nervous system
The organ system that the pancreas belongs to is endocrine
long system
the kidney belongs to the osmo-regulation and the excreatory system.
The brain belongs to the Nervous system. It is the only major organ in that system.nervous system
digestive
Digestive
An organ system is greater than the sum of its parts (organs). So an organ, by itself, can do nothing without the Organ System to which it belongs.
Endocrine system and nervous system .
It belongs to the respiratory system
The digestive system.