1. Reproductive System
Core 6.6

2. Sexual reproduction – requires union of egg and sperm (fertilization)
Male produces sperm, female produces eggs
Sex cells are made in the gonads (ovaries and testes)
Eggs and sperm are haploid (made by meiosis) so that when they unite, the diploid number is restored

3. Male Reproductive System
Main organ: testes
Located at the base of
the abdominal cavity
Develop from same
embryonic tissue as female
ovaries

4. Urinary bladder
Seminal vesicle
Rectum
Pubic bone
Vas deferens (sperm duct)
Erectile tissue of penis
Ejaculatory duct
Prostate gland
Urethra
Bulbourethral gland (Cowper’s gland)
Glans penis
Epididymis
Testes
Prepuce (foreskin)
Scrotum

5. Testes have 2 functional components:
Seminiferous tubules – produces sperm; only functional at slightly lower body temp.
Scrotal sac approximately 1.5 C cooler that abdomen
Epididymis – coiled tube where sperm travel from seminiferous tubules; lie on top of testes; sperm stored here and acquire ability to swim
Interstitial cells – secrete male sex hormone testosterone

7. Urethra passes through penis and empties to outside
Vas deferens – 2 long ducts that carry sperm from epididymis to urethra (common duct for passage of sperm and urine)
Urethra passes through penis and empties to outside
As sperm passes through the vas deferens, sperm is mixed with seminal fluids to form semen
Seminal fluids are secreted by seminal vesicles, prostate gland, and Cowper’s gland (bulbourethral gland)
Seminal fluid functions as:
Vehicle for transport of sperm
Lubricates passages where sperm pass
Acts as a buffer fluid to protect sperm from acids in female reproductive tract
Contains fructose for source of energy

8. 6.6.4 List three roles of testosterone in males.
Hormonal control of male reproduction:
During embryonic development – small amounts of testosterone cause differentiation of male structures
Testosterone levels remain low until onset of puberty (no sperm production)
At puberty, testes begin to release testosterone which begins production of sperm
After puberty, secondary sex characteristics result from testosterone (beard, pubic hair, underarm hair, deepening of voice, development of larger and stronger muscles)
In adults, it maintains the sex drive (libido)

9. Female Reproductive System
Ovaries – located in abdominal cavity; held in place by ligaments; produce gametes and sex hormones
At time of birth, ovaries already contain hundreds of oocytes (primordial egg cells)
Each oocyte is enclosed in a follicle – each month when egg ripens, follicle grows and fills with fluid and bulges on surface of ovary, ovulation occurs and egg is released into body cavity

10. Follicles in ovary
Ovulation

11. Egg is taken up by oviducts (Fallopian tubes)
Fertilization must occur in upper third of oviduct for baby to result
Egg finishes maturation (completes meiosis II) with penetration of sperm and nuclei fuse

12. Oviducts empty directly into uterus Uterus:
About the size of a fist
Lies in lower portion of abdomen behind bladder
Muscular sac with thick walls of smooth muscle, lined with mucous, contains many blood vessels
Location where fertilized egg implants and develops

13. 6.6.1 Draw and label diagram of the adult male and female reproductive systems.
Oviduct
Ovary
Uterus
Urinary bladder
Rectum
Cervix
Urethra
Vagina
Clitoris
Bartholin’s gland
Labia minora
Labia majora

14. Hormonal control of female reproductive system
6.6.2 Outline the role of hormones in the menstrual cycle, including FSH (follicle stimulating hormone), LH (luteinizing hormones), estrogen and progesterone.
Hormonal control of female reproductive system
At puberty, FSH and LH (made by pituitary gland) stimulate the ovaries to produce estrogen and progesterone. This starts menstrual cycle.
Estrogen stimulates development of secondary sex characteristics (pubic and underarm hair, broadening of pelvis, development of breasts, distribution of fat, changes in voice)
Ovulation & MC

15. 6.6.2 Outline the role of hormones in the menstrual cycle, including FSH (follicle stimulating hormone), LH (luteinizing hormones), estrogen and progesterone.
Human Menstrual Cycle
Averages every 28 days
1st day of menstruation is day one of cycle
Days 1-5: lining is sloughed off (lining is thin)
MSNBC Menstrual Cycle

16. Events during the 1st half of the cycle (approximately days 1-14):
6.6.2 Outline the role of hormones in the menstrual cycle, including FSH (follicle stimulating hormone), LH (luteinizing hormones), estrogen and progesterone.
Events during the 1st half of the cycle (approximately days 1-14):
Pituitary releases FSH stimulating the maturation of several follicles (only 1 will complete maturation); also stimulates ovaries (follicle) to secrete estrogen
Estrogen stimulates thickening of uterine lining
Estrogen stimulates the release of an abrupt surge of LH (by pituitary) almost midway through the cycle; LH surge is followed by ovulation (around the middle of the cycle – about day 14)
Estrogen inhibits the pituitary from releasing more FSH (negative feedback)

17. Events during the 2nd half of the cycle (days 15-28)
6.6.2 Outline the role of hormones in the menstrual cycle, including FSH (follicle stimulating hormone), LH (luteinizing hormones), estrogen and progesterone.
Events during the 2nd half of the cycle (days 15-28)
After ovulation, LH stimulates ruptured follicle to form the corpus luteum; continues to release estrogen and also progesterone
Progesterone promotes continued buildup and support of the uterine lining (also inhibits production of FSH and LH – negative feedback)
If no fertilization occurs , corpus luteum degenerates, progesterone levels drop, lining is shed and cycle starts over

19. 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.
Ovarian and Uterine Cycle

20. Hormonal control of pregnancy
Once fertilized, egg immediately becomes impermeable to other sperm cells – membrane changes consistency
Fertilized egg forms the zygote
Cell division occurs as zygote travels down oviduct to uterus and it implants in the wall of the uterus 8-10 days after fertilization

21. After implantation – fertilized egg forms embryo, umbilical cord (vessels connect baby and mother), and placenta (formed from embryonic and uterine tissues; blood systems of baby and mother come in close contact but never actually mix; exchange occurs between circulatory systems)

22. Fertilized egg produces human chorionic gonadotropin (HCG) which keeps corpus luteum in place, which continues to produce progesterone to sustain pregnancy
Eventually placenta takes over production of estrogen and progesterone to maintain uterine lining

23. 5 weeks
~1 cm long
14 weeks
~6 cm long
20 weeks
~30 cm at end of 24 weeks

25. 6.6.5 Outline the process of in vitro fertilization (IVF).
Normal fertilization takes place in the oviduct
Sometimes a couple may be infertile – unable to conceive a baby
In vitro fertilization involves fertilization of eggs in the laboratory in a test tube
IVF

27. 6.6.6 Discuss the ethical issues associated with IVF.
Pro
Con
Allows infertile couples to have children
Infertility may be passed on to child
Allow individuals that survive cancer treatments to have children using gametes harvested prior to radiation or chemotherapy
Excess embryos are produced to ensure success, those not used must be destroyed
Allows screening for disease and selection of embryo
Often times the mother has multiple pregnancies which can be a risk to the mother’s health, premature birth and put baby at risk (ex. Cerebral palsy)
Individuals that have medical problems that result in the inability to have children would remain childless
Infertility isn’t always caused by health problems but may be that the couple waited too late in life
IVF children are much longed-for and will be more loved and cared for
There are many children in orphanages and foster homes that may benefit by adoption from these caring, childless couples