2009 BGD-B Lecture Face and Ear

Links: [../../Notes/head.htm Systems Notes - Head and Neck] | [../../Notes/ear.htm Systems Notes - Hearing] [../../Sections/anat2300/2004/ANAT2300L09.htm Lecture Slides (2004) ANAT2300 Head Development] | [../../Sections/anam1006/2003/ANAM1006L7.htm Lecture Slides (2003) ANAM1006 Head Development]

1. Lecture Overview

== Face and Neck == Pharyngeal Arches origins components structures formed Pharynx Ear Development origins otic placode external, middle, inner ear Abnormalities

Links: [../../Notes/head.htm Systems Notes - Head and Neck]

2. Human Embryo Comparison

More: Note the great change beween the middle of embryological development to the end.

Links: [../../wwwhuman/Stages/Stages.htm Embryo Stages] | [../../wwwhuman/Stages/Images/stage14compare23.jpg Stage Comparison] | [../../wwwhuman/Stages/Stage14L.htm Stage 14] | [../../wwwhuman/Stages/Stage23L.htm Stage 23]

3. Human Embryo External Appearance

File:600stage14.jpg	File:600stage23.jpg
== Stage 14 ==	== Stage 23 ==

More: Externally the pharyngeal arches are initially the most obvious external feature. Sensory placodes are present on the surface (but not obvious). By stage 14 the sensory placode that contributes to hearing (otic placode) has already been lots from the surface and now lies in the mesenchyme in the neck region. The cervical sinus is a surface landmark shwing the region where arch 2 is growing down over the

Links: [../../wwwhuman/Stages/Stages.htm Embryo Stages] | [../../wwwhuman/Stages/Images/stage14compare23.jpg Stage Comparison] | [../../wwwhuman/Stages/Stage14L.htm Stage 14] | [../../wwwhuman/Stages/Stage23L.htm Stage 23]

4. Pharynx

== common forgut cavity == begins at buccopharyngeal membrane "arched" beneath the brain over the pharyngeal eminence changes orientation as descends	File:Head arches.jpg
	File:Pb2.gif

 

7. Pharyngeal Arch Components

== each arch has initially similar components == contributions from all 3 germ layers Ectoderm - outside surface and Neural Crest of core Mesoderm - core of mesenchyme Endoderm - inside pharyngeal surface

File:Head1.gif

File:Head1.gif  

10. Pharyngeal Arch Neural Crest

== Cranial neural crest (midbrain and hindbrain region) enters pharyngeal arch mesenchyme == Forms connective tissues (cartilage, bone, ligaments): jaw cartilage and bone middle ear in mammals frontonasal process bones teeth dentine cranial nerve peripheral neurons and glia

File:Head arches.jpgFile:Ba2qt2.gif

More: The cranial neural crest therefore contributes much of the underlying structure of the face. Rhombomeres are the transient segmentation of the hindbrain.

Links: [../../Notes/ncrest.htm Neural Crest Notes] |

11. Pharyngeal Arch Core

== Each arch contains == artery cartilage nerve muscular component

File:Archcartilage.jpg

File:Meckelsm.jpg

More:

Links: Sadler Image Bank - Pharyngeal Arches | Sadler Image Bank - Pharyngeal Arch Arteries | Embryo Images - Aortic Arch Vessels |

12. Pharyngeal Arch 1

== Mandibular Arch == has 2 prominances upper - smaller, maxillary forms maxilla, zygomatic bone and squamous part of temporal lower - larger, mandibular mandible	File:Pb2.gifFile:Mandible sm.jpg

More:

Links: Embryo Stage 12 | Embryo Stage 13 | Embryo Images - Pharyngeal Arch 1 and 2 early | [%20http://www.med.unc.edu/embryo_images/unit-hednk/hednk_htms/hednk011.htm Embryo Images - Pharyngeal Arch 1 and 2 later] | Dev Biol - Jaw structure in the fish, reptile, and mammal |

13. Pharyngeal Arch 2 - 4

== Pharyngeal Arch 2 == Hyoid Arch forms most of hyoid bone 5 segments: body, two greater cornua, two lesser cornua Arch 3 and 4 neck structures hyoid bone, thyroid and cricoid cartilages	File:Archcartilage sm.jpgFile:Hyoid bone sm.jpg

More: Hyoid bone ossified from six centres (2 body, 1 for each cornu). Ossiification - late fetal in the greater cornua, then in the body, then postnatally (1-2 years) in the lesser cornua.

