Sperm Production - Recap starts at puberty made in the seminiferous tubules about 74 days from start to maturity 24/7 production from puberty to death About 50% - 70% viable

Steps in Pregnancy Ovulation Egg is released from the ovary Egg remains viable for 24-36 hours Sometimes ovulation happens first.

Steps in Pregnancy Ejaculation 200-600 million sperm (in semen) ejaculated into the vagina and Sperm are not Capable of fertilizing an egg until 4-6 hours after ejaculation Sometimes ejaculation happens first.

Pregnancy (cont) about 1000 sperm make it to the egg Sperm can remain viable for up to 7 days (3-5 average)

Fertilization One sperm gets into the egg In the fallopian tubes results in a zygote

Pregnancy (cont) The cells in the zygote begin to multiply

Pregnancy (cont) Pregnancy begins after implantation 6-10 days later the zygote implants Pregnancy begins after implantation fertilization + implantation = conception

Implantation fertilized egg attaches to the endometrium in the… Endometrium provides nutrients during early pregnancy Placenta takes over around 7 weeks

Pregnancy (cont) Pregnancy is about 40 weeks long Divided into trimesters, each about 13 weeks Embryo – from 2 weeks to 8 weeks Fetus – From 8 weeks to birth