PSY 111 Lecture Notes - Lecture 2: Umbilical Cord, Fetus, Prenatal Development

• School: Pace University
• Department: Psychology
• Course: PSY 111
• Professor: Sporin

Document Summary

Conception: occurs when egg is fertilized by sperm: egg immediately responds by blocking out all other challengers & pulling in single successful sperm. Germinal stage: lasts from conception to implantation in uterine wall, approximately 10-14 days, zygote: 23 chromosomes from egg & 23 chromosomes from sperm fuse together. Continues to travel down fallopian tube to uterus. Fewer than half of zygotes survive beyond this earliest stage of menstrual cycle. development. If zygote is no longer viable, it will be flushed out in woman"s. If it"s still viable when it completes the journey, zygote will attach itself to wall of the uterus. Soon cells begin to differentiate, each taking on a separate function. Earliest differentiation is between cells on inside of zygote & cells on the outside. Cells on inside will begin to form developing human being. Cells on outside will form protective environment that will provide support for new life throughout pregnancy.