Home Introduction Prefertilization Events First Week (Days 1-7) Second Week (Days 8-14) Embryonic Period (Weeks 3-8) Placenta and Extraembryonic Membranes Musculoskeletal System Nervous System Face and Pharynx Digestive System Urinary System Reproductive System Cardiovascular System Respiratory System Body Cavities Ear Eye Fetal Circulation and Changes at Birth