The male and female reproductive systems

1. Sperm: made in a testis → stored and matured in the epididymis → along the sperm duct → fluids added from the seminal vesicles and prostate gland → along the urethra → out through the penis. In the female, sperm swim from the vagina through the cervix and uterus into the oviducts.
2. Egg: released from an ovary → swept up by the funnel → moved along the oviduct by cilia and muscle → reaches the uterus. If it meets sperm, it is fertilised in the oviduct (Lesson 4).
3. Where they meet: the oviduct, so this is where fertilisation happens.

Core body temperature is about 37 °C, and the scrotum keeps the testes typically 2 to 3 °C cooler.

1. Temperature in the scrotum: about $37-3=34{}^{\circ }\text{C}37\; -\; 3\; =\; 34\backslash \; ^\backslash circ\backslash text\{C\}$ to $37-2=35{}^{\circ }\text{C}37\; -\; 2\; =\; 35\backslash \; ^\backslash circ\backslash text\{C\}$.
2. Explain: the enzymes involved in making sperm work best at this slightly lower temperature, so sperm production needs the testes to hang outside the body.
3. Apply: in a boy whose testes have not descended into the scrotum, sperm production may be affected, which is one reason doctors check this in babies and young children, and treat it early.