Pharangeal arch derivatives

jambomber's version from 2015-05-21 11:12


Question Answer
Give some examples of human congenital defectsCleft lip (~1:1,000 births), Micrognathia
Why is craniofacial dev so complexCraniofacial development comprises a complex sequence of morphogenetic and differentiative events; depends upon interactions between endoderm, ectoderm, mesoderm and neural crest cells
What does arch 2 pouch formPalatine tonsil
What does pouch 3 form?Inferior parathyroid+ Thymus
What does pouch 4 formSuperior parathyroid + Ultimobranchial body
What is the structure of the TympanumBilayered contact between pouch endo with cleft ecto
What does development of thyroid involveForms @ base of the tongue and migrates down twd larynx
What cell types in thyroidFollicular cells: secrete T3 and T4 hormones (endodermal origin) Parafollicular cells: secrete calcitonin, originate in the ultimobranchial bodies (neural crest origi
Where do parathyoids come to reside- what cell types withChief cells and oxyphil cells secrete parathyroid hormone, parathyroid hormone-related protein
What cells make up the thymus- where do they originate fromThymovytes from meoderm and endododermal epithilial reticular cells
What happens to remanants of 3-4 cleftsForm cervical sinus which is eventually close
What causes external branch fistulaFailure of cleft closure
How can an internal fistula arise?Peforation of cevical sinus cyst with pouch 2
What morpho movement occurs in cleft region?the 2 nd arch expands caudally, and fuses with the 5 th arch (forming a cervical sinus)
What cell pops reside within archesParaxial mesoderm and NCCS
What are the crainofacial msleExtra-ocular muscles 2. Pharyngeal arch muscles 3. Laryngoglossal muscles 4. Axial muscles
Where do Extra-ocular and pharyngeal arch muscles originate?discrete populations of prechordal and cranial paraxial mesoderm
Where does pharangeal arch mesoderm form?At the core of pharangeal arches
Where do tongue muscles originateExtrinsic and intrinsic tongue muscles derive from myotome of somites 1-5
What is the evidence that craniofacial skeleton primrarily from NCAblation studies 2. Chick-quail chimaera experiments 3. Cre Lox lineage tracing in mice
What are the steps of facial morphogenesis1. Delineation of the medial and lateral nasal processes (by the nasal pits) 2. Fusion of the medial nasal processes to form the primary palate 3. Fusion of the maxillary prominence with the medial and lateral nasal processes 4. Fusion of the secondary palatal shelves (derived from the maxillary prominences) with the primary palate.