PSYC 2400 Lecture Notes - Lecture 3: Embryonic Stem Cell, Cell Migration, Cell Division
Document Summary
Apoptosis- programmed cell death, is helpful in developing normally. Rapid cell division (also where twins develop) Fertilized egg becomes blastocyst at day 4 (a hollow sphere of cells with bulge of inner cell mass) Characterized by rapid and methodical cell division. Stage when embryonic stem cells are harvested. After implantation, the inner cell mass becomes the embryo and the rest of the cells develop into its support system. Development of major organs and basic anatomy. At end of stage embryo is 1 inch long. Placenta permits the exchange of material between the bloodstream of the fetus and that of the mother. Umbilical cord contains blood vessels that travel between the placenta and developing organism. Formally starts when differentiation of major organs has occurs. Fetus experiences senses, especially sound, taste and tough. By 28 weeks fetus could survive on its on. Full gestation 38-42 weeks <37 considered premature.
