<P> The face and neck development of the human embryo refers to the development of the structures from the third to eighth week that give rise to the future head and neck . They consist of three layers , the ectoderm , mesoderm and endoderm , which from the mesenchyme ( derived form the lateral plate mesoderm and paraxial mesoderm ) , neural crest and neural placodes ( from the ectoderm ) . The paraxial mesoderm forms structures named somites and somitomeres that contribute to the development of the floor of the brain and voluntary muscles of the craniofacial region . The lateral plate mesoderm consists of the laryngeal cartilages ( arytenoid and cricoid ) . The three tissue layers give rise to the pharyngeal apparatus. , formed by 6 pairs of branchia / pharyngeal arches , a set of pharyngeal pouches and pharyngeal grooves , which are the most typical feature in development of the head and neck . The formation of each region of the face and neck is due to the migration of the neural crest cells which come from the ectoderm . This cells determine the future structure to develop in each pharyngeal arch . Eventually , they also form the neurectoderm , which forms the forebrain , midbrain and hindbrain , cartilage , bone , dentin , tendon , dermis , pia mater and arachnoid mater , sensory neurons , and glandular stroma . </P>
<P> The face and neck development of the human embryo refers to the development of the structures from the third to eighth week that give rise to the future head and neck . They consist of three layers , the ectoderm , mesoderm and endoderm , which from the mesenchyme ( derived form the lateral plate mesoderm and paraxial mesoderm ) , neural crest and neural placodes ( from the ectoderm ) . The paraxial mesoderm forms structures named somites and somitomeres that contribute to the development of the floor of the brain and voluntary muscles of the craniofacial region . The lateral plate mesoderm consists of the laryngeal cartilages ( arytenoid and cricoid ) . The three tissue layers give rise to the pharyngeal apparatus. , formed by 6 pairs of branchia / pharyngeal arches , a set of pharyngeal pouches and pharyngeal grooves , which are the most typical feature in development of the head and neck . The formation of each region of the face and neck is due to the migration of the neural crest cells which come from the ectoderm . This cells determine the future structure to develop in each pharyngeal arch . Eventually , they also form the neurectoderm , which forms the forebrain , midbrain and hindbrain , cartilage , bone , dentin , tendon , dermis , pia mater and arachnoid mater , sensory neurons , and glandular stroma . </P>
when does development of the human face occur
when does development of the human face occur
from the third to eighth week
from the third to eighth week