BGDA Practical 7 - Week 8: Difference between revisions

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===Embryo Stages and Events===
===Embryo Stages and Events===


{| class="prettytable"
{| class="prettytable"
| width= "50px" | '''Day'''
|-bgcolor="DDCEF2"
| width= "100px" | '''Stage'''
| <center>'''Day'''</center>
| width=100px | <center>'''Stage'''</center>
| '''Event'''
| '''Event'''


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| [[File:Stage20_bf1c.jpg|200px|link=Carnegie stage 20]]  
| [[File:Stage20_bf1c.jpg|200px|link=Carnegie stage 20]]  


[http://embryology.med.unsw.edu.au/Notes/head.htm Head]  scalp vascular plexus visible  
[[Head Development|Head]]  scalp vascular plexus visible  


[http://embryology.med.unsw.edu.au/Notes/skmus7.htm Limb]  upper limbs begin to rotate ventrally  
[[Musculoskeletal_System_-_Limb_Development|Limb]]  upper limbs begin to rotate ventrally  


[http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural] amygdaloid body has at least four individual nuclei [http://www.ncbi.nlm.nih.gov/pubmed/2268071 PMID: 2268071]
[[Neural_System_Development|Neural]] - amygdaloid body has at least four individual nuclei<ref><pubmed>2268071</pubmed></ref>


oculomotor nerve shows a dorsolateral and a ventromedial portion  
oculomotor nerve shows a dorsolateral and a ventromedial portion  
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choroid plexuses of the fourth and lateral ventricles  
choroid plexuses of the fourth and lateral ventricles  


|-
|-bgcolor="FAF5FF"
| <center>51</center>
| <center>51</center>
| &nbsp;
| &nbsp;
| [http://embryology.med.unsw.edu.au/Notes/git.htm Gastrointestinal Tract] anal membrane perforates
| [[Gastrointestinal Tract Development|Gastrointestinal Tract]] anal (cloacal) membrane perforates


|-
|-
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| [[File:Stage21_bf1c