Pharyngeal arches

Pharyngeal arches: a definition

Pharyngeal arches

Slide 4

Arches, grooves, pouches, and membranes

Pharyngeal cleft
transient “gill-slit”

Slide 7

Phylogeny of early deuterostomes

Pharyngeal arches are unique to vertebrates (subphylum of chordates)

Basic body plan of all chordates (incl. vertebrates)

Evolution of vertebrates involved:

Slide 12

Mesenchyme in cephalic region derived from:

Cephalic mesoderm

Somitomeres

Neural crest migration

Cephalic neural crest migration

Neural crest and mesoderm in H&N area

Neural crest in pharyngeal arches

Slide 20

Neural crest involvement in the development of teeth

Extent of cephalic (cranial) neural crest

Neural crest involvement in the development of the heart

Slide 24

Arch segmentation and rhombomeres

Expression of homeotic genes

Segmental components of arches

Aortic arch development

Aortic arch development cont’d

Branchiomeric nerves: rhombomeric origins

Branchiomeric nerves : pre- and posttrematic rami

Muscles

Skeletal elements

Skeletal derivatives

Slide 35

Slide 36

Slide 37