8.1 The Carnegie stages

Synoptic table of the Carnegie stages 14 - 16

Stage 14

Approx. 33th day

5 - 7 mm

1 2 3 4 5 6 7 8 9 Telencephalon Mesencephalon Myelencephalon Ocular primordium Fourth ventricle Cervical sinus Mesonephric cord Bud of the upper extremity Bud of the lower extremity

Characteristic signs:Opthalmic vesicle Genesis of the endolymphatic canal Augmented cephalo-cervical flexure Cerebellar primordium Visible ocular primordium Sixth pharyngeal arch

Stage 15

Approx. 36th day

7 - 9 mm

1 2 3 4 5 6 Umbilical cord Cardiac prominence Nasal placode Ocular primordium Bud of the upper extremity Bud of the lower extremity

Characteristic signs:Lens vesicle covered with the ectoderm Auditory primordium Genesis of the hand plate

Stage 16

Approx. 39th day

8 - 11 mm

1 2 3 4 5 6 7 8 9 10 Umbilical cord Nasal pit Nasolacrimal groove Ocular primordium Flexura pontina Flexura cervicalis Auditory primordium Cardiac prominence Hand plate Foot plate Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon Spinal cord

Characteristic signs:Deep, ventrally lying nasal pit Pigmentation of the eye Genesis of the foot plate Physiologic umbilical hernia Nasolacrimal groove

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