Difference between revisions of "ANAT2341 Lab 6 - Fetal"

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{{ANAT2341Lab6}}
 
{{ANAT2341Lab6}}
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==Fetal Growth==
 
==Fetal Growth==
 
{|
 
{|
|
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| <html5media height="480" width="400">File:fetal growth.mp4</html5media>
<Flowplayer height="320" width="285" autoplay="true">fetal growth.flv</Flowplayer><br>
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[[Quicktime Movie - Fetal Development|Quicktime]] | [[Movie - Fetal Development|Flash]]
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:'''Links:''' [[Fetal Development Movie]] | [[Media:fetal growth.mp4|MP4 version]] | [[Fetal Development]]  
 +
 
  
 
|
 
|
In this cartoon movie of fetal growth, observe the changing relative sizes of the head and body.
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In this cartoon movie of fetal growth, observe the changing relative sizes of the head, body and limbs.
  
  
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Finally consider fetal changes that are occurring in auditory pathway.
 
Finally consider fetal changes that are occurring in auditory pathway.
 
|}
 
|}
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==Fetal Head Growth==
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[[File:Fetal_head_growth_circumference_graph01.jpg|600px]]
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'''Head Circumference Growth''' (both gestational and post-fertilisation ages are shown)
  
 
==Skull Ossification==
 
==Skull Ossification==
[[File:Skull_superior.gif|thumb|Fetal Skull]]
 
 
These are 2 views of the same 12 week 92 mm CRL human fetus head, double stained to show both cartilage (blue) and newly-formed bone (red). The head undergoes two different forms of ossification (endochondral and intramembranous) in separate regions of the skull.
 
These are 2 views of the same 12 week 92 mm CRL human fetus head, double stained to show both cartilage (blue) and newly-formed bone (red). The head undergoes two different forms of ossification (endochondral and intramembranous) in separate regions of the skull.
  
[[File:Fetal head lateral.jpg|400px]]  
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{|
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|-bgcolor="CEDFF2"
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! Lateral view (external)
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!  Medial view (internal)
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|-
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| [[File:Fetal head lateral.jpg|400px]]  
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| [[File:Fetal head medial.jpg|400px]]
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|-
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| Note the distribution of new bone formation by '''intramembranous ossification''' in the plates of the cranial vault, temporal bone, orbit, upper jaw (maxilla) and lower jaw (mandible) regions. Bony regions in the lower jaw (mandible) region also show spaces where tooth formation is occurring.
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| Note the distribution of cartilage from the nasal region through the base of the skull showing '''endochondral ossification''', also occuring in the atlas/axis (with new bone forming). See also the original Meckel's cartilage within the newly forming bony mandible.
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|}
  
In this lateral (external) view, note the distribution of new bone formation by intramembranous ossification in the plates of the cranial vault, temporal bone, orbit, upper jaw (maxilla) and lower jaw (mandible) regions. (More? Skull | Face) Bony regions in the lower jaw (mandible) region also show spaces where tooth formation is occuring.
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[[File:Skull_superior.gif]]
  
[[File:Fetal head medial.jpg|400px]]
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Late Fetal Skull
 
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===Mandible Ossification===
In this medial (internal) view, note the distribution of cartilage from the nasal region through the base of the skull showing endochondral ossification, also occuring in the atlas/axis (with new bone forming). See also the original Meckel's cartilage within the newly forming bony mandible.
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[[File:Ossification_centre.jpg|400px]] [[File:Intramembranous_ossification_centre.jpg|400px]]
  
 
==Face==
 
==Face==
 
The cartilage template of the mandible and the base of the skull are replaced by early bone development.
 
The cartilage template of the mandible and the base of the skull are replaced by early bone development.
  
[[File:Fetal_head_section.jpg|400px]]
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[[File:Fetal_head_section.jpg|400px]] [[File:Fetal_head_section_01.jpg|400px]]
  
 
Selected midline medial head view showing key features of head musculoskeletal and neurological development.
 
Selected midline medial head view showing key features of head musculoskeletal and neurological development.
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==Palate Development==
 
==Palate Development==
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[[File:Bailey140.jpg|thumb|Early Fetal Palate]]
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Secondary palate formation is the growth of the palatal shelves towards the midline.
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{| border='0px'
 
{| border='0px'
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|-bgcolor="CEDFF2"
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! Inferior view
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! Anterior view
 
|-
 
|-
| [[File:Bailey140.jpg|300px]]
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| width=360px|<html5media height="400" width="400">File:Palate_001.mp4</html5media>
| [[File:Palate_001 icon.jpg|200px|link=Quicktime Development_Animation_-_Palate 1]]
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| width=360px|<html5media height="400" width="400">File:Palate_002.mp4</html5media>
| [[File:Palate_002 icon.jpg|200px|link=Quicktime Development_Animation_-_Palate 2]]
 
|-
 
| Embryonic Palate (week 7)
 
| [[Quicktime Development_Animation_-_Palate 1|Quicktime]] | [[Development_Animation_-_Palate 1|Flash]]
 
| [[Quicktime Development_Animation_-_Palate 2|Quicktime]] | [[Development_Animation_-_Palate 2|Flash]]
 
 
|-
 
|-
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| [[File:Palate_001_icon.jpg]]
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| [[File:Palate_002_icon.jpg]]
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|}
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[[File:Bailey140.jpg|thumb|Early Fetal Palate]]
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{| border='0px'
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| valign="bottom"|{{Palate 1}}
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| valign="bottom"|{{Palate 2}}
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| '''Palate Overview'''
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Embryonic
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* '''week 4''' - pharyngeal arch formation, first pharngeal arch contributes mandible and maxilla.
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* '''week 6 - 7''' - primary palate formation maxillary processes and frontonasal prominence.
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Fetal
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* '''week 9''' - secondary palate shelves fuse, separating oral and nasal cavities.
 
|}
 
|}
  
==Hearing==
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Week 10 Gestational Age ({{GA}} week 12)
  
* '''Week 9''' - Mesenchyme surrounding membranous labryinth (otic capsule) chondrifies. (More? Human 10 Week Fetus)
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{|
* '''Week 12-16''' - Capsule adjacent to membranous labryinth undegoes vacuolization to form a cavity (perilymphatic space) around membranous labrynth and fills with perilymph.
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| [[File:Fetal week 10 hard palate 07.jpg|400px]]
* '''Week 16-24''' - Centres of ossification appear in remaining cartilage of otic capsule form petrous portion of temporal bone. Continues to ossify to form mastoid process of temporal bone.
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* '''3rd Trimester''' - Vibration acoustically of maternal abdominal wall induces startle response in fetus.
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hard palate
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| [[File:Fetal_week_10_soft_palate_03.jpg|400px]]
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soft palate
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|}
  
===Central Pathway===
 
[[File:Auditory neural pathway.jpg|thumb|Auditory neural pathway]]
 
* '''26 weeks''' - human brainstem auditory pathway is anatomically formed.
 
* '''28 weeks''' - AABR can be recorded.
 
  
less than 34 weeks - latencies of AABR components (I, III, and V) decrease as a function of gestation
 
  
 
{{ANAT2341Lab6}}
 
{{ANAT2341Lab6}}

Latest revision as of 13:50, 9 September 2016

Lab 6: Introduction | Trilaminar Embryo | Early Embryo | Late Embryo | Fetal | Postnatal | Abnormalities | Online Assessment

Fetal Growth

Links: Fetal Development Movie | MP4 version | Fetal Development


In this cartoon movie of fetal growth, observe the changing relative sizes of the head, body and limbs.


Then consider fetal skeletal changes occurring within the head associated with ossification processes and palate development.


Finally consider fetal changes that are occurring in auditory pathway.

Fetal Head Growth

Fetal head growth circumference graph01.jpg

Head Circumference Growth (both gestational and post-fertilisation ages are shown)

Skull Ossification

These are 2 views of the same 12 week 92 mm CRL human fetus head, double stained to show both cartilage (blue) and newly-formed bone (red). The head undergoes two different forms of ossification (endochondral and intramembranous) in separate regions of the skull.

Lateral view (external) Medial view (internal)
Fetal head lateral.jpg Fetal head medial.jpg
Note the distribution of new bone formation by intramembranous ossification in the plates of the cranial vault, temporal bone, orbit, upper jaw (maxilla) and lower jaw (mandible) regions. Bony regions in the lower jaw (mandible) region also show spaces where tooth formation is occurring. Note the distribution of cartilage from the nasal region through the base of the skull showing endochondral ossification, also occuring in the atlas/axis (with new bone forming). See also the original Meckel's cartilage within the newly forming bony mandible.

Skull superior.gif

Late Fetal Skull

Mandible Ossification

Ossification centre.jpg Intramembranous ossification centre.jpg

Face

The cartilage template of the mandible and the base of the skull are replaced by early bone development.

Fetal head section.jpg Fetal head section 01.jpg

Selected midline medial head view showing key features of head musculoskeletal and neurological development.

Note extensive nasal cartilage, nasal conchae, pituitary, secondary palate, oral cavity, tongue, mandible, hyoid, choana, oropharynx.

Also note the developing tongue musculature and its mandibular attachment site.


Note that the cranial vault, the portion of the skull enclosing the brain, ossifies by a unique bone formation process, intramembranous ossification.

Because the head contains many different structures also review notes on Special Senses (eye, ear, nose), Respiration (pharynx), Integumentary (Teeth), Endocrine (thyroid, parathyroid, pituitary) and Musculoskeletal (tongue, skull).

Palate Development

Early Fetal Palate

Secondary palate formation is the growth of the palatal shelves towards the midline.

Inferior view Anterior view
Palate 001 icon.jpg Palate 002 icon.jpg
Early Fetal Palate
Palate 001 icon.jpg
 ‎‎Palate (oral view)
Page | Play
Palate 002 icon.jpg
 ‎‎Palate (front view)
Page | Play
Palate Overview

Embryonic

  • week 4 - pharyngeal arch formation, first pharngeal arch contributes mandible and maxilla.
  • week 6 - 7 - primary palate formation maxillary processes and frontonasal prominence.

Fetal

  • week 9 - secondary palate shelves fuse, separating oral and nasal cavities.

Week 10 Gestational Age (GA week 12)

Fetal week 10 hard palate 07.jpg

hard palate

Fetal week 10 soft palate 03.jpg

soft palate


Lab 6: Introduction | Trilaminar Embryo | Early Embryo | Late Embryo | Fetal | Postnatal | Abnormalities | Online Assessment

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Cite this page: Hill, M.A. (2019, November 17) Embryology ANAT2341 Lab 6 - Fetal. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/ANAT2341_Lab_6_-_Fetal

What Links Here?
© Dr Mark Hill 2019, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G