Links: Embryo Stage 13 |

14. Pharyngeal Arch Derivatives

Structures derived from Arches

== Arch ==	== Nerve ==	== Muscles ==	== Skeletal ==	== Artery ==
1 (maxillary/mandibular)	trigeminal (V)	mastication (temporalis, masseter, medial pterygoid, lateral pterygoid)	mandible model malleus, incus Meckel's cartilage	maxillary (terminal branches)
2 (hyoid)	facial (VII)	facial expression ( buccinator, platysma, stapedius, stylohyoid, digastric posterior belly)	stapes, styloid process, lesser cornu of hyoid, upper part of body of hyoid bone Reichert's cartilage	stapedial (embryonic) corticotympanic (adult)
3	glossopharyngeal (IX)	Stylopharyngeus	greater cornu of hyoid, lower part of body of hyoid bone	common carotid, internal carotid (root)
4 and 6	superior laryngeal and recurrent laryngeal branch of vagus (X)	intrinsic muscles of larynx, pharynx; levator palati	thyroid, cricoid, arytenoid, corniculate and cuneform cartilages	4 - aortic arch, right subclavian 6 - ductus arteriosus, pulmonary (roots)

Structures derived from Pouches

== POUCH ==	== Overall Structure ==	== Specific Structures ==
1	tubotympanic recess	tympanic membrane, tympanic cavity, mastoid antrum, auditory tube
2	intratonsillar cleft	crypts of palatine tonsil, lymphatic nodules of palatine tonsil
3	inferior parathyroid gland, thymus gland
4	superior parathyroid gland, ultimobranchial body
5	becomes part of 4th pouch

Membranes- 1st membrane forms the tympanic membrane

More: The above table is not for you to learn by heart but an indication of the structures formed from each arch.

It is easy to remember that:

1st arch - about the mouth (chewing, jaw) and the external and middle ear.

2nd arch - about the face, hyoid and external and middle ear.

3rd arch - about the neck and endocrine.

4th arch- about the neck and endocrine.

Links: [../../Notes/head.htm#fate Arch Derivatives] | Dev Biol - Some derivatives of the pharyngeal arches |

15. Pharyngeal Abnormalities

Vestiges - cartilaginous or bony developmental remnants under skin on side of neck

More:

Links: [../../Notes/head2.htm Head and Neck Abnormalities] | [../../Notes/ear2.htm Hearing Abnormalities] | [../../Defect/page5a.htm Abnormal Development - Fetal Alcohol Syndrome] | [../../Movies/usoundab/Cleft1.htm Abnormal Ultrasound - Cleft Lip] |

16. Face

Face develops from week 4 to 10.

File:Face16to18.jpg	File:Face16to18.gif
== 1 Frontonasal prominence - Nasal (medial, lateral) == 2 Maxillary2 Mandibular	Face Development cartoon

More:

Links: [../../Notes/face.htm Face Development] | Sadler Image Bank - Frontal aspect of the face 5 week and 6 week embryo | Sadler Image Bank - Frontal aspect of the face 7 week embryo |

17. Palate

File:Cleft1label.jpg	File:Cleft2label.jpg
[../../Movies/usoundab/Cleft1.htm Ultrasound Movie - Facial Cleft 1 ]	[../../Movies/usoundab/Cleft2.htm Ultrasound Movie - Facial Cleft 2 ]

More: Cleft lip and palate develop between the 4th and 8th week of gestation and is dominated by changes resulting in the formation of the nose. Palatal development occurs between the 7th and 12th week of gestation and is divided into the formation of the primary palate (prolabium), premaxilla and cartilaginous septum) and formation of the secondary palate (hard and soft palate). The animation above shows the early fusion of the primary palate in the human embryo between stage 17 and 18, going from an epithelial seam to the mesenchymal bridge.

Links: [../../Notes/face6.htm Face Development - Primary Palate] | [../../Notes/face2.htm Face Development Abnormalities] | [../../Movies/usoundab/Cleft1.htm Abnormal Ultrasound - Cleft Lip] |

18. Tongue

== Derived from all pharyngeal arches contributing different components == Somites - tongue muscle cells Somitomeres - muscles of mastication

More: The tongue develops "inside" the floor of the oral cavity, therefre it is not readily visible in the external views of the embryonic (Carnegie) stages of development. Somitomeres are the unsegmented mesoderm found in the head region, in a similar location to that of somites in the body.

Links: [../../Notes/head6.htm Tongue Development] | [../../Notes/tongue.htm Sensory Development - Taste]

#. Movies

Movie of the human head covering the Carnegie stages from 15 to 22. Note the images are not to scale.

[../../Movies/CSthead.htm Quicktime movie 179 Kb] in new window.

Movie of the human head covering the Carnegie stages from 16 to 18.

Movie of stage 13/14 pig embryo sections showing the head region of the nasal placodes.

