Head Development: Difference between revisions
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== Introduction == | == Introduction == | ||
[[File:Fetal_head_lateral.jpg|thumb|300px|Fetal head (week 12)]] | [[File:Fetal_head_lateral.jpg|thumb|300px|Fetal head (week 12)]] | ||
The head and neck are one of the most complicated structures that the embryo forms, with special intermediate structures (the pharyngeal | The {{head}} and neck is not really a "system", but structurally quite different in origin from the body. The head and neck are one of the most complicated structures that the embryo forms, with special intermediate structures (the {{pharyngeal arch}}) and contributions from all 3 embryonic layers ({{ectoderm}}, {{mesoderm}}, {{endoderm}}), and significantly, a major contribution from the {{neural crest}}. Neural crest contributes jaw skeletal elements, connective tissues and tendons. The associated muscles derive mainly from cranial mesoderm. These components though will form different structures dependent upon which arch they are within. The cavity within the pharyngeal arches forms the [[P#pharynx|pharynx]]. | ||
The pharynx contributes to 2 endocrine organs, in the roof the pituitary (hypophysis) and the floor the thyroid. The thyroid gland being one of the first endocrine organs to be formed has an important role in embryonic development. The pharynx floor of all arches also contribute to the formation of the tongue. | The pharynx contributes to 2 endocrine organs, in the roof the {{pituitary}} (hypophysis) and the floor the {{thyroid}}. The thyroid gland, being one of the first endocrine organs to be formed, has an important role in embryonic development. The pharynx floor of all arches also contribute to the formation of the {{tongue}}. | ||
{{ | Because the head contains many different structures also review notes on: {{skull}}, {{sensory}} ({{placode}}, {{vision}}, {{hearing}}, {{smell}}, {{taste}}), {{respiratory}} ([[Respiratory_System_-_Upper_Respiratory_Tract|pharynx]]), {{integumentary}}({{tooth}}, {{hair}}) and {{endocrine}} ({{pituitary}}, {{thyroid}}, {{parathyroid}}, {{thymus}}). | ||
{{Head Links}} | |||
== Some Recent Findings == | == Some Recent Findings == | ||
{| | |||
|-bgcolor="F5FAFF" | |||
| | |||
* '''Review - MR Imaging of the Fetal Face'''{{#pmid:29652578|PMID29652578}} "The human face is a complex anatomic structure with an equally complex embryologic development. Derangement of the developmental process can result in various structural anomalies, which range from a mainly cosmetic deformity, such as cleft lip, to potentially life-threatening conditions such as arhinia. These anomalies (a) can occur as isolated anomalies; (b) can be associated with intracranial, spinal, or dental anomalies; or (c) can be a part of various syndromes, thus serving as diagnostic clues in such cases. Proper evaluation of fetal facial deformities can help in prognostication, family counseling, and prenatal or early postnatal intervention. Ultrasonography (US) is the first line of investigation in these cases. However, when US does not allow complete evaluation of these anomalies owing to its inherent limitations, magnetic resonance (MR) imaging allows comprehensive evaluation of the anomaly itself and also evaluation of various associations and the treatment approach. The embryology of the fetal facial structures is considered with regard to the MR imaging technique and the MR imaging anatomy. The MR imaging features of various structural anomalies are described and classified into six groups, namely, orofacial clefts, orbital anomalies, nasal anomalies, facial masses, external ear anomalies, and abnormal face shape or profile." [[Magnetic Resonance Imaging]] | |||
* '''Branchial anomalies in children: A report of 105 surgical cases'''{{#pmid:29287855|PMID29287855}} "Branchial anomalies (BAs) account for 20% of all congenital masses in children. We sought to review the incidence of involvement of individual anomalies, diagnostic methods, surgical treatment, and complications of BAs in children. ...A total of 33 (31.4%) cases presented with first BAs, 13 (12.4%) presented with second BAs, and 59 (56.2%) presented with third and fourth BAs, including 6 cases of congenital lower neck cutaneous fistula." | |||
|} | |||
{| class="wikitable mw-collapsible mw-collapsed" | |||
! More recent papers | |||
|- | |||
| [[File:Mark_Hill.jpg|90px|left]] {{Most_Recent_Refs}} | |||
Search term: [http://www.ncbi.nlm.nih.gov/pubmed/?term=Head+Development ''Head Development''] | [http://www.ncbi.nlm.nih.gov/pubmed/?term=Pharyngeal+Arch+Development ''Pharyngeal Arch Development''] | [http://www.ncbi.nlm.nih.gov/pubmed/?term=Skull+Development ''Skull Development''] | [http://www.ncbi.nlm.nih.gov/pubmed/?term=Face+Development ''Face Development''] | | |||
|} | |||
{| class="wikitable mw-collapsible mw-collapsed" | |||
! Older papers | |||
|- | |||
| {{Older papers}} | |||
* '''Developmental and evolutionary origins of the pharyngeal apparatus'''{{#pmid:23020903|PMID23020903}} "The vertebrate pharyngeal apparatus, serving the dual functions of feeding and respiration, has its embryonic origin in a series of bulges found on the lateral surface of the head, the pharyngeal arches. Developmental studies have been able to discern how these structures are constructed and this has opened the way for an analysis of how the pharyngeal apparatus was assembled and modified during evolution. For many years, the role of the neural crest in organizing pharyngeal development was emphasized and, as this was believed to be a uniquely vertebrate cell type, it was suggested that the development of the pharyngeal apparatus of vertebrates was distinct from that of other chordates." | |||
