BIO210Y5 Chapter Notes - Chapter 18: Zona Pellucida, Amniotic Sac, Fallopian Tube
Document Summary
Fusion of two haploid gametes (23 chromosomes) to produce a zygote (46 chromosomes) dizygotic vs monozygotic. Ca2+ rise enzyme release to ensure fertilization by a single sperm: meiosis ii completion increase in metabolic rate of cells. 200 million spermatozoa enter vagina 10,000 enter uterine tube, 100 reach isthmus. Early development: fertilization, first cleavage starts, two-cell state, first cleavage completes, four-cell stage (blastomeres, early mosula, advanced morula (zona pellucida) Loss of zona pellucida and transport to uterus: blastocyst, endometrium, implantation, trophoblast, amniotic cavity, yolk sac, gastrulation (germ layers: ectoderm, mesoderm, endoderm) Organize the following embryonic stages in the correct temporal order: blastomere, endometrial implantation, gastrula, two-cell stage blastomere 2 gastrula 4 two-cell stage 1 endometrial implantation 3. Formation of the chorion, amnion, and yolk sac. Chorion: important in releasing chorionic gonadotropic releasing hormone. Anterior/posterior, left/right, and superior/inferior axes of developing embryo clearly established. Exchange between maternal blood in lacunae and embryonic blood in chorionic blood vessels.
