anatomy

facial development

early mouth, becomes oral and nasal cavity, lined with ectoderm

oropharyngeal membrane (buccopharyngeal membrane)

area of ectoderm and endoderm together, no mesoderm in between, ruptures by end of week 4

Rathke’s pouch

develops into anterior pituitary gland

frontal process

medial nasal process and lateral nasal process

1st Branchial Arch

mandibular process and maxillary process, and trigeminal nerve

medial nasal process

center and tip of nose, nasal septum, globular process, philtrum and middle of upper lip, anterior palate (premaxillary segment)

lateral nasal process

sides of nose (ala) and infraorbital areas

globular process

becomes the philtrum

second branchial arch (hyoid arch)

• facial nerve, muscles of facial expression

• part of hyoid bone and middle ear bones

  • posterior tongue

third branchial arch

• glossopharyngeal nerve

• part of hyoid bone

  • posterior tongue

fourth to six branchial arch

formation of larynx and pharynx, and glossopharyngeal and vagus nerve

placodes developlment

thickened area of ectoderm for special sense organs