Male Reproductive System
- Seminiferous tubules produce spermatozoa.
- Seminal vesicles produces secretion to aid sperm mobility.
- Prostate gland produces alkaline solution to neutralise acidity of urine.
1 of 8
Female Reproductive System
- Ova are passed to the Fallopian tubes which conveys them to the womb, the muscular walls of the uterus are lined with a mucus called the endometrium, supplies blood during pregnancy.
2 of 8
- Occurs in the germinal epithelium of the seminiferous tubules:
-Diploid spermatogonia divide by mitosis to produce primary spermatocytes.
-These undergo meiosis to form haploid secondary spermatocytes.
-The second meiosis stage forms spermatids which mature into spermatazoa.
- In the wall of the seminiferous tubules are Sertoli cells which secrete a fluid which nourishes the spermatids and protects them from the immune system,
- Interstitial cells produce testosterone.
3 of 8
- The production of the ova:
-Oogonia, formed before birth, undergo mitosis to form primary oocytes.
-The primary oocytes begin meiosis but stop at prophase I.
-The germinal epethelium also divides to form follicle which surround the primary oocyte and form a primary follicle.
-At puberty, hormone stimulate follicles to develop further, one a month matures into a mature Graafian follicle.
-The primary oocyte complete first meiotic divison to form a haploid secondary oocyte and the first polar body.
-The mature Graafian follicle migrates to the surface of the ovary where it bursts and the secondary oocyte is released - ovulation.
-The secondary oocyte starts the second meiotic division but arrests at metaphase unless fertilisation takes place; forming a large ovum and a second polar body.
-Then the ovum and the sperm's nucleus fuse to form a zygote.
-The Graafian follicle forms corpus luteum which releases hormones during pregnancy but breaks down otherwise.
4 of 8
- Internal fertilisation ensures the sperm is deposited into the reproductive tract.
- The sperm is viable for 48 hours, the ovary 24 hours.
- Only one sperm penetrates the clear layer of the ovum called the zona pellucida.
- Sperm can only fertilise once capatation takes place, where the acrosome membrane ruptures and protease enzymes are released which break down the cells around the ovum.
- The tip of the sperm penetrates the weakened part of the membrane.
- The nuclei fuse to form the zygote.
5 of 8
- After fertilisation the zygote divides by mitosis to form the blastocyst which implants itself into the side of the uterus.
- The outer layer of the blastocyst is called the trophocyst and develops the amnion and the chorion, the second has villi which increase surface area for absorption of nutrients.
- It also releases hCG which prevents degeneration of the corpus luteum.
6 of 8
- The difficulty to naturally concieve a child:
-The failure to ovulate which is the abscence or irregular menstrual cycle which can be treated 95% of the time with the drug called clomiphene.
-A blockage of the Fallopian tubes which requires microsurgery.
- In vitro Fertilisation:
-Ovulation is stimulated with hormones, to produce several follicles to form.
-The oocytes are collected.
-The male also produces sperm on the same day.
-The oocyte is placed on the dish and sperm are added to each.
-They are examined to see which have been fertilised.
7 of 8
- Use monoclonal antibodies to test for the presence of hCG, only detecting that 'antigen'.
- Involves detecting the hCG produced by the placenta, and acts as a sign for level of pregnancy.
- The test relies on coloured latex beads and hCG making them fuse to form a noticable colour change.
8 of 8