How do humans make babies?
Our bodies go to a lot of trouble to make sure we do not run out of people. Making babies is enjoyable but there is a lot of time and effort for the female before and after the birth.
When a female is born she is fully stocked with up to 2 million eggs which is more than enough because you only use about 400 eggs before menstruation (when she stops having monthly bleeding periods)
During the middle of her 28 day long menstrual cycle sometime between the 9th and 21st day and egg becomes ready in one of her two ovaries. It is then drawn into the nearest fallopian tube. (The two fallopian tubes are about 400 mm long and are the pathway to the uterus.)
This release of an egg is called ovulation and signals the start of a race because it can only live for about 24 hours. It needs to meet a male sperm and be fertilised. If these two join together (called conception) they go on to the uterus and start making a new life. If her egg doesn’t meet his sperm then the whole process shuts down – the egg dissolves or absorbed and all of the hormones needed to make the baby stop and the special lining of the uterus is removed which is called a monthly period
On the male side his body is has to make sperm because they are not born with them and have to make fresh ones. The sperm takes up to 10 weeks to make a new batch but as these only last a few weeks he has to make them all the time.
Sperm are made in the testicles, the two glands (roundish balls) in the scrotal sac beneath the penis. The testicles hang outside a man's body because they prefer to be cooler than out body temperature
To produce healthy sperm, testicles have to stay around 94 degrees Fahrenheit – about four degrees cooler than normal body temperature. The sperm are stored in the epididymis (small part of the testicles) before mixing with semen just prior to ejaculation.
Millions of sperm are produced and released with each ejaculation, but only one can fertilize an egg – this is the case even for identical twins. Given their size it is a long way to go to find the female egg and even with a fast start most of them don’t make it. Certainly a cases of the survival of the fittest.
Despite lots of stories on how to choose the sex of your babies the sex of the baby depends on which type of sperm makes it. Those with a Y chromosome make boys and those with an X make a girl. It's very random
And as soon as the hardiest sperm makes it and penetrates the egg, the egg changes instantaneously so that no other sperm can get in. It's like a protective shield that wraps around the egg at the exact moment that first sperm is safely inside.
From the moment of conception when two cells join together the process of growing starts and everything begins to join together to make a fully functioning structure ready to take its first breath of air. However to be absolutely correct what we call pregnancy doesn’t start from the moment the sperm and the egg join together. The genetic material of this embryo is already dividing rapidly and growing but it still has to travel the rest of the way along the Fallopian tube and attaches itself to the wall of the uterus. This trip might take as long as 3-days. Once attached babies are on their way
Sometimes mistakes are made and the embryo doesn’t attach itself to the uterus, but somewhere else, such as the Fallopian tube (Ectopic pregnancy). This can’t work and medication or surgery will be needed.