Layer of connective tissue, underlying the epithelium of a mucus membrane, containing capillaries and lymphatic vessels, as well as fibroblasts and cells of the immune system.
Source:
PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 772 (https://doi.org/10.1515/pac-2015-1202)