RESUMEN
A study was made on 18 embryos of developmental stages 13-15 (5(th) week). Serial sections made in horizontal, frontal, and sagittal planes were stained with routine histological methods and some of them were treated with silver. In embryos of stage 13, the otic vesicle is at the rhombomere 5, and close to the vesicle is the facial-vestibulocochlear ganglionic complex in which the geniculate, vestibular, and cochlear ganglion may be discerned. These ganglia are well demarcated in embryos of stage 14. In the last investigated stage (15(th)) the nerve fibres of the ganglia reach the common afferent tract.
Asunto(s)
Nervio Facial/embriología , Ganglio Geniculado/embriología , Ganglio Espiral de la Cóclea/embriología , Nervio Vestibular/embriología , Nervio Vestibulococlear/embriología , Diferenciación Celular/fisiología , Colorantes , Nervio Facial/citología , Ganglio Geniculado/citología , Humanos , Neurogénesis/fisiología , Organogénesis/fisiología , Rombencéfalo/citología , Rombencéfalo/embriología , Células Receptoras Sensoriales/citología , Ganglio Espiral de la Cóclea/citología , Coloración y Etiquetado , Nervio Vestibular/citología , Nervio Vestibulococlear/citologíaRESUMEN
The cochlear ganglion was investigated in serially sectioned human embryos at developmental stages 18 and 19 (44-46 postovulatory days). During this period the cochlear ganglion is separated from the vestibular ganglion, and it is adjacent to the cochlear duct. In embryos of investigated stages fibers of the cochlear ganglion enter the nuclei in the brain.
Asunto(s)
Ganglio Espiral de la Cóclea/embriología , Desarrollo Embrionario y Fetal/fisiología , Femenino , Humanos , Embarazo , Primer Trimestre del EmbarazoRESUMEN
Studies of serial sections and reconstructions of embryos at stage 13 (32) postovulatory days) revealed that the cranial neural tube in the investigated embryos possesses 15 neuromers: 1 telencephalic, 3 diencephalic, 3 mesencephalic, and 8 rhombencephalic. Within the primary efferent column all nuclei of the cranial nerves may be distinguished. Also fibers entering brain from cranial nerve ganglia form the common afferent tract. The relation of neuromers to the motor nuclei of the cranial nerves is following: M1-oculomotor, M2-trochlear, Rh2-trigeminal, Rh4-facial, Rh6-glossopharyngeal, Rh7-vagal, Rh8-hypoglossal.
Asunto(s)
Encéfalo/embriología , Embrión de Mamíferos/anatomía & histología , Encéfalo/anatomía & histología , Nervios Craneales/embriología , Diencéfalo/embriología , Vías Eferentes/embriología , Edad Gestacional , Humanos , Mesencéfalo/embriología , Rombencéfalo/embriología , Telencéfalo/embriologíaRESUMEN
In embryos at stage 13th vestibulocochlear ganglion forms a complex structure with the geniculate ganglion. The geniculate ganglion is placed rostrally and may be distinguished from the vestibulocochlear ganglion. Also at this stage there is a sign of differentiation of the vestibular and cochlear ganglia.