innermost intercostal muscle


in·ner·most in·ter·cos·tal muscle

(in'ĕr-mōst in'tĕr-kos'tăl mŭs'ĕl) Flat muscle of thorax that occurs as a layer parallel to and is essentially part of internal intercostal muscle but separated from it by intercostal vessels and nerves.
Synonym(s): musculus intercostalis intimus.