Development of organs – general embriology

Development of organs – general embriology
Elongation of the blastocyst
Lamina neuralis (with blue) and
the sulcus neuralis.
On both sides of sulcus neuralis
somites start to develop.
Primitive streak and primitive node
(stria primitiva, nodus primitivus)
1
Types of placenta
ca: zonaria, endotheliochorial
eq: diffuse, epitheliochorial
su: diffuse, epitheliochorial
ru: cotyledonaria (multiplex),
synepitheliochorial
ho: discoidea, hemochorial
Fetal cotyledon + maternal caruncula = placentome
2
3
Early differentiation of mesoderm
and closure of neural folds
Bending of the embryo and formation of somites
Single mesoderm and chorda dorsalis
Paraxial mesoderm and lateral plate mesoderm
Separation of lateral plate mesoderm
Intermedier mesoderm (in the middle),
somatopleura (next to ectoderm),
and splanchnopleura (next to entoderm).
Differentiation of entoderm,
early entodermal structures
4
Latero-lateral folding of the embryo
Colors:
- blue: ectoderm
- red: mesoderm
- yellow: entoderm
Cranio-caudal folding of the embryo
Videos about folding:
- https://www.youtube.com/watch?v=qMnpxP6EeIY
- http://www.indiana.edu/~anat550/genanim/latfold/latfold.swf
5
Development of body cavities
Common thoracic and abdominal cavity
canalis
pleuroperitonealis
The entodermal-derived
lungs gradually grow into
the thoracic cavity
Adhesion of plica pleuropericardiales
/n. phrenicus (with black) and v. cardinalis
communis (with pink) are embedded into to fold/
Formation of diaphragm: septum transversum (ventrally, orange), pleuroperitoneal folds (from both sides, blue),
mesenterium dorsale (in the midline), and mesodermal-derived muscle-cell ingrowth (circularly,6 red)