10 Cool facts to know about Sex/reproduction, page 1

As taboo as it may be in some places, sex is an important part of human life as a facet of
relationships and the means to reproduce. Here are a few things you might not have known.

1. On any given day, sexual intercourse takes place 120 million times on earth. Humans are a quickly proliferating species, and with about 4% of the world’s population having sex on any given day, it’s no wonder that birth rates continue to increase in many places all over the world.

2. The largest cell in the human body is the female egg and the smallest is the male sperm. While you can’t see skin cells or muscle cells, the ovum is typically large enough to be seen with the naked eye with a diameter of about a millimeter. The sperm cell, on the other hand, is tiny, consisting of little more than nucleus.

3. The three things pregnant women dream most of during their first trimester are frogs, worms and potted plants. Pregnancy hormones can cause mood swings, cravings and many other unexpected changes. Oddly enough, hormones can often affect the types of dreams women have and their vividness. The most common are these three types, but many women also dream of water, giving birth or even have violent or sexually charged dreams.

4. Your teeth start growing 6 months before you are born. While few babies are born with teeth in place, the teeth that will eventually push through the gums of young children are formed long before the child even leaves the womb. At 9 to 12 weeks the fetus starts to form the teeth buds that will turn into baby teeth.

5. Babies are always born with blue eyes. The color of your eyes depends on the genes you get from your parents, but at birth most babies appear to have blue eyes. The reason behind this is the pigment melanin. The melanin in a newborn’s eyes often needs time after birth to be fully deposited or to be darkened by exposure to ultraviolet light, later
revealing the baby’s true eye color.

6. Babies are, pound for pound, stronger than an ox. While a baby certainly couldn’t pull a covered wagon at its present size, if the child were the size of an oxen it just might very well be able to. Babies have specially strong and powerful legs for such tiny creatures, so watch out for those kicks.

7. One out of every 2,000 newborn infants has a tooth when they are born. Nursing mothers may cringe at this fact. Sometimes the tooth is a regular baby tooth that has already erupted and sometimes it is an extra tooth that will fall out before the other set of choppers comes in.

8. A fetus acquires fingerprints at the age of three months. When only a small fraction of the way through its development, a fetus will have already developed one of the most unique human traits: fingerprints. At only 613 weeks of development, the whorls of what will be fingerprints have already developed. Oddly enough, those fingerprints will not
change throughout the person’s life and will be one of the last things to disappear after death.

9. Every human spent about half an hour as a single cell. All life has to begin somewhere, and even the largest humans spent a short part of their lives as a single celled organism when sperm and egg cells first combine. Shortly afterward, the cells begin rapidly dividing and begin forming the components of a tiny embryo.

10. Most men have erections every hour to hour and a half during sleep. Most people’s bodies and minds are much more active when they’re sleeping than they think. The combination of blood circulation and testosterone production can cause erections during sleep and they’re often a normal and necessary part of REM sleep.

More to follow ........

Credit to Christina Laun (For research into this)

[edit on 1-11-2008 by Spartannic]