PSYC 2010U Lecture Notes - Lecture 3: Fetal Alcohol Spectrum Disorder, Heterochrony, Mitosis
Document Summary
Lecture three, the periods of prenatal development and infancy brain, abnormal. Prenatal development: development that occurs between conception and birth, begins in fallopian tube when sperm penetrates ovum and forms a zygote, takes about 266 days for the one-celled zygote to become a fetus of 200 billion cells. Three periods of prenatal period: germinal period (period of the zygote) From conception through implantation: period of the embryo. From 9th week until birth (38 weeks) The mitotic division of the zygote into several cells. Occurs about every 12 hours while the zygote travels down the fallopian tube: zygote travels towards uterus. Transition from germinal to embryonic period: blastocyst differentiates and implants in uterine wall. Period of the embryo: 3 8th week. Implantation of the blastocyst on the uterine wall: embryonic growth - embryoblast becomes: Growth from the top and extending downward. Growth from the centre and extending outward.
