Head and Face Development
DrAnnemiekBeverdam– SchoolofMedicalSciences,UNSWWallaceWurth BuildingRoom234– [email protected]
Resources:http://php.med.unsw.edu.au/embryology/
Larsen’s Human EmbryologyThe Developing Human: Clinically Oriented Embryology
Lecture overviewHead and Face Development
Embryonic tissues contributing to cranial developmentCraniofacial Development
Branchial/Pharyngeal Arch Derivatives:- Skeleton- Arteries- Muscles
- Cranial Nerves- Clefts/pouches
Development of the PituitaryDevelopment of the TongueCraniofacial abnormalities
DrAnnemiekBeverdam– SchoolofMedicalSciences,UNSWWallaceWurth BuildingRoom234– [email protected]
Resources:http://php.med.unsw.edu.au/embryology/
Larsen’s Human EmbryologyThe Developing Human: Clinically Oriented Embryology
End product gastrulation:Trilaminar embryo
Ectoderm (Neural crest)brain, spinal cord, eyes, peripheral nervous system
epidermis of skin and associated structures, melanocytes, cranial connective tissues (dermis)
Mesodermmusculo-skeletal system, limbs,
connective tissue of skin, organs and cranium,urogenital system, heart, blood cells
Endodermepithelial linings of gastrointestinal, liver, pancreas,
thyroid and respiratory tracts
Embryonic tissues contributing to cranial development
EctodermandNeuralCrestParaxialMesoderm
Endoderm
Week4embryo
Cranial Ectoderm and Neural CrestEmbryonic tissues contributing to cranial development
Embryonic tissues contributing to cranial developmentCranial Neural Crest
Cranialneuralcrest:Cranialmesenchyme,facialskeleton,cranialnerveganglia
Cardiacneuralcrest:Melanocytes,cartilage,connectivetissueandneuronsofsomepharyngealarches,Contributestoformationofregionsoftheheart
Trunkneuralcrest:Melanocytes,dorsalrootganglia,sympatheticganglia,adrenalmedulla,nervessurroundingaorta
VagalandSacralneuralcrest:Melanocytes,gangliaoftheentericnervoussystemParasympatheticganglia
Embryonic tissues contributing to cranial developmentParaxialMesoderm
Cranial:Unsegmentedparaxialmesoderm:headmesenchyme
Trunk:Segmentedparaxialmesoderm:somites
Embryonic tissues contributing to cranial developmentEndoderm
Bucchopharyngeal membraneLiningofthepharyngealandlaryngealcavities
Craniofacial Development
Craniofacial DevelopmentHumansdevelop6pharyngealorbranchialarches(BA)
Formfromrostrally tocaudallyBA1givesrisetomaxillaryandmandibularprocess
BA5disappears
Craniofacial DevelopmentEachbranchialarchinitiallyconsistsof:Ectoderm,endodermandmesoderm
Pharyngealpouch(endoderm)Pharyngealgroove/cleft(ectoderm)
Eacharchgivesriseto:Cartilage,Artery,Muscle,CranialNerve
Craniofacial Development
Facial DevelopmentFacialprimordiaappearinweek4
Frontonasalprocessandnasalplacodes1st branchialarch:mandibularandmaxillaryprocesses
Stomodeum
Craniofacial Development
Facial development
https://embryology.med.unsw.edu.au/embryology/images/d/dd/Face_001.mp4
Craniofacial Development
Craniofacial DevelopmentPalate and nasal cavities
https://embryology.med.unsw.edu.au/embryology/images/8/8f/Palate_001.mp4https://embryology.med.unsw.edu.au/embryology/images/7/78/Palate_002.mp4
Facial DevelopmentPalate and nasal cavities
https://www.youtube.com/watch?v=DgZ_tqucdI4
Pharyngeal/Branchial Arch DerivativesSkeletalderivatives
ArteriesMuscleNerve
Cleft/Pouches
Frontonasalprocess:frontalbone,nasalbonesandseptum,lacrimalbones,nasallabyrinthsBA1Maxillaryprocess:maxilla,palatine,vomer,zygomaticbone,parttemporalboneBA1Mandibularprocess:Meckel’scartilageandmandible,malleusandincusBA2:Reichert’scartilageandhyoid(superiorpart),andstapesBA3:Hyoid(inferiorpart)BA4:laryngealcartilages:thyroidandcricoidcartilage
