Human Reproduction (6.6, 11.4)




read pgs. 270, 271, 276-279 in Tiger book


6.6.1 Draw and label diagrams of the adult male and female reproductive systems. The relative positions of the organs is important. Do not include any histological details, but include the bladder and urethra.
male reproductive system
female reproductive system
male-reproductive-system.png
female-reproductive-system.png
male-reproductive-system2-thumb.jpeg
female_repro..jpg


11.4.1 Annotate a light micrograph of testis tissue to show the location and function of interstitial cells (Leydig cells), germinal epithelium cells,
developing spermatozoa and Sertoli cells.

testis,_100X.jpg
interstitial cells (Leydig cells), germinal epithelium cells, developing spermatozoa and Sertoli cells.

cells of Leydig - secrete testosterone
Sertoli (nurse) cells - nurture developing sperm

11.4.2 Outline the processes involved in spermatogenesis within the testis, including mitosis, cell growth, the two divisions of meiosis and cell differentiation.
spermatogenesis.jpg



11.4.3 State the role of LH, testosterone and FSH in spermatogenesis.

role_hormones_in_spermato.gif


11.4.4 Annotate a diagram of the ovary to show the location and function of germinal epithelium, primary follicles, mature follicle and secondary oocyte.

11.4.5 Outline the processes involved in oogenesis within the ovary, including mitosis, cell growth, the two divisions of meiosis, the unequal division of cytoplasm and the degeneration of polar body.




Oogenesis.jpg


11.4.6 Draw and label a diagram of a mature sperm and egg.
fertilization_of_egg.jpg
sperm_diagram.jpg
1-acrosome, 2-plasma membrane, 3-nucleus, 4-mitochondria, 5-flagellum (tail)


11.4.7 Outline the role of the epididymis, seminal vesicle and prostate gland in the production of semen.


11.4.8 Compare the processes of spermatogenesis and oogenesis, including the number of gametes and the timing of the formation and release of gametes.



6.6.2 Outline the role of hormones in the menstrual cycle, including FSH (follicle stimulating hormone), LH (luteinizing hormone), estrogen and progesterone.

Hormones in the Menstrual Cycle


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.

  • use the graph from your book


6.6.4 List three roles of testosterone in males. Limit this to prenatal development of male genitalia, development of secondary sexual characteristics and maintenance of sex drive.


11.4.9 Describe the process of fertilization, including the acrosome reaction, penetration of the egg membrane by a sperm and the cortical reaction.
  • acrosome, penetration, cortical reaction

During fertilization, a sperm must first fuse with the plasma membrane and then penetrate the femaleegg in order to fertilize it. Fusing to the egg usually causes little problem, whereas penetrating through the egg's hard shell can present more of a problem to the sperm. Therefore sperm cells go through a process known as the acrosome reaction which is the reaction that occurs in the acrosome of the sperm as it approaches the egg. The acrosome is a cap-like structure over the anterior half of the sperm's head.
As the sperm approaches the zona pellucida of the egg, which is necessary for initiating the acrosome reaction, the membrane surrounding the acrosome fuses with the plasma membrane of the oocyte, exposing the contents of the acrosome. The contents include surface antigens and numerous enzymes which are responsible for breaking through the egg's tough coating and allowing fertilization to occur.

The cortical reaction occurs in fertilisation when a sperm cell unites with the egg's plasma membrane, (zona reaction).This reaction leads to a modification of the zona pellucida that blocks polyspermy; enzymes released by cortical granules digest sperm receptor proteins ZP2 and ZP3 so that they can no longer bind sperm, in mammals.
sperm_and_egg_fusion.jpg

11.4.10 Outline the role of HCG in early pregnancy.
Human chorionic gonadotropin interacts with the LHCG receptor and promotes the maintenance of the corpus luteum during the beginning of pregnancy, causing it to secrete the hormone progesterone. Progesterone enriches the uterus with a thick lining of blood vessels and capillaries so that it can sustain the growing fetus. Due to its highly-negative charge, hCG may repel the immune cells of the mother, protecting the fetus during the first trimester.


11.4.11 Outline early embryo development up to the implantation of the blastocyst. Limit this to several mitotic divisions resulting in a hollow ball of cells called the blastocyst.

blastocyst formation

blastocyst_development.jpg


11.4.12 Explain how the structure and functions of the placenta, including its hormonal role in secretion of estrogen and progesterone, maintain pregnancy.
placenta formation

EmbryoPlacenta.gif

11.4.13 State that the fetus is supported and protected by the amniotic sac and amniotic fluid. Embryonic details of the fetus and the structure of amniotic membranes are not required.



11.4.14 State that materials are exchanged between the maternal and fetal blood in the placenta.
11.4.15 Outline the process of birth and its hormonal control, including the changes in progesterone and oxytocin levels and positive feedback.
  • oxytocin secreted to stimulate contractions, contractions positively feed back stimulate oxytocin secretion


6.6.5 Outline the process of in vitro fertilization (IVF).
In vitro fertilization


6.6.6 Discuss the ethical issues associated with IVF.