* '''hand2 and Dlx genes specify dorsal, intermediate and ventral domains within zebrafish pharyngeal arches.'''{{#pmid:20573696|PMID20573696}} "The ventrally expressed secreted polypeptide endothelin1 (Edn1) patterns the skeleton derived from the first two pharyngeal arches into dorsal, intermediate and ventral domains. ...Collectively, our work indicates that the expression and function of hand2 and Dlx genes specify major patterning domains along the dorsoventral axis of zebrafish pharyngeal arches." | |||
|} | |||
== Textbooks == | == Textbooks == | ||
[[File:Pharyngeal_arch_cartilages.jpg|thumb]] | [[File:Pharyngeal_arch_cartilages.jpg|thumb]] | ||
* '''The Developing Human: Clinically Oriented Embryology''' (8th Edition) by Keith L. Moore and T.V.N Persaud - Moore & Persaud Chapter Chapter 10 The Pharyngeal Apparatus pp201 - 240. | * '''The Developing Human: Clinically Oriented Embryology''' (8th Edition) by Keith L. Moore and T.V.N Persaud - Moore & Persaud Chapter Chapter 10 The Pharyngeal Apparatus pp201 - 240. | ||
* '''Larsen’s Human Embryology''' by GC. Schoenwolf, SB. Bleyl, PR. Brauer and PH. Francis-West - Chapter 12 Development of the Head, the Neck, the Eyes, and the Ears pp349 - 418. | * '''Larsen’s Human Embryology''' by GC. Schoenwolf, SB. Bleyl, PR. Brauer and PH. Francis-West - Chapter 12 Development of the Head, the Neck, the Eyes, and the Ears pp349 - 418. | ||
{| class="wikitable mw-collapsible mw-collapsed" | |||
! colspan=6|[[Movies#Head_and_Face|Head Movies]] | |||
|- | |||
| colspan=5|{{Head_cartoons}} | |||
| valign="bottom"|{{Endoderm movie}} | |||
|- | |||
| valign="bottom"|{{Human Stage16-18 face}} | |||
| valign="bottom"|{{Template:Human_Stage15-22_head}} | |||
| valign="bottom"|{{Stage 23 MRI movie 1}} | |||
| valign="bottom"|{{Fetal week 10 palate movie}} | |||
| valign="bottom"|{{Mouse cranial neural crest movie}} | |||
| valign="bottom"|{{Mouse face microCT movie}} | |||
|} | |||
{| class="wikitable mw-collapsible mw-collapsed" | |||
! UNSW Students | |||
|- | |||
| [[File:Mark_Hill_icon.jpg|50px]] | |||
| You have access the following online Embryology textbooks through the UNSW Library. | |||
|- | |||
| [[File:The Developing Human, 8th edn.jpg|80px]] | |||
| Moore, K.L. & Persuad, T.V.N. (2008). <i>The Developing Human: clinically oriented embryology</i> (8<sup>th</sup> ed.). Philadelphia: Saunders. | |||
The following chapter links only work with a UNSW connection. | |||
* [http://www.unsw.eblib.com.wwwproxy0.library.unsw.edu.au/patron/Read.aspx?p=1430154&pg=181 Chapter 9 Pharyngeal Apparatus, Face, and Neck] | |||
* [http://www.unsw.eblib.com.wwwproxy0.library.unsw.edu.au/patron/Read.aspx?p=1430154&pg=451 Chapter 18 Development of Eyes and Ears] | |||
|- | |||
|} | |||
==Objectives== | ==Objectives== | ||
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* Briefly summarise the development of the tongue. | * Briefly summarise the development of the tongue. | ||
==The Pharynx== | ==The Pharynx== | ||
[[File:Head arches cartoon.jpg|300px]] | [[File:Head arches cartoon.jpg|300px]] | ||
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== Pharyngeal Arch Components == | == Pharyngeal Arch Components == | ||
[[File:Stage13 oral cavity floor02.jpg|thumb|alt=Human embryo Stage 13 oral cavity floor|Human embryo pharyngeal arches (Stage 13 oral cavity floor)]] | |||
Major features to identify for each: '''arch''', '''pouch''', '''groove''' and '''membrane'''. Contribute to the formation of head and neck and in the human appear at the 4th week. The first arch contributes the majority of upper and lower jaw structures. | Major features to identify for each: '''arch''', '''pouch''', '''groove''' and '''membrane'''. Contribute to the formation of head and neck and in the human appear at the 4th week. The first arch contributes the majority of upper and lower jaw structures. | ||
==Early Face and Pharynx == | ==Early Face and Pharynx == | ||
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===Neural Crest === | ===Neural Crest === | ||
* Mesenchyme invaded by neural crest generating connective tissue components | * Mesenchyme invaded by {{neural crest}} generating connective tissue components | ||
* cartilage, bone, ligaments | * cartilage, bone, ligaments | ||
* arises from midbrain and hindbrain region | * arises from midbrain and hindbrain region | ||
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==Arch Arteries== | ==Arch Arteries== | ||
{| | |||
| | |||
* Arch 1 - mainly lost, form part of maxillary artery | * Arch 1 - mainly lost, form part of maxillary artery | ||
* Arch 2 - stapedial arteries | * Arch 2 - stapedial arteries | ||
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* Arch 4 - left forms part of aortic arch, right forms part right subclavian artery | * Arch 4 - left forms part of aortic arch, right forms part right subclavian artery | ||
* Arch 6 - left forms part of left pulmonary artery , right forms part of right pulmonary artery | * Arch 6 - left forms part of left pulmonary artery , right forms part of right pulmonary artery | ||
placental vein -> liver -> heart -> truncus arteriosus -> aortic sac -> '''arch arteries''' -> dorsal aorta -> placental artery | placental vein -> liver -> heart -> truncus arteriosus -> aortic sac -> '''arch arteries''' -> dorsal aorta -> placental artery | ||
| [[File:Congdon1922-34.jpg|250px|link=Book - Contributions to Embryology Carnegie Institution No.68]] | |||
Human embryo (5mm, lateral view) showing pulmonary arteries | |||
|} | |||
{| class="wikitable mw-collapsible mw-collapsed" | |||
! Arch 5 Artery? | |||
|- | |||
| [[File:Mark Hill.jpg|80px|left]]There has been ongoing controversy as to whether the fifth arch artery, that forms in fish, ever develops in birds and mammals. A recent study in mouse and human embryos identified the presence of an extra vessel presence in a single [[Carnegie stage 14|Carnegie Stage 14]] human embryo.{{#pmid:22623372|PMID22623372}} | |||
|} | |||
