DEVELOPMENT OF HEAD AND NECK - Univerzita Karlovaanatomie.lf3.cuni.cz/centralni_prezentace/Traveni_Vyvoj_hlavy_a... · –right proximally: arteria pulmonalis dextra –right distally:

DEVELOPMENT OF HEAD AND NECK

© David Kachlík 30.9.2015

Vývoj hlavy, krku

pharyngeal

arches

Carnegie 13 (28 – 32 days)

4 – 6 mm, 30 somites


• lips

• oral cavity

– oral vestibule

• teeth

• tongue

• hard palate

• soft palate

• pharynx

• larynx


• parotid gland

• submandibular

gland

• sublingual

gland


• thyroid gland

• parathyroid gland

– 4 bodies

• thymus

http://www.mayoclinic.com/images/image_popup/pthyroid.jpg


Development of the digestive tube

• primitive gut • formed during the 4th week, as the head, tail and

lateral folds incorporate a part of the yolk sack into

the embryo

– foregut (preentereon) – separated from

stomodeum (primitive mouth) by membrana

oropharyngea, protrusion of base of lower

respiratory tract

– midgut (mesenteron) – aborally from liver bud

to Cannon-Böhm point

– hindgut (metenteron) – further, separated from

proctodeum (anal pit) by membrana cloacalis© David Kachlík 30.9.2015

Origin of mesenchyme

• paraaxial mesoderm (non-segmented)– bones of skull base and some of bones of calvaria

– all skeletal muscles

– dermis and fibrous tissue on the dorsal part of head

• ectomesenchyme (from the neural crest)– skeleton of face and pharyngeal arches

• ectodermal placodes (thickened areas of ectoderm)

• pharyngeal arches

• occipital segments (basis et condyli ossis occipitalis)


Pharyngeal apparatus• pharyngeal arches (arcus pharyngei)

• pharyngeal pouches (sacci pharyngei)

• pharyngeal grooves (sulci pharyngei)

• pharyngeal membranes (membranae

pharyngeae)

Thomas W. Sadler, Langman´ Medical embryology, 10th edition


Pharyngeal arches (arcus pharyngei)

• paired structures

• begin to develop in the 4th – 5th week

• separation of columns of mesenchyme:

– pharyngeal grooves on external side

(depressions in ectoderm)

–pharyngeal pouches on internal side

(formed by endoderm of primitive larynx)

–grooves and pouches never merge (no gills

form)© David Kachlík 30.9.2015

Pharyngeal arches (arcus pharyngei)

• mesenchyme of neural crest cells is

streaked by para-axial mesoderm and in

each pharyngeal arch gives rise to

muscles

• cartilages and skeleton of arches are

differentiated from ectomesenchyme

• each arch is innervated by a cranial nerve

and has its own artery (aa. arcuum

pharyngeorum = aortic arches)

• 5th arch does not arise© David Kachlík 30.9.2015


Aortic arches

(Aa. arcuum pharyngeorum)


Derivatives of aortic arches

• 1st pair – arteria maxillaris + a. carotis externa

• 2nd pair – arteria stapedia

• 3rd pair – proximally - arteria carotis communis

– distally - arteria carotis interna



• 4th pair

– left – part of arcus aortae

– right – arteria subclavia dx.

• distal part of a. subclavia dx. arises from aorta dorsalis dextra

– a. subclavia sin. is not derived from aortic arch but

from the 7th intersegmental artery



• 5th pair – Ø

• 6th pair

– left proximally: arteria pulmonalis sinistra

– left distally: ductus arteriosus (Botali)

– right proximally: arteria pulmonalis dextra

– right distally: Ø




arch nerve muscles skeletal structures ligaments arteries

1. mandibular

(maxillary

and

mandibular

process)

n. trigeminus muscles of mastication

(m. temporalis, m.

masseter, m.

