Contraception and Birth
Each month a woman will produce one egg from both of her ovaries, which will eventually then lie on eat side of her uterus. The egg will firstly need to travel down the fallopian tubes and then it will be released into the uterus. Male semen will then be needed for conception, this contain millions of sperm which only one will be needed to make the father genetic contribution to a baby. Sperm contains 23 chromosomes the same as an egg, sperm also swims as it has to move up the cervix, in the uterus and along the fallopian tubes. During sexual intercourse the man will ejaculate and the sperm and the egg will form a ball of cells called an embryo. After one to one and half days later the egg will begin to divide. Then after 3 weeks of fertilisation the embryo will grow to be up to 0.5cm long and will start to develop a brain, eyes, ears and limbs. At 8 weeks organs are formed, a heartbeat will become recognisable and so will facial features. The embryo will now be 3-4 cm long and is now called a foetus. At 20 weeks growth and development is still continuing and the foetus is now half the length and weight of a new born baby. At 40 weeks the foetus is ready to be born at around 50 cm long and weighing 3.5 kg. At 9 months a fully formed baby is born.
Infancy 0-3 years
Physical Development-
At birth babies are able to react to sudden noises, close their eyes to bright lights and open their eyes when being held up right. A baby is born with little head and neck movements; the first important physical skill they need to master is lifting their head and shoulders. At 4 months he or she will become stronger and be able to lift their chest. At 6 to 7 months he or she will be able to play with objects using their hands, which is a beginning of gross motor skills. Through a babies development muscles begin to strengthen dramatically,