File:Patten049.jpg

Fig. 49. Ventral views of the heart at various stages to show its changes of shape and its regional differentiation

All the drawings were made from dissections with the aid of camera lucida outlines.

The outer of the two layers shown is the epi-myocardium; the inner, the endocardium. In the stages represented in Figs. E-H torsion of the embryo's body is going on at the level of the heart. Since torsion involves the more cephalic regions first and progresses caudad the transverse axis of the body of the embryo is at different inclinations to the yolk at the cephalic end and at the caudal end of the heart. In drawing these figures their orientation was taken from the body at the level of the conus region of the heart, the sinus region therefore appears inclined.

Abbreviations:

• a.v. - constriction between atrium and ventricle
• i.v. - interventricular groove.

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Reference

Patten BM. The Early Embryology of the Chick. (1920) Philadelphia: P. Blakiston's Son and Co.

Cite this page: Hill, M.A. (2024, April 20) Embryology Patten049.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Patten049.jpg

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