abnormal third pharyngeal pouch morphology absent third pharyngeal pouch MP:0013226 MPheno.ontology absence of the third endodermal branchial pouch, normally located between the third and fourth branchial arches; in mammals, the cranial dorsal aspect of the third pouch generates the inferior parathyroids (or parathyroid III), whereas the caudal ventral part of the pouch gives rise to the thymus epithelium absent 3rd branchial pouch absent 3rd pharyngeal pouch absent third branchial pouch