Human Reproduction

• Testis: produces sperm (by meiosis) and testosterone.
• Epididymis: matures and stores sperm.
• Sperm duct: (Vas deferens) carries sperm from the epididymis to the urethra.
• Urethra: allows passage of either urine or sperm (50-300 mil at one time)
• Scrotum: Keeps testes at a lower temperature of 35* (optimum temp for meiosis)
• Seminal vesicles/Cowper’s gland/Prostate gland: produces seminal fluid which feeds the sperm and allows them to swim.

• Egg:
• Female gamete. Produced by female in the ovary.
• Larger than sperm.

• Sperm:
• Male gamete. Produced by male in the testis.
• Smaller

Characteristics that develop before birth (main sex organs) eg. penis in m, vagina in f.

Characteristics that occur during puberty and differentiate males from females other than sex organs.

The fusion of sperm and egg cell (haploid cells). Results in the formation of a diploid zygote from which a new individual develops.

When the fertilised egg becomes embedded into the lining of the uterus. The zygote now becomes an embryo.

• Infertility is the inability to produce offspring.
• Female infertility is the inability to conceive either by fertilisation failure or implantation failure.
• 1. Egg cell formation or ovulation may not occur due to a hormone imbalance.
• 2. The egg cell may not be able to pass to the uterus due to blockage of Fallopian tubes.

• Male infertility is mostly caused by low sperm production. Causes of this
• 1. Stress
• 2. Alcohol or drug abuse
• 3. High temperature of the testes.
• 4. Low testosterone production.

• (1. Hormones, 2. Ultrasound, 3. Egg renewal, 4. IVF, 5. Transfer to uterus.)
• During IVF fertility drugs are given to the female to stimulate the ovaries to produce more than one egg.
• These eggs are then taken from the females body and into the laboratory.
• In the meantime a sperm sample is taken from male.
• The egg and sperm are mixed together in the hope that fertilisation will occur.
• The sample is placed in the most ideal conditions for fertilisation to occur.
• The main aim of the procedure is to obtain a zygote.
• If successful the zygote develops into a morula, blastocyst and eventually becomes an embryo.
• The developing embryo can now be placed back into the female body for implantation to take place.