Here is a normal pancreatic islet of langerhans surrounded by normal exocrine pancreatic acinar tissue 可见一正常胰岛被外分泌腺胰腺的腺泡包绕。
2.
The epithelium is a continuous layer of cells that covers external body surface and forms lining of body cavities and exocrine glands 上皮细胞是人体四大组织细胞之一，覆盖身体表面以及与外界相通的体腔内层细胞层和外分泌腺。
