Cell: smallest unit of structure and function of body tissue: group of cell and extracellular ground substance four basic tissue --epithelium ↓- connective tissue ---muscular tissue nervous tissue organ: made up of tissue, have special shape structure and function shen: organs which have related function get togetherCell: smallest unit of structure and function of body ↓ tissue: group of cell and extracellular ground substance four basic tissue: ---epithelium ↓ ---connective tissue ---muscular tissue ---nervous tissue organ: made up of tissue, have special shape, structure and function ↓ system: organs which have related function get together