There are single-layered columnar epithelium in the stomach and intestine.The digestive glands are composed of liver and pancreas and t...

• 消化腺包括肝脏和胰腺,肝小叶分界明显,胰腺外分泌部由腺泡组成,内分泌部即胰岛分散存在于外分泌部之间。