COLECUL E
III. Germ Layers - differentiated tissue layers in the embryos of all animals except
which have no tissues.
A. endoderm -
germ layer: give rise to lining of digestive tract;
respiratory system; urinary bladder; digestive organs; liver; many glands
B. mesoderm-
germ layer: give rise to most of the skeleton;
muscles; circulartory system; reproductive organs; excretory organs
germ layer: give rise to outer layer of skin;
C. ectoderm -
nervous system; and sense organs.