- The middle germ layer of the embryo.
Definition from: MeSH via Unified Medical Language System at the National Library of Medicine
- Middle layer of the three primary germ layers of the mammalian embryo; from it are derived the connective tissue, bone and cartilage, muscle, blood and blood vessels, lymphatics and lymphoid organs, notochord, pleura, pericardium, peritoneum, kidney and gonads.
Definition from: CRISP Thesaurus via Unified Medical Language System at the National Library of Medicine
See also Understanding Medical Terminology.