Ключевые слова: absorption, anatomical, anatomy, biology, biopsy, bowel, cancer, cell, cilia, colon, columnar, columnar epithelium, digestion, digestive, disease, duodenum, educational, epithelial, epithelial cells, epithelium, gastrointestinal, gut, health, histological, histology, human, human tissues, intestinal, intestine, lining, medicine, microbiology, microscopic, microvilli, mucosa, nucleus, nutrients, pathology, science, simple columnar epithelium, small, squamous, stomach, structure, surface, system, tissue, tract, villi, villus,