PSYCH 250 Lecture Notes - Lecture 3: Birth Weight, Neural Tube, Miscarriage
Document Summary
Ovulation: the moment during a woman"s monthly cycle when the ovum (egg) is expelled from the ovary. Ovum survives 24-48 hours in fallopian tube. Sperm cells survive 2-5 or 6 days. Fertilization: union of sperm and ovum, conception. Almost all human cells contain 46 chromosomes. Fertilized egg contains a unique set of 46 (23 from each parent) Germinal period (0 to 2 weeks): lasts from fertilization to full implantation (when the cell mass attaches to the uterus wall) Takes 3 days to go down fallopian tube to the uterus. When it reaches the uterus, it becomes a blastocyst. Cell mass moves down uterus and implants in wall. Blastocyst becomes imbedded into the uterus wall. Only 20-33% of fertilized eggs complete the journey from the fallopian tube to the uterus and implant in the uterine wall. Outer layer of cells, will develop into-life support systems. Amnion: protective sac, encases organism in amniotic fluid, a cushion and temperature regulator.
