mouse TS23
  embryo
  cavities and their linings
  limb
  mesenchyme
  vertebral axis muscle system
  organ system
  gland
  visceral organ
  alimentary system
  liver and biliary system
  renal/urinary system
  reproductive system
  respiratory system
  cartilage
  larynx
  lung
  respiratory tract
  nervous system
  integumental system
  sensory organ
  cardiovascular system
  skeleton
  tail
  extraembryonic component