Schlundbogen

Pattern of

the branchial arches. I-IV branchial arches, 1-4 Pharyngeal pouches (inside) and/or pharyngeal grooves (outside), a Tuberculum laterale, b Tuberculum impar, c Foramen cecum, d Ductus thyreoglossus, e Sinus cervicalis

Head end of

human embryo, about the end of the fourth week. (From model by Peter.)

Floor of

pharynx of human embryo about twenty-six days old. (From model by Peters.)

Branchial

cleft anomalies: a pictorial review of embryological development and spectrum of imaging findings. Frontal schematic representation of a 5-mm human embryo at the fifth week of gestation. Sagittal sections taken through the branchial apparatus demonstrate the anatomic relationship of external clefts and internal pouches as well as the derivation of important head and neck structures. The sixth arch is very small and not visualised as a separate, discrete structure from pouch 4/5 in Fig. 1. [Reproduced with permission from Waldhausen J (2006) Branchial cleft and arch anomalies in children. Seminars in Pediatric Surgery 15:64–69]