Embryology of the head and neck

Abstract Development of the head is dominated by the changing shape of the brain and the formation of pharyngeal arches through which blood from the ventrally placed heart can pass to the dorsal aorta. The origin of the cell population within the head and neck is important as it predicts the behaviour and attributes of the cells and their progeny. The neural crest gives rise to an extensive mesenchymal population which contributes to the skull and enters and patterns the pharyngeal arches. The skull (neurocranium) forms around the developing brain and its emerging nerves. The base of the skull forms initially in cartilage (endochondral ossification) and the vault forms from neural crest mesenchyme (intramembranous ossification). The face and jaws (viscerocranium) form around the developing pharynx from a series of pharyngeal arches (numbered 1,2,3,4 and 6) which pass from the lateral sides of the pharynx to meet ventromedially.