The nervous system in a frog controls the activities of the organs of the body. It also would regulate the internal environment in one's body. All the organs which are also the same parts of nervous system of a vertebrate are present in a frog. The brain,spinal chord,the sympathetic and para sympathetic nerves,cranial nerves,spinal nerves,cranial nuclei and ganglia.
all connective tissue are derived by "mesoderm"{an interaction between ectoderm and endoderm}