{{Congdon1922 collapse table1}} | |||
==Arch Cartilage== | ==Arch Cartilage== | ||
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* Arch 4&6 - crycothyroid, pharynx constrictors, larynx muscles, oesophagus (st. muscle) | * Arch 4&6 - crycothyroid, pharynx constrictors, larynx muscles, oesophagus (st. muscle) | ||
[[File:Head and heart muscle cartoon.jpg|400px]] | |||
Head and Heart Muscle{{#pmid:25903628|PMID25903628}} On the left side of the body (right part of figure) the facial expression muscles have been removed to show the masticatory muscles. | |||
<gallery mode="packed-hover"> | |||
File:Gray1024.jpg|Masseter | |||
File:Gray1028.jpg|Stylopharyngeus | |||
File:Gray1030.jpg|Pharynx constrictors | |||
</gallery> | |||
==Arch Nerve== | ==Arch Nerve== | ||
* Arch 1 - CN V trigeminal, caudal 2/3 maxillary and mandibular, cranial 1/3 sensory nerve of | [[File:Gray0778.jpg|thumb|trigeminal]] | ||
* Arch 1 - CN V trigeminal, caudal 2/3 maxillary and mandibular, cranial 1/3 sensory nerve of head and neck, mastication motor | |||
* Arch 2 - CN VII facial | * Arch 2 - CN VII facial | ||
* Arch 3 - CN IX glossopharyngeal | * Arch 3 - CN IX glossopharyngeal | ||
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==Thyroid Gland == | ==Thyroid Gland == | ||
* not a pouch structure | * not a pouch structure | ||
* first endocrine organ to develop day 24 | * first endocrine organ to develop day 24 | ||
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* paired maxillary prominences - form upper cheek and upper lip | * paired maxillary prominences - form upper cheek and upper lip | ||
* paired mandibular prominences - lower cheek, chin and lower lip | * paired mandibular prominences - lower cheek, chin and lower lip | ||
==Frontonasal Process== | |||
[[File:Stage18_em11.jpg|thumb|Frontonasal prominence (Week 7, 44 - 48 days, CRL 13 - 17 mm)]] | |||
The frontonasal process (FNP) forms the majority of the superior part of the early face primordia. It later fuses with the maxillary component of the first pharyngeal arch to form the upper jaw. Failure of this fusion event during the embryonic period leads to cleft lip. Under the surface ectoderm the process mesenchyme consists of two cell populations; neural crest cells, forming the connective tissues; and the mesoderm forming the endothelium of the vascular network. | |||
A chicken developmental model study has identified a specific surface region, the Frontonasal Ectodermal Zone (FEZ), initially induced by bone morphogenetic proteins that appears to regulate the future growth and patterning of the frontonasal process. The specific frontonasal ectodermal zone was located in the frontonasal process ectoderm flanking a boundary between Sonic hedgehog (Shh) and Fibroblast growth factor 8 (Fgf8) expression domains.{{#pmid:18028903|PMID18028903}} | |||
==Head/Skull== | ==Head/Skull== | ||
{| | |||
| | |||
* chondrocranium forms base of skull | * chondrocranium forms base of skull | ||
* in lower vertebrates encases brain | * in lower vertebrates encases brain | ||
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* calveria | * calveria | ||
* facial skeleton | * facial skeleton | ||
* pharyngeal arches | * pharyngeal arches | ||
| {{Adult skull movies}} | |||
|} | |||
==Sensory Placodes == | ==Sensory Placodes == | ||
[[File:Stage14 sem2a-limb.jpg|thumb|Sensory placodes (week 5)]] | |||
* During week 4 a series of thickened surface ectodermal patches form in pairs rostro-caudally in the head region. | * During week 4 a series of thickened surface ectodermal patches form in pairs rostro-caudally in the head region. | ||
* Recent research suggests that all sensory placodes may arise from common panplacodal primordium origin around the neural plate, and then differentiate to eventually have different developmental fates. | * Recent research suggests that all sensory placodes may arise from common panplacodal primordium origin around the neural plate, and then differentiate to eventually have different developmental fates. | ||
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lies on the surface, adjacent to the outpocketing of the nervous system (which will for the retina) and will form the lens. | lies on the surface, adjacent to the outpocketing of the nervous system (which will for the retina) and will form the lens. | ||
:'''Links:''' [[Vision - Lens Development|Lens Development]] | |||
===Nasal placode=== | ===Nasal placode=== | ||
has 2 components (medial and lateral) and will form the nose | has 2 components (medial and lateral) and will form the nose olfactory epithelium. | ||
:'''Links:''' [[Sensory - Smell Development|Smell Development]] | [[Placodes]] | |||
==Head Growth== | ==Head Growth== | ||
[[File:Skull CT normal sutures.jpg|thumb|Developing skull [[Computed Tomography]] (CT) image showing normal sutures.]] | |||
* continues postnatally - fontanelle allow head distortion on birth and early growth | * continues postnatally - fontanelle allow head distortion on birth and early growth | ||
* bone plates remain unfused to allow growth, puberty growth of face | * bone plates remain unfused to allow growth, puberty growth of face | ||
[[File:Fetal_head_growth_circumference_graph01.jpg|600px]] | |||
Fetal head growth (circumference) | |||
<gallery> | |||
File:Fetal_head_growth_circumference_graph01.jpg|Second and third trimesters | |||
File:Fetal_head_growth_circumference_graph02.jpg|Second trimester | |||
</gallery> | |||
===Skull Overview=== | ===Skull Overview=== | ||
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Calveria - bone has no cartilage (direct ossification of mesenchyme) | Calveria - bone has no cartilage (direct ossification of mesenchyme) | ||
* bones do not fuse, fibrous sutures 1. allow distortion to pass through birth canal 2. allow growth of the brain | * bones do not fuse, fibrous sutures 1. allow distortion to pass through birth canal 2. allow growth of the brain | ||
* 6 fontanelles, posterior closes at 3 months, anterior closes at 18 months | * 6 fontanelles, posterior closes at 3 months, anterior closes at 18 months | ||
:'''Links:''' [[Musculoskeletal System - Skull Development|Skull Development]] | |||
==Palate== | ==Palate== | ||
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Secondary palate, fusion in the human embryo in week 9. This requires the early palatal shelves growth, elevation and fusion during the early embryonic period. The fusion event is to both each other and the primary palate. [[:File:Palatal shelves animation.gif|palatal shelf elevation]] | [[:File:palate.gif|secondary palate]] | Secondary palate, fusion in the human embryo in week 9. This requires the early palatal shelves growth, elevation and fusion during the early embryonic period. The fusion event is to both each other and the primary palate. [[:File:Palatal shelves animation.gif|palatal shelf elevation]] | [[:File:palate.gif|secondary palate]] | ||
:'''Links:''' {{Palate}} | |||
==Ear Auricles== | ==Ear Auricles== | ||
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** Arch 3 - pharyngeal part of tongue (post 1/3) | ** Arch 3 - pharyngeal part of tongue (post 1/3) | ||
** Arch 4 - epiglottis and adjacent regions | ** Arch 4 - epiglottis and adjacent regions | ||
===Tongue muscle=== | ===Tongue muscle=== | ||
[[File:Tongue-muscle.jpg|thumb|tongue muscle]] | [[File:Tongue-muscle.jpg|thumb|tongue muscle]] | ||
* Tongue muscles originate from the somites. Tongue muscles develop before masticatory muscles and is completed by birth. | * Tongue muscles originate from the somites. | ||
* Masticatory muscles originate from the somitomeres. These muscles develop late and are not complete even at birth. | ** Tongue muscles develop before masticatory muscles and is completed by birth. | ||
* Masticatory muscles originate from the somitomeres. | |||
** These muscles develop late and are not complete even at birth. | |||
===Salivary Glands=== | ===Salivary Glands=== | ||
* epithelial buds in oral cavity ( | * epithelial buds in oral cavity (week 6 to 7) extend into mesenchyme | ||
* parotid, submandibular, sublingual | * parotid, submandibular, sublingual | ||
| | :'''Links:''' [[Salivary Gland Development]] | [[Tongue Development]] | [[Development Animation - Tongue]] | ||
| [[ | |||
==Pharyngeal Arch Tables== | |||
{{Pharyngeal Arch table}} | |||
=== Structures derived from Pouches === | === Structures derived from Pouches === | ||
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{| class="prettytable" | {| class="prettytable" | ||
| <center>''' | | <center>'''Pouch'''</center> | ||
| '''Overall Structure''' | | '''Overall Structure''' | ||
| '''Specific Structures''' | | '''Specific Structures''' | ||
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==Movies== | ==Movies== | ||
There are a number of movies representing development of different features of the [[Movies#Head_and_Face|head and face]]. | |||
{{Head_cartoons}} | |||
:'''Links:''' [[Movies#Head_and_Face|Head and Face Movies]] | [[Movies]] | |||
== References == | == References == | ||
<references/> | <references/> | ||
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===Reviews=== | ===Reviews=== | ||
{{#pmid:32670926}} | |||
{{#pmid:29652578}} | |||
{{#pmid:29616744}} | |||
{{#pmid:26924989}} | |||
{{#pmid:20607135}} | |||
{{#pmid:20144910}} | |||
===Articles=== | ===Articles=== | ||
{{#pmid:25748249}} | |||
{{#pmid:25201771}} | |||
{{#pmid:24130849}} | |||
===Search PubMed=== | ===Search PubMed=== | ||
Search | Search term: [http://www.ncbi.nlm.nih.gov/pubmed/?term=Head+Development ''Head Development''] | [http://www.ncbi.nlm.nih.gov/pubmed/?term=Pharyngeal+Arch+Development ''Pharyngeal Arch Development''] | | [http://www.ncbi.nlm.nih.gov/pubmed/?term=Face+Development ''Face Development''] | ||
{{References footer}} | |||
===Books=== | |||
Hinrichsen K. The early development of morphology and patterns of the face in the human embryo. Berlin ; New York : Springer-Verlag, c1985 | |||
==Additional Images== | ==Additional Images== | ||
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File:Musculoskeletal-_adult_mandible.jpg|adult mandible | File:Musculoskeletal-_adult_mandible.jpg|adult mandible | ||
File:Musculoskeletal-_adult_hyoid.jpg|adult hyoid | File:Musculoskeletal-_adult_hyoid.jpg|adult hyoid | ||
</gallery> | |||
===Historic=== | |||
{{Historic Disclaimer}} | |||
[[Book_-_Human_Embryology_and_Morphology_1|Development or the Face]] | |||
<gallery> | |||
File:Keith1902 fig001.jpg|Fig. 1. Showing the formation of the face by the Nasal, Maxillary, and Mandibular processes in an embryo of the 4th week. | |||
File:Keith1902 fig002.jpg|Fig. 2. Showing the parts of the face formed from the Nasal, Maxillary and Mandibular processes. | |||
File:Keith1902 fig003.jpg|Fig. 3. Showing the structures formed in the Mesial Nasal Processes. | |||
File:Keith1902 fig004.jpg|Fig. 4. Showing the trough-shaped Vomer of the newly born. | |||
File:Keith1902 fig005.jpg|Fig. 5. Showing the suture on the face between the premaxilla and maxilla in the skull of a young orang. | |||
File:Keith1902 fig006.jpg|Fig. 6. Showing the structures formed in the Lateral Nasal Processes. | |||
File:Keith1902 fig007.jpg|Fig. 7. Coronal section of the skull of a 7th month human foetus to show the cartilages of the Lateral and Mesial Nasal Processes and the bones formed round them. | |||
File:Keith1902 fig008.jpg|Fig. 8. Showing the ingrowth of the palatal plates of the two maxillary processes early in the 2nd month. (After Kollmann.) . | |||
File:Keith1902 fig009.jpg|Fig. 9. Showing the Hard Palate at birth. The premaxillary part is formed from the Mesial Nasal Processes ; the remainder by the Palatal Plates of the Maxillary Processes. | |||
File:Keith1902 fig010a-c.jpg|Fig. 10, a, b, c. Showing what become of the skeletons of the Mandibular Arch (Meckel's Cartilage) and Maxillary Process (Palato-quadrate Cartilage). | |||
File:Keith1902 fig010d.jpg|Fig. 10 D. Illustrating Gadow's view of the origin of the Auditory Ossicles and Tympanic Plate. | |||
File:Keith1902 fig011.jpg|Fig. 11. Showing the manner in which the development of the Maxillary Antrum affects the size of the palate and position of the molar teeth. | |||
File:Keith1902 fig012.jpg|Fig. 12. Showing the Centres of Ossification and age changes in the Lower Jaw. | |||
File:Keith1902 fig013.jpg|Fig. 13. The chief types of the Temporo-Maxillary Articulation. '''A.''' Carnivorous Type. '''B.''' Omnivorous Type. '''C.''' Herbivorous Type. | |||
File:Keith1902 fig014.jpg|Fig. 14. Showing the Chief Changes after birth in the form of the TemporoMaxillary Articulation. | |||
File:Keith1902 fig015a.jpg|Fig. 15 A. Sagittal Section showing the Stomodaeum and position of the Oral Plate in the 3rd week. | |||
File:Keith1902 fig015b.jpg|Fig. 15 B. Showing the parts of the Buccal and Nasal Cavities formed from the Stomodaeum. The relative position of the Oral Plate is indicated. | |||
</gallery> | |||
[[Book_-_Human_Embryology_and_Morphology_3|Development of the Pharynx and Neck]] | |||
<gallery> | |||
File:Keith1902 fig021a.jpg|Fig. 21a. Showing the Visceral Arches and Cleft-depressions in the Pharyngeal Wall of a 4th week human Embryo. Each Visceral Arch contains an Aortic Arch. (After His.) | |||
File:Keith1902 fig021b.jpg|Fig. 21b. Showing the position of the Heart, Visceral and Aortic Arches in a fish. (Diagrammatic — after Gegenbaur.) | |||
File:Keith1902 fig022.jpg|Fig. 22. Showing the Primitive Pharynx of a 3rd week embryo in sagittal section, bounded by the Visceral Arches. (After His.) . | |||
File:Keith1902 fig023.jpg|Fig. 23. Showing the Floor of the Pharynx of a 4th week human embryo. (After His.) | |||
File:Keith1902 fig024.jpg|Fig. 24. Schematic Section of a Visceral Arch. | |||
File:Keith1902 fig025.jpg|Fig. 25. Showing the position of the External Cleft Depressions in the Adult. | |||
File:Keith1902 fig026.jpg|Fig. 26. Showing what become of the Cartilages of the Visceral Arches. | |||
File:Keith1902 fig027.jpg|Fig. 27. Showing what become of the Nerves of the Visceral Arches, hyoid arch) is represented by the chorda tympani and great superficial petrosal. | |||
File:Keith1902 fig028.jpg|Fig. 28. Showing what become of the Aortic Arches in the adult. Only the shaded parts persist. | |||
File:Keith1902 fig029.jpg|Fig. 29. The condition of the Eight and Left Doral Aortae in a 6th week human foetus. | |||
File:Keith1902 fig030.jpg|Fig. 30. Showing the Buccal and Pharyngeal parts of the Tongue. | |||
File:Keith1902 fig031.jpg|Fig. 31. Showing the origin of the tongue in the floor of the primitive pharynx. (After His.) | |||
File:Keith1902 fig032.jpg|Fig. 32. Showing the origin of the Submaxillary and Sublingual Glands from furrows between the gum and tongue during the flth week. (After His.) . | |||
File:Keith1902 fig033.jpg|Fig. 33. Showing the position of the Visceral Clefts in the Adult. | |||
File:Keith1902 fig034.jpg|Fig. 34. Showing the origin of the Tonsil, Thymus, and Thyroid from the Internal Cleft Recesses during the 4th week. (After His.). | |||
</gallery> | </gallery> | ||
==Terms== | ==Terms== | ||
{{Head terms}} | |||
<br> | |||
{{Palate terms}} | |||
{{ | {{Glossary}} | ||
==External Links== | |||
{{ | {{External Links}} | ||
* [http://orthodontics.cwru.edu/facialgrowth/text.htm Essentials of Facial Growth] Enlow and Hans | |||
{{Footer}} | |||
[[Category:System Development]] | [[Category:System Development]] |
Latest revision as of 12:44, 23 February 2022
Embryology - 15 Jun 2024 Expand to Translate |
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Introduction
The head and neck is not really a "system", but structurally quite different in origin from the body. The head and neck are one of the most complicated structures that the embryo forms, with special intermediate structures (the pharyngeal arch) and contributions from all 3 embryonic layers (ectoderm, mesoderm, endoderm), and significantly, a major contribution from the neural crest. Neural crest contributes jaw skeletal elements, connective tissues and tendons. The associated muscles derive mainly from cranial mesoderm. These components though will form different structures dependent upon which arch they are within. The cavity within the pharyngeal arches forms the pharynx.
The pharynx contributes to 2 endocrine organs, in the roof the pituitary (hypophysis) and the floor the thyroid. The thyroid gland, being one of the first endocrine organs to be formed, has an important role in embryonic development. The pharynx floor of all arches also contribute to the formation of the tongue.
Because the head contains many different structures also review notes on: skull, sensory (placode, vision, hearing, smell, taste), respiratory (pharynx), integumentary(tooth, hair) and endocrine (pituitary, thyroid, parathyroid, thymus).
Some Recent Findings
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More recent papers |
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This table allows an automated computer search of the external PubMed database using the listed "Search term" text link.
More? References | Discussion Page | Journal Searches | 2019 References | 2020 References Search term: Head Development | Pharyngeal Arch Development | Skull Development | Face Development | |
Older papers |
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These papers originally appeared in the Some Recent Findings table, but as that list grew in length have now been shuffled down to this collapsible table.
See also the Discussion Page for other references listed by year and References on this current page.
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Textbooks
- The Developing Human: Clinically Oriented Embryology (8th Edition) by Keith L. Moore and T.V.N Persaud - Moore & Persaud Chapter Chapter 10 The Pharyngeal Apparatus pp201 - 240.
- Larsen’s Human Embryology by GC. Schoenwolf, SB. Bleyl, PR. Brauer and PH. Francis-West - Chapter 12 Development of the Head, the Neck, the Eyes, and the Ears pp349 - 418.
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UNSW Students | |
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You have access the following online Embryology textbooks through the UNSW Library. | |
Moore, K.L. & Persuad, T.V.N. (2008). The Developing Human: clinically oriented embryology (8th ed.). Philadelphia: Saunders.
The following chapter links only work with a UNSW connection. |
Objectives
- List the main structures derived from the pharyngeal arches, pouches and clefts.
- Know the stages and structures involved in the development of the face.
- Predict the results of abnormal development of the face and palate.
- Briefly summarise the development of the tongue.
The Pharynx
The cavity within the pharyngeal arches forms the pharynx.
The pharynx contributes to 2 endocrine organs, in the roof the [endocrine7.htm pituitary] (hypophysis) and the floor the thyroid. The thyroid gland being one of the first endocrine organs to be formed has an important role in embryonic development. The pharynx floor of all arches also contribute to the formation of the [head6.htm tongue].
Pharyngeal Arch Components
Major features to identify for each: arch, pouch, groove and membrane. Contribute to the formation of head and neck and in the human appear at the 4th week. The first arch contributes the majority of upper and lower jaw structures.
Early Face and Pharynx
- Pharynx - begins at the buccopharyngeal membrane (oral membrane), apposition of ectoderm with endoderm (no mesoderm between)
Pharyngeal Arch Development
- branchial arch (Gk. branchia= gill)
- arch consists of all 3 trilaminar embryo layers
- ectoderm- outside
- mesoderm- core of mesenchyme
- endoderm- inside
Neural Crest
- Mesenchyme invaded by neural crest generating connective tissue components
- cartilage, bone, ligaments
- arises from midbrain and hindbrain region
Arch Features
Each arch contains: artery, cartilage, nerve, muscular component
Arches and Phanynx Form the face, tongue, lips, jaws, palate, pharynx and neck cranial nerves, sense organ components, glands
- Humans have 5 arches - 1, 2, 3, 4, 6 (Arch 5 does not form or regresses rapidly)
- from in rostro-caudal sequence, Arch 1 to 6 from week 4 onwards
- arch 1 and 2 appear at time of closure of cranial neuropore
- Face - mainly arch 1 and 2
- Neck components - arch 3 and 4 (arch 4 and 6 fuse)
Arch Features
- arch
- groove
- externally separates each arch
- also called a cleft
- only first pair persist as external auditory meatus
- externally separates each arch
- pouch
- internally separates each arch
- pockets from the pharynx
- membrane
- ectoderm and endoderm contact regions
- only first pair persist as tympanic membrane
- Pharyngeal Arch 1 (Mandibular Arch) has 2 prominances
- smaller upper- maxillary forms maxilla, zygomatic bone and squamous part of temporal
- larger lower- mandibular, forms mandible
- Pharyngeal Arch 2 (Hyoid Arch)
- forms most of hyoid bone
- Arch 3 and 4
- neck structures
Arch Arteries
placental vein -> liver -> heart -> truncus arteriosus -> aortic sac -> arch arteries -> dorsal aorta -> placental artery |
Human embryo (5mm, lateral view) showing pulmonary arteries |
Arch 5 Artery? |
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There has been ongoing controversy as to whether the fifth arch artery, that forms in fish, ever develops in birds and mammals. A recent study in mouse and human embryos identified the presence of an extra vessel presence in a single Carnegie Stage 14 human embryo.[5] |
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Arch Cartilage
- Arch 1 - Meckel's cartilage, horseshoe shaped
- dorsal ends form malleus and incus
- midpart forms ligaments (ant. malleus, sphenomandibular)
- ventral part forms mandible template
- Arch 2 - Reichert's cartilage
- dorsal ends form stapes and Temporal bone styloid process
- ventral part ossifies to form hyoid bone components
- lesser cornu and superior body
- Arch 3- forms greater cornu and inferior part of hyoid
- Arch 4&6- form laryngeal cartilages, except epiglottis (from hypobranchial eminence)
Arch Muscle
- Arch 1 - muscles of mastication, mylohyoid, tensor tympanic, ant. belly digastric
- Arch 2 - muscles of facial expression, stapedius, stylohyoid, post. belly digastric
- Arch 3 - stylopharyngeus
- Arch 4&6 - crycothyroid, pharynx constrictors, larynx muscles, oesophagus (st. muscle)
Head and Heart Muscle[6] On the left side of the body (right part of figure) the facial expression muscles have been removed to show the masticatory muscles.
Arch Nerve
- Arch 1 - CN V trigeminal, caudal 2/3 maxillary and mandibular, cranial 1/3 sensory nerve of head and neck, mastication motor
- Arch 2 - CN VII facial
- Arch 3 - CN IX glossopharyngeal
- Arch 4&6 - CN X vagus, arch 4- superior laryngeal, arch 6- recurrent laryngeal
Arch Pouches
- Arch 1 - elongates to form tubotympanic recess, tympanic cavity, mastoid antrum, eustachian tube
- Arch 2 - forms tonsillar sinus, mostly oblierated by palatine tonsil
- Arch 3 - forms inferior parathyroid and thymus
- Arch 4 - forms superior parathyroid, parafollicular cells of Thyroid
Thyroid Gland
- not a pouch structure
- first endocrine organ to develop day 24
- from floor of pharynx
- descends thyroglossal duct (which closes)
- upper end at foramen cecum
Anterior Pituitary
- not a pouch structure
- boundary epitheilal ectoderm in the roof of the pharynx
- forms a pocket (Rathke's pouch) that comes into contact with the ectoderm of developing brain.
- Rathke's pouch is named after German embryologist and anatomist Martin Heinrich Rathke (1793 — 1860).
Face Development
Begins week 4 centered around stomodeum, external depression at oral membrane
5 initial primordia from neural crest mesenchyme
- single frontonasal prominence (FNP) - forms forehead, nose dorsum and apex
- nasal placodes develop later bilateral, pushed medially
- paired maxillary prominences - form upper cheek and upper lip
- paired mandibular prominences - lower cheek, chin and lower lip
Frontonasal Process
The frontonasal process (FNP) forms the majority of the superior part of the early face primordia. It later fuses with the maxillary component of the first pharyngeal arch to form the upper jaw. Failure of this fusion event during the embryonic period leads to cleft lip. Under the surface ectoderm the process mesenchyme consists of two cell populations; neural crest cells, forming the connective tissues; and the mesoderm forming the endothelium of the vascular network.
A chicken developmental model study has identified a specific surface region, the Frontonasal Ectodermal Zone (FEZ), initially induced by bone morphogenetic proteins that appears to regulate the future growth and patterning of the frontonasal process. The specific frontonasal ectodermal zone was located in the frontonasal process ectoderm flanking a boundary between Sonic hedgehog (Shh) and Fibroblast growth factor 8 (Fgf8) expression domains.[7]
Head/Skull
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Sensory Placodes
- During week 4 a series of thickened surface ectodermal patches form in pairs rostro-caudally in the head region.
- Recent research suggests that all sensory placodes may arise from common panplacodal primordium origin around the neural plate, and then differentiate to eventually have different developmental fates.
- These sensory placodes will later contribute key components of each of our special senses (vision, hearing and smell). Other species have a number of additional placodes which form other sensory structures (fish, lateral line receptor). Note that their initial postion on the developing head is significantly different to their final position in the future sensory system
Otic placode
in the stage 13/14 embryo (shown below) the otic placode has sunk from the surface ectoderm to form a hollow epithelial ball, the otocyst, which now lies beneath the surface surrounded by mesenchyme (mesoderm). The epithelia of this ball varies in thickness and has begun to distort, it will eventually form the inner ear membranous labyrinth.
Lens placode
lies on the surface, adjacent to the outpocketing of the nervous system (which will for the retina) and will form the lens.
- Links: Lens Development
Nasal placode
has 2 components (medial and lateral) and will form the nose olfactory epithelium.
- Links: Smell Development | Placodes
Head Growth
- continues postnatally - fontanelle allow head distortion on birth and early growth
- bone plates remain unfused to allow growth, puberty growth of face
Fetal head growth (circumference)
Skull Overview
Chondrocranium - formed from paraxial mesoderm
- cranial end of vertebral column
- modified vertebral elements
- occipital and cervical sclerotome
- bone preformed in cartilage (endochondrial ossification)
Cranial Vault and Facial Skeleton - formed from neural crest
- muscle is paraxial mesoderm
- somitomeres and occipital somites
Calveria - bone has no cartilage (direct ossification of mesenchyme)
- bones do not fuse, fibrous sutures 1. allow distortion to pass through birth canal 2. allow growth of the brain
- 6 fontanelles, posterior closes at 3 months, anterior closes at 18 months
- Links: Skull Development
Palate
The palate has two key stages of development during embryonic and an early fetal involving the fusion of structures (epithelia to mesenchymal).
Embryonic
Primary palate, fusion in the human embryo between stage 17 and 18, from an epithelial seam to the mesenchymal bridge.
Fetal
Secondary palate, fusion in the human embryo in week 9. This requires the early palatal shelves growth, elevation and fusion during the early embryonic period. The fusion event is to both each other and the primary palate. palatal shelf elevation | secondary palate
- Links: palate
Ear Auricles
- form from 6 hillocks (week 5)
- 3 on each of arch 1 and 2
Tongue Development
- Ectoderm of the first arch surrounding the stomodeum forms the epithelium lining the buccal cavity.
- Also the salivary glands, enamel of the teeth, epithelium of the body of the tongue.
- As the tongue develops "inside" the floor of the oral cavity, it is not readily visible in the external views of the embryonic (Carnegie) stages of development.
- Contributions from all arches, which changes with time
- begins as swelling rostral to foramen cecum, median tongue bud
- Arch 1 - oral part of tongue (ant 3/2)
- Arch 2 - initial contribution to surface is lost
- Arch 3 - pharyngeal part of tongue (post 1/3)
- Arch 4 - epiglottis and adjacent regions
Tongue muscle
- Tongue muscles originate from the somites.
- Tongue muscles develop before masticatory muscles and is completed by birth.
- Masticatory muscles originate from the somitomeres.
- These muscles develop late and are not complete even at birth.
Salivary Glands
- epithelial buds in oral cavity (week 6 to 7) extend into mesenchyme
- parotid, submandibular, sublingual
Pharyngeal Arch Tables
Pharyngeal Arch | Nerve | Artery | Neural Crest (Skeletal Structures) |
Muscles | Ligaments |
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1 (maxillary/mandibular) |
trigeminal (CN V) | maxillary artery (terminal branches) | mandible, maxilla, malleus, incus | muscles of mastication, mylohyoid, tensor tympanic, ant. belly digastric | ant lig of malleus, sphenomandibular ligament |
2 (hyoid) |
facial (CN VII) | stapedial (embryonic) corticotympanic (adult) |
stapes, styloid process, lesser cornu of hyoid, upper part of body of hyoid bone | muscles of facial expression, stapedius, stylohyoid, post. belly digastric | stylohyoid ligament |
3 | glossopharyngeal (CN IX) | common carotid, internal carotid arteries | greater cornu of hyoid, lower part of body of hyoid bone | stylopharyngeus | |
4 | vagus (CN X) superior laryngeal branch | part of aortic arch (left), part right subclavian artery (right) | thyroid, cricoid, arytenoid, corniculate and cuneform cartilages | crycothyroid, soft palate levator veli palatini (not tensor veli palatini) | |
6 | vagus (CN X) recurrent laryngeal branch | part of left pulmonary artery (left), part of right pulmonary artery (right) | thyroid, cricoid, arytenoid, corniculate and cuneform cartilages | larynx intrinsic muscles (not cricothyroid muscle) |
Structures derived from Pouches
Each pouch is lined with endoderm and generates specific structures.
