Why are the liver gallbladder and pancreas considered part of the digestive system but not part of the digestive tract and give one function of each of these three organs?

Answer 1

The food actually passes through an organ of digestion, the food does not pass through the pancreas and gall bladder. They are needed for digestion, they both produce substances which are added to the food as it passes through the digestive system.

Answer 2

They are considered accessory glands of the digestive system because they only send digestive juices and acids to the main digestive organs. Food does not actually enter any of the accessory organs.

Answer 3

The digestive tract refers more to the passages through which food items would travel. (track - think trains; the rails themselves are part of the track, but the motors that change the tracks at a switch don't really have anything to do with the connection of the train to the ground. The motors are there to facilitate the connection, Ya'dig?)

While the pancreas and gall bladder contribute enzymes and other digestive "solvents", the food items should never pass within these organs.

That was sort of poetic...

Answer 4

They are called that because food doesn't directly go through them and they can be removed or lost without harming the digestive process.