pterygoideus medialis et

lateralis)

m. mylohyoideus, venter

anterior m. digastrici

m. tensor tympani

m. tensor veli palatini

premaxilla, maxilla, os

palatinum, os

zygomaticum, squama

ossis temporalis,

Meckel´s cartilage,

mandibula, malleus,

incus

lig. mallei ant.,

lig.

sphenomandibulare

a. maxillaris

2. hyoid n. facialis muscles of facial

expression

(m. buccinator, mm.

auriculares, m. frontalis,

platyzma, m. orbicularis

oris et oculi)

m. stapedius

m. stylohyoideus, venter

posterior m. digastrici

stapes,

processus styloideus,

cornua minora et

corpus ossis hyoidis

(upper part)

lig. stylohyoideum a. stapedia

3. arch n.glossopharyngeus m. stylopharyngeus cornua majora et

corpus ossis hyoidis

(lower part)

a. carotis communis

a. carotis interna

(proximal part of pars

cervicalis)

4. left n. laryngeus superior

(n.X)

m. cricothyroideus, m.

levator veli palatini, m.

constrictor pharyngis

med. et inf.,

intrinsic muscles of

larynx

striated muscles of the

oesophagus

5th arch is missing

cartilaginous parts of the

4th and 6th arch merge

into a common base of

the cartilages of the

larynx

cartilago thyroidea,

cricoidea, arytenoidea,

corniculata,

cuneiformis

arcus ortae from a.

carotis communis sin. to

a. subclavia sin

right prox. part of a.subclavia dx.

6. left n. laryngeus recurrens

(fibres from n.

accessorius using n.

vagus)

a.pulmonalis sin., ductus

arteriosus

right a.pulmonalis dx.


First pharyngeal arch

(arcus pharyngeus primus)

• 2 processes

– maxillary (cranially)

– mandibular (caudally)

• contains the Meckel´s cartilage (gives rise to

malleus and incus)

• formation of the lower jaw

– merging of the right and left mandibular

process, subsequent membranous

ossification



Second pharyngeal arch

(arcus pharyngeus secundus)

• cartilage (= Reichert´s cartilage)

• by merging of right and left arch in the midline → part of body and lesser horns of hyoid bone are formed



Third pharyngeal arch

• cornua majora + caudal part of corpus ossis

hyoidei

• innervation: n. IX

Fourth pharyngeal arch

• merges with 6th arch

• cartilago cricoidea + thyroidea

• muscles of larynx, palate (apart from m.

tensor veli palatini), pharynx (apart from m.

stylopharyngeus)

• innervation: n. X (n. laryngeus sup.)© David Kachlík 30.9.2015

Fifth pharyngeal arch

• does not arise in human at all

• merges with 4th arch

• muscles of larynx

• innervation: n.X (n. laryngeus recurrens)

• containing fibres from n.XI

Sixth pharyngeal arch


Pharyngeal pouches (sacci pharyngei)

• human embryo has 5 pouches

• their endoderm gives rise to branchiogenic

organs



First pharyngeal pouch

• recessus tubotympanicus (tubotympanic

recess)

– blind recess (toward 1st pharyngeal groove)

• its end is widened into primitive tympanic

cavity

• medial part remains straight → tuba

auditiva Eustachii

• together with 1st pharyngeal groove it

participates in formation of eardrum

(membrana tympanica)© David Kachlík 30.9.2015

Second pharyngeal pouch

• base of palatine tonsil (tonsilla palatina)

• fossa supratonsillaris

http://biology.clc.uc.edu/fankhauser/labs/microbiology/strep_detection/strep_test.htm


Third pharyngeal pouch

• dorsal part

– inferior parathyroid bud

• ventral part

– thymic bud

• bases migrate caudally



Fourth pharyngeal pouch

• dorsal part

– superior parathyroid bud

• ventral part

– rudimentary

– ultimopharyngeal body (corpus

ultimopharyngeum / ultimobranchialis)

• cells from neural crest

• differentiate into parafolicular (C-cells) of thyroid

gland (producing calcitonin)