Frontal
Pharyngeal/Branchial Arch DerivativesSkeletal derivatives
Blue:Cranialneuralcrest-derivedbones(FNP,BA1andBA2):mostofviscerocraniumRed:Paraxialmesodermderivedbones:mostofneurocranium
Yellow:BA2-derived
Pharyngeal/Branchial Arch DerivativesSkeletal derivatives
Pharyngeal/Branchial Arch DerivativesMiddle ear ossicles and laryngeal cartilages
OssificationTwotypes:1.Endochondralossification:
MostofourskeletonBonereplacescartilagetemplate
2.Intramembranousossification:Flatbones(calvaria)Directossificationfrommesenchyme
Intramembranous Ossification
Endochondral Ossification
Pharyngeal/Branchial Arch DerivativesArteries
BA1- mainlylost,formpartofmaxillaryarteryBA2– mainlylost,stapedial arteriesBA3- commoncarotidarteries,internalcarotidarteriesBA4- leftformspartofaorticarch,rightformspartrightsubclavianarteryBA5- mainlylostBA6- leftformspartofleftpulmonaryartery,rightformspartofrightpulmonaryartery
Pharyngeal/Branchial Arch DerivativesBranchial muscles
BA1- musclesofmastication,mylohyoid,tensortympanic,ant.bellydigastricBA2- musclesoffacialexpression,stapedius,stylohyoid,post.bellydigastricBA3- stylopharyngeusBA4&6- crycothyroid,pharynxconstrictors,larynxmuscles,oesophagus (st. muscle)
Pharyngeal/Branchial Arch DerivativesCranial nerves
BA1- CranialNerveV:trigeminalnerveBA2- CranialNerveVII:facialnerveBA3- CranialNerveIX:glossopharyngealnerveBA4&6- CranialNerveX:vagus nerve
Pharyngeal/Branchial Arch Derivatives1st branchial cleft/pouch
1st pouch:tubotympanic recess:tympaniccavity,eustachian tube1st cleft:externalacousticmeatus
Pharyngeal/Branchial Arch Derivatives1st branchial cleft/pouch
BA1- elongatestoformtubotympanic recess,tympaniccavity,mastoidantrum,eustachian tubeBA2- formstonsillarsinus,mostlyobliteratedbypalatinetonsilBA3- formsinferiorparathyroid andthymusBA4- formssuperiorparathyroid,parafollicular cellsofthyroid
Development of the Pituitary
Twoembryonicorigins:1.Ectodermoforalcavity:Rathke’s pouch:adenohypophysis2.Floorofdiencephalon:neurohypophysis
Development of the Tongue
Contributionsinitiallyfromallarches:Arch1- oralpartoftongue(ant3/2)(lingualswellingandtuberculumimpar)Arch2- initialcontributiontosurfaceislostArch3- pharyngealpartoftongue(post1/3)Arch4- epiglottisandadjacentregions
Tongueisinnervatedbymusclesderivedfromsclerotomes
Craniofacial AbnormalitiesCleft Lip/Palate
Craniofacial AbnormalitiesTreacher Collins Syndrome
AutosomalDominantAffectsCranialneuralcrestmigration
BA1hypoplasiaAbnormaldevelopmentofstructuresderivedofBA1
Craniofacial AbnormalitiesPierre Robin Syndrome
BA1syndromeCleftPalateRetrognathia
Craniofacial AbnormalitiesDiGeorge Syndrome
Disturbanceofcervicalneuralcrestmigration:3rdand4thpouchdonotform:absenceofthymusandparathyroidglands
Craniofacial AbnormalitiesFetal Alcohol Syndrome
AlcoholconsumptioninearlydevelopmentCausesfacialandneurologicalabnormalities
Lecture overviewHead and Face Development
Embryonic tissues contributing to cranial developmentCraniofacial Development
Branchial/Pharyngeal Arch Derivatives:- Skeleton- Arteries- Muscles
- Cranial Nerves- Clefts/pouches
Development of the PituitaryDevelopment of the TongueCraniofacial abnormalities
DrAnnemiekBeverdam– SchoolofMedicalSciences,UNSWWallaceWurth BuildingRoom234– [email protected]
Resources:http://php.med.unsw.edu.au/embryology/
Larsen’s Human EmbryologyThe Developing Human: Clinically Oriented Embryology