K12 Week 4

Week 4

In week four of embryo development organs begin to form within the embryo and surface features begin to form.

<html5media height="480" width="480">File:Neuraltube_001.mp4</html5media>

This movie of early embryo development from week 3 onward shows the early nervous system forming. Embryo (right) back view with head to top (left) and tail to bottom (right). yolk sac (left, large ball shape) The movie also shows as the embryo grows and folds it increases in size compared to the yolk sac.

Embryo at 4 weeks

(Carnegie stage 13)

• On the embryo surface limb buds can be seen where the future arms and legs will form.

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Cite this page: Hill, M.A. (2023, December 2) Embryology K12 Week 4. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/K12_Week_4

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© Dr Mark Hill 2023, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G