Pharyngeal grooves (Sulci pharyngei)

• 4 pairs of grooves are formed within 5th week

• dorsal part of 1st groove persists as external acoustic meatus (meatus acusticus externus)

– epithelium on floor formes outer surface of eardrum (membrana tympanica)

• other grooves come to lie in a depression cervical sinus (sinus cervicalis)

• sinus cervicalis is obliterated as the neck develops, lateral cervical cysts may persist fistulae © David Kachlík 30.9.2015

Lateral cervical fistula

http://www.ultratwistersgym.com/Resources/Head/Head%20and%20Neck.htmlhttp://journals.tums.ac.ir/full_text.aspx?org_id=59&culture_var=en&journal_id=4&issue_id=1293&manuscript_id=11415&segment=en


Innervation of tongue

• n. V3 –n. lingualis

• n. VII – chorda tympani

• n. IX

• n. X


Development of tongue• 4th week: primordia lingualia appear on inner side of

pharyngeal pouches

• 1st arch: tuberculum impar (fades out) + 2 tubercula lingualia lateralia apex + dorsum linguae (n.V3)

• 2nd arch: copula (wears off) – n.VII – chorda tympani (taste)

• 3rd-4th arch: eminentia hypopharyngea radix linguae (n.IX, n.X)– sulcus terminalis (separates the body and the root of the

tongue)

• 4th arch epiglottis (n. X)

• muscles:– from myotomes of occipital somites (n. XII)

– from 4th pharyngeal arch (n. X – only m. palatoglossus)© David Kachlík 30.9.2015

Development of tongue



Congenital defects of tongue

• cysts and fistulae – remnants of the

thyroglossal duct

• ankyloglossia (t= ongue-tie)

– short frenulum linguae

• macroglossia

• microglossia

• glossoschissis (= cleft tongue)

– rare, incomplete cleft


Ankyloglossia

http://www.ghorayeb.com/TongueTie.html


Macroglossia - Microglossia

http://www.consultantlive.com/display/article/10162/43839 http://dentallecnotes.blogspot.cz/2011/08/developmental-disturbances-of-tongue.html


Development of the thyroid gland

• growth of epithelium between tuberculum impar and copula → location of foramen caecum

• growths in front of pharynx in a caudal direction

• within the descent is connected to tongue by means of ductus thyroglossus

• progressive descent in front of hyoid bone and cartilages of larynx

• within 7th week gets to its final place in front of trachea

• gets functional at the end of 3rd month© David Kachlík 30.9.2015

Congenital defects of thyroid gland

• thyroglossal duct cysts

– may develop anywhere along the course of

descent of thyroid gland from the tongue

• thyroglossal duct fistulae

– communication of cysts with external space

• ectopic thyroid gland

– along the course of descent

– most often at root of tongue

– this tissue may be functional© David Kachlík 30.9.2015

Thyroglossal duct cysts

http://www.learningradiology.com/archives06/COW%20231-Thyroglossal%20Duct%20Cyst/tgdccorrect.html

http://www.surgical-tutor.org.uk/default-home.htm?tutorials/thyroglossal.htm~right


Processus pyramidalis

glandulae thyroideae

• the most common congenital defect

• along the course of the descent

• 40 %

http://www.anatomyatlases.org/AnatomicVariants/OrganSystem/Images/82.shtml


DiGeorge syndrome

Aplasia thymoparathyroideamicrodeletion 22q11.2

1:3000


Development of face

facial primordia appear at end of 4th week (neural crest

ectomesenchyme of 1st pharyngeal arch) around

stomodeum

• frontonasal prominence cranially

• maxillary prominences laterally

• mandibular prominences caudally

– on each side develop bilateral oval thickenings of

the surface ectoderm nasal placodes

• they depress within 5th week nasal pits

• pits are bordered by horseshoe-shaped

elevations = medial and lateral nasal

prominences © David Kachlík 30.9.2015

Development of face



Development of face• maxillary prominences enlarge (cheeks and upper

jaw) and growth medially

• pressing medial nasal prominences to the midline

→ then they merge

• upper lip is formed by the maxillary prominences

and medial nasal prominences

• lower lip and jaw are formed by mandibular

prominences that merge in the midline

• nose arises from 5 sources:

