassed
Evidence that there are higher rates of abnormality in the offspring as a result