The main structure of the kidney includes: (1) glomerulus: it completes the filtering function of the kidney and removes metabolites and poisons in the body; (2) Renal tubules: reabsorb useful substances (sugar, amino acids, protein and salt, etc.). ) filter out from the glomerulus, secrete some metabolites and drugs to remove them, and adjust the acid-base water balance in the body; (3) Collecting tube and renal pelvis: Urinating tube, which participates in the balance regulation of the body.