– frontonasal prominence, 2 medial nasal

prominences, 2 lateral nasal prominences© David Kachlík 30.9.2015

Development of

oral and nasal cavity

stomodeum

• a pit lined with ectoderm

boundaries:

• lower processes of 1st pharyngeal arch – mandibula

• on sides upper processes of 1st pharyngeal arch –maxilla

• frontonasal prominence with nasal placodes from above ( pits, vesicles, open into the primitive oral cavity), medial and lateral nasal prominences

• membrana oropharyngea (buccopharyngea) breaks up on 26th day


Development of palate

• primary palate– from intermaxillary segment

• by merging of both medial nasal prominences)

– lip component philtrum

– component for the upper jaw (carries 4 incisors)

– palatine component (forms the primary palate)

– passes continuously into nasal septum (from frontonasal prominence)

• secondary palate– by merging of palatine processes of maxillary

process (6th week)

– ventrally fusion with primary palate (future os incisivum) © David Kachlík 30.9.2015

Development of palate



Separation of oral and nasal cavity



Cleft malformations of face and palate

• impaired fusion of structures (1:550)

• anterior palate clefts (cheiloschisis, cheilognathoschisis)

– lateral lip, upper jaw cleft, cleft between the primary and secondary palates

–partial or complete lack of fusion of maxillary prominence with medial nasal prominence on one or both sides

• posterior palate clefts (palatoschisis)

–secondary palate cleft, uvula cleft



• combination of clefts lying anterior as well as posterior to incisive foramen (cheilo-gnatho-palatoschisis)

• oblique facial clefts

– failure in merging of maxillary prominence with its corresponding lateral nasal prominence

• median (midline) lip cleft

– rare abnormality

– incomplete merging of two medial nasal prominences in the midline



http://www.craniofacial.net/cleft-lip-cleft-palate-only

http://blog.johnrchildress.com/2011/06/07/real-leadership-and-hope/




http://www.rodina.cz/clanek3188.htm

beforebefore

afterafter


Development of salivary glands

• epithelial pouches of oral cavity (6th – 8th

week)

• intergrowth into adjacent ectomesenchyme

its connective tissue comes from neural

crest

• parenchyme ( secretion) comes from

proliferating oral epithelium

– ectoderm gl. parotidea

– endoderm gl. submandibularis et sublingualis © David Kachlík 30.9.2015

Development of teeth6th week: proliferation of oral epithelium

(ectoderm) into surrounding

ectomesenchyme

• dental lamina (parallell to labiogingival crest)

• ectoderm → enamel organ

– outer enamel epithelium

– stratum intermedium, stellate reticulum

– inner enamel epithelium (ameloblasts)

• ectomesenchyme → dental papilla

(odontoblasts)© David Kachlík 30.9.2015

Development of teeth• production of dentine

– odontoblasts: procollagen → predentin → dentin• with thickening of dentine layer, odontoblasts retreat into the

dental papilla, leaving a thin cytoplasmic processes (dental processes or Tomes fibres)

• production of enamel– basal surface of ameloblasts becomes secretory:

• enamel matrix (organic – mineralisation)

• development of roots• dental epithelial layers penetrate into the underlying

mesenchyme root sheath

• mesenchymal cells on the outside of tooth and in contact with dentin of root differentiate into cementoblasts

• permanent teeth• secondary dental lamina is located lingually to primary one


Development of teeth





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DEVELOPMENT OF HEAD AND NECK - Univerzita Karlovaanatomie.lf3.cuni.cz/centralni_prezentace/Traveni_Vyvoj_hlavy_a... · –right proximally: arteria pulmonalis dextra –right distally: