K12 Limbs

From Embryology

Limbs - Arms and Legs

The arms and legs (we call them "limbs") begin as small buds on the sides of the embryo body.

Stage20-23 limbs a.jpg

Human Limb Development during week 8

From week 5 to week 8 of development, changes occur in the shape and structure of the embryo limbs.

The arms begin to develop before the legs. If you look at the whole embryo the legs always look younger (less developed) than the arms (almost a stage behind, about 2 days difference).

Look above at the pictures and see what changes you can see in the shape, features and position of the arm and leg.

Towards the end of this time (9 weeks) the embryo will also begin to move the arms and legs.


K12 Links: Start Here | Week 1 | Week 2 | Week 3 | Week 4 | Week 5 to 8 | Arms and Legs | Heart | Fetus | Brain Growth | Eyes and Ears | Animal Development Times | Humans and Animal Embryology | Comparative Embryology | Thalidomide

Words Used

digit - word used to describe either the finger or toe.

limb - word used to describe either the arm or leg.

limb bud - the first time you can see on the embryo surface where the arm or leg will form. It looks like a "bud" or "paddle" without any features.


Cite this page: Hill, M.A. (2024, March 29) Embryology K12 Limbs. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/K12_Limbs

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G