Overall Structure | Specific Structures | |
tubotympanic recess | tympanic membrane, tympanic cavity, mastoid antrum, auditory tube | |
intratonsillar cleft | crypts of palatine tonsil, lymphatic nodules of palatine tonsil | |
inferior parathyroid gland, thymus gland | ||
superior parathyroid gland, ultimobranchial body | ||
becomes part of 4th pouch |
Structures derived from Grooves
Only the first groove differentiates into an adult structure and forms part of the external acoustic meatus.
Structures derived from Membranes
At the bottom of each groove lies the membrane which is formed from the contact region of ectodermal groove and endodermal pouch. Only the first membrane differentiates into an adult structure and forms the tympanic membrane.
Movies
There are a number of movies representing development of different features of the head and face.
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- Links: Head and Face Movies | Movies
References
- ↑ Nagarajan M, Sharbidre KG, Bhabad SH & Byrd SE. (2018). MR Imaging of the Fetal Face: Comprehensive Review. Radiographics , , 170142. PMID: 29652578 DOI.
- ↑ Li W, Xu H, Zhao L & Li X. (2018). Branchial anomalies in children: A report of 105 surgical cases. Int. J. Pediatr. Otorhinolaryngol. , 104, 14-18. PMID: 29287855 DOI.
- ↑ Graham A & Richardson J. (2012). Developmental and evolutionary origins of the pharyngeal apparatus. Evodevo , 3, 24. PMID: 23020903 DOI.
- ↑ Talbot JC, Johnson SL & Kimmel CB. (2010). hand2 and Dlx genes specify dorsal, intermediate and ventral domains within zebrafish pharyngeal arches. Development , 137, 2507-17. PMID: 20573696 DOI.
- ↑ Bamforth SD, Chaudhry B, Bennett M, Wilson R, Mohun TJ, Van Mierop LH, Henderson DJ & Anderson RH. (2013). Clarification of the identity of the mammalian fifth pharyngeal arch artery. Clin Anat , 26, 173-82. PMID: 22623372 DOI.
- ↑ Diogo R, Kelly RG, Christiaen L, Levine M, Ziermann JM, Molnar JL, Noden DM & Tzahor E. (2015). A new heart for a new head in vertebrate cardiopharyngeal evolution. Nature , 520, 466-73. PMID: 25903628 DOI.
- ↑ Foppiano S, Hu D & Marcucio RS. (2007). Signaling by bone morphogenetic proteins directs formation of an ectodermal signaling center that regulates craniofacial development. Dev. Biol. , 312, 103-14. PMID: 18028903 DOI.
Reviews
Gupta P, Tripathi T, Singh N, Bhutiani N, Rai P & Gopal R. (2020). A review of genetics of nasal development and morphological variation. J Family Med Prim Care , 9, 1825-1833. PMID: 32670926 DOI.
Nagarajan M, Sharbidre KG, Bhabad SH & Byrd SE. (2018). MR Imaging of the Fetal Face: Comprehensive Review. Radiographics , , 170142. PMID: 29652578 DOI.
Abramyan J & Richman JM. (2018). Craniofacial development: discoveries made in the chicken embryo. Int. J. Dev. Biol. , 62, 97-107. PMID: 29616744 DOI.
Adameyko I & Fried K. (2016). The Nervous System Orchestrates and Integrates Craniofacial Development: A Review. Front Physiol , 7, 49. PMID: 26924989 DOI.
Kuratani S & Schilling T. (2008). Head segmentation in vertebrates. Integr. Comp. Biol. , 48, 604-10. PMID: 20607135 DOI.
Grevellec A & Tucker AS. (2010). The pharyngeal pouches and clefts: Development, evolution, structure and derivatives. Semin. Cell Dev. Biol. , 21, 325-32. PMID: 20144910 DOI.
Articles
Choe CP & Crump JG. (2015). Dynamic epithelia of the developing vertebrate face. Curr. Opin. Genet. Dev. , 32, 66-72. PMID: 25748249 DOI.
Shone V & Graham A. (2014). Endodermal/ectodermal interfaces during pharyngeal segmentation in vertebrates. J. Anat. , 225, 479-91. PMID: 25201771 DOI.
Thi Thu HN, Haw Tien SF, Loh SL, Bok Yan JS & Korzh V. (2013). Tbx2a is required for specification of endodermal pouches during development of the pharyngeal arches. PLoS ONE , 8, e77171. PMID: 24130849 DOI.
Search PubMed
Search term: Head Development | Pharyngeal Arch Development | | Face Development
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Books
Hinrichsen K. The early development of morphology and patterns of the face in the human embryo. Berlin ; New York : Springer-Verlag, c1985
Additional Images
Historic
Historic Disclaimer - information about historic embryology pages |
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Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding. (More? Embryology History | Historic Embryology Papers) |
Development of the Pharynx and Neck
Terms
Head Terms (expand to view) |
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Other Terms Lists |
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Terms Lists: ART | Birth | Bone | Cardiovascular | Cell Division | Endocrine | Gastrointestinal | Genital | Genetic | Head | Hearing | Heart | Immune | Integumentary | Neonatal | Neural | Oocyte | Palate | Placenta | Radiation | Renal | Respiratory | Spermatozoa | Statistics | Tooth | Ultrasound | Vision | Historic | Drugs | Glossary |
Palate Development (expand to see terms) |
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Terms Lists: ART | Birth | Bone | Cardiovascular | Cell Division | Endocrine | Gastrointestinal | Genital | Genetic | Head | Hearing | Heart | Immune | Integumentary | Neonatal | Neural | Oocyte | Palate | Placenta | Radiation | Renal | Respiratory | Spermatozoa | Statistics | Tooth | Ultrasound | Vision | Historic | Drugs | Glossary |
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- Essentials of Facial Growth Enlow and Hans
Cite this page: Hill, M.A. (2024, June 15) Embryology Head Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Head_Development
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G