File:Face.jpg

[../../Movies/larsen/face.mov Face Development Overview] (300 Kb)

[../../Movies/larsen/fetus.mov Fetal Development Overview] (800 Kb)

[../../Movies/larsen/tongue.mov Development of the Tongue] (187Kb)

References

Textbooks

Human Embryology (3rd ed.) Larson Chapter 12 pp 351-378

The Developing Human: Clinically Oriented Embryology (6th ed.) Moore and Persaud Chapter 10 pp 201- 240

Online Textbooks

Developmental Biology (6th ed.) Gilbert, Scott F. Sunderland (MA): Sinauer Associates, Inc.; c2000. : Cranial neural crest cell migration in the mammalian head | Regions of the neural crest | Jaw structure in the fish, reptile, and mammal | Some derivatives of the pharyngeal arches |

Eurekah Bioscience Collection Chapters taken from the Eurekah Bioscience database. Eurekah.com and Landes Bioscience; 2003. : Cranial Neural Crest and Development of the Head Skeleton |

Clinical Methods (3rd ed.) Walker, H.K.; Hall, W.D.; Hurst, J.W.; editors Stoneham (MA): Butterworth Publishers; c1990 : 63. Cranial Nerves IX and X: The Glossopharyngeal and Vagus Nerves | The Tongue |

Anatomy of the Human Body Gray, H. Philadelphia: Lea and Febiger, 1918.

Molecular Biology of the Cell (4th ed.) Alberts, Bruce; Johnson, Alexander; Lewis, Julian; Raff, Martin; Roberts, Keith; Walter, Peter New York and London: Garland Science; c2002.

Online Resources

Embryo Images Unit: Embryo Images Online | Craniofacial Development | Cell Populations | Pharyngeal Arches | Tongue | Nose and Upper Lip | Palate Development

Journals: GI Motility online (2006) Anatomy and development of oral cavity and pharynx| [NlmId&doptcmdl=Expanded&cmd=search The Cleft Palate Journal]

Terms

branchial arch (= pharyngeal arch) (Greek, branchia = gill) is a misnomer.

buccopharyngeal membrane (= oral membrane), apposition of ectoderm with endoderm with no mesoderm between. Lies at a ventral central depression (stomadeum). This external to internal junctionl region wiil break down, creating an opening and allows amniotic fluid to fill the foregut.

calveria

chondrocranium in humans, forms base of skull (in lower vertebrates encases brain).

cranial vault

facial skeleton

pharyngeal arch

pharynx

sensory placode

Glossary

[../../Notes/Index/A.htm A] | [../../Notes/Index/B.htm B] | [../../Notes/Index/C.htm C] | [../../Notes/Index/D.htm D] | [../../Notes/Index/E.htm E] | [../../Notes/Index/F.htm F] | [../../Notes/Index/G.htm G] | [../../Notes/Index/H.htm H] | [../../Notes/Index/I.htm I] | [../../Notes/Index/J.htm J] | [../../Notes/Index/K.htm K] | [../../Notes/Index/L.htm L] | [../../Notes/Index/M.htm M] | [../../Notes/Index/N.htm N] | [../../Notes/Index/O.htm O] | [../../Notes/Index/P.htm P] | [../../Notes/Index/Q.htm Q] | [../../Notes/Index/R.htm R] | [../../Notes/Index/S.htm S] | [../../Notes/Index/T.htm T] | [../../Notes/Index/U.htm U] | [../../Notes/Index/V.htm V] | [../../Notes/Index/W.htm W] |[../../Notes/Index/X.htm X] | [../../Notes/Index/Y.htm Y] | [../../Notes/Index/Z.htm Z]

WARNING

This material has been copied and communicated to you by or on behalf of the University of New South Wales pursuant to Part VB of the Copyright Act 1968 (the Act). The material in this communication may be subject to copyright under the Act. Any further copying or communication of this material by you may be the subject of copyright protection under the Act. Do not remove this notice.

© Dr M. A. Hill, 2007, Cell Biology Laboratory, School of Medical Sciences, Faculty of Medicine The University of New South Wales, Sydney, Australia.

UNSW Embryology ISBN: 978 0 7334 2609 4

UNSW CRICOS Provider Code No. 00098G[#copyright ]=== Slide Links === [#Intro Introduction][#1 1. Overview][#2 2. Embryo Comparison][#3 3. External Appearance][#4 4. Pharynx][#5 5. Pharyngeal Arches][#6 6. Early Arches][#7 7. Arch Components][#8 8. Arch Features][#9 9. Neck and Face][#10 10. Arch Neural Crest][#11 11. Arch Core][#12 12. Pharyngeal Arch 1][#13 13. Pharyngeal Arch 2-4][#14 14. Arch Derivatives][#14 15. Abnormalities][#15 16. Face][#17 17. Palate][#18 18. Tongue][#19 19. Ear][#References References][#Terms Terms][#Glossary Glossary]

File:Logo PoweredBy 25wht.gif