Interactive CS18 Embryo Model


The model is high resolution. Please allow time for it to load.

        Key to anatomical regions

  • Neural tube
  • Eye
  • Ear
  • Dorsal root ganglia
  • Heart
  • Liver

Movies of CS18 embryos


The movies below show volume renders of OPT models. No staining has been used on any of the specimens and the images were captured using autofluorescence with a FITC filter.


N318 46XY
N343 46XX
N417 46XX


N451 46XY
N563 46XY
N757 46XX




Painted Anatomical Regions


The movies below show anatomical domains defined in the N318 model. The domains have been manually defined in the OPT model using specialised software and then visualised using commercial rendering packages.

The various domains are: neural tube - orange; heart - red; liver - dark green; optic vesicle - dark blue; otic vesicle - yellow; dorsal root ganglia - cyan.


N318 46XY



Carnegie Stage 18 Definition



a 3D model of a human embryo


Age is approximately 44 postovulatory days

Length is approximately 13-17 mm

External Features Include: the body is more of a unified cuboidal mass, both cervical and lumbar flexures are indicated; the digital plate of the hand is definitely notched, the elbow region is usually discernable, toe rays can be identified in some specimens; eyelid folds are present in the more advanced specimens; a distinct tip of the nose can be seen in profile.

O'Rahilly R and Muller F [1987] Developmental Stages in Human Embryos. Carnegie Institute, Washington, Publication no. 637