K12 Week 5 to 8
Week 5 to 8
In the fifth to eigth (5-8) week of embryo development, organs begin to form within the embryo. This period covers approximately the last stages of major embryonic development growth (Carnegie stages), after this time the embryo is described as a fetus.
Start by comparing at the outside (external) changes in what the embryo looks like from week 5 to week 8 in the pictures below. What new things can you see over this period?
Then have a look at living embryos in the ultrasound movies below. The first 2 movies are at 7 weeks (the first a single embryo, the second twins). The next movie is one week later (week 8) where the limb buds and spine can now be clearly seen. At this early stage ultrasound shows the beating heart is the most obvious feature within the embryo. Ther is also another page covering this period looking at development of the arms and legs.
Cite this page: Hill, M.A. (2021, June 20) Embryology K12 Week 5 to 8. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/K12_Week_5_to_8
- © Dr Mark Hill 2021, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G