Assertion: epithelium | /r/CapableOf | form digestive tract
Facets:
Source sentences:
text: They form the digestive tract, the external skin, secretory glands, the inner lining of the mouth, the lining of hollow parts of every organ-like as lungs, heart, eyes, ear, urogenital tract, and also a ventricular system of the brain and central canals of the spinal cord.