The Illinois state sales tax rate is 6.25%, and the average IL sales tax after local surtaxes is 8.19%. Counties and cities can charge an additional local sales tax of up to 3.5%, for a maximum possible combined sales tax of 9.75%.
(clue: look up Hirschsprung's disease.) The first important step in development of the digestive system occurs during folding of the embryonic disc as neurulation takes place (weeks 4 and 5) - the thin endodermal layer is gathered up' inside the embryonic body to form a tubular structure. Gut tube, respiratory diverticulum, yolk sac, and allantois.
The embryo is in three layers at this point. Itâs only the size of the tip of a pen. 1  The top layer is the ectoderm. This is what will eventually turn into your babyâs skin, nervous system, eyes, inner ears, and connective tissue.  The middle layer is the mesoderm.