PSYC 2450 Lecture Notes - Lecture 4: Embryonic Disc, Semipermeable Membrane, Amnion

• School: University of Guelph
• Department: Psychology
• Course: PSYC 2450
• Professor: Anneke Olthof

Document Summary

Germinal period from conception to implantation and lasts 14 days. Period of the embryo this is where all vital organs are formed and lasts from week 3 to week 8. Period of the fetus this where growth and refinement of the fetus occurs and lasts from week 9 to birth: germinal period. The embryonic disk develops into the embryo. The outer layer transforms into the following: Amnion: is a cushion against blows, helps regulate temperature. Chorion: surrounds the amnion and the lining develops into the placenta. Placenta: is a semi-permeable membrane used for the exchange of oxygen and nutrients between baby and mother; blood cannot pass. Through; the placenta is fully formed by 4 months of age: embryonic period. The formation of vital organs occurs during this period. During week 3, cell differentiation occurs as following . Ectoderm: forms into the nervous system, skin, and hair. Mesoderm: forms into muscle, bones, and circulatory system.