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UNSW Embryology

Stage 13/14 Embryo Section D2 (labelled)

Stage 13/14 | D2L | Unlabelled | Tutorial | Previous | Next

Image Features

Respiratory Development and Pharynx

D1: Oesophagus/stomach junction. R lung bud prominent. (L lung bud is more cranial, therefore R primary bronchus is more vertical than the left - cf. Gross Anatomy). note ventral anchoring of pulmonary mesenchyme to the septum transversum, in which is also embedded the sinus venous. Coelomic canals.

Gastrointestinal Development

D2: Ovoid stomach with developing space of the lesser sac on R. Dorsal and ventral attachments of the mesenchyme are now known as dorsal and ventral mesogastria. Coelomic canals.

Neural Development

D2: Spinal cord has enlarged ventral horns (motor neurons).

Musculoskeletal Development

Dl-D3: Dermatome, myotome, sclerotome. Dorsal root ganglia. Notochord. Note the dorsal segmental branches of the dorsal aortae and the inferior cardinal veins. In the walls of the neural tube, note the alar and basal laminae of cells, sulcus limitans.

About Stage 13/14 Embryo

The Carnegie stage 13/14 Pig Embryo is 6mm in size and approximately equal to day 42 Human Embryo. Use the serial images to identify internal features and relationships that exist within the embryo at this stage. Then compare these images with the external appearance of the embryo at this stage and the later internal features of the stage 22 embryo.

Note that the nomenclature "stage 13/14" is not an actual Carnegie stage but indicates that the embryo stage lies between or has features of both stage 13 and stage 14 embryos.

Levels shown on whole embryo are only approximate.

Note that not all embryo features are labelled.

Hint: clicking on each section image above will also step you through the whole embryo in sequence.

UNSW Embryology ISBN: 978 0 7334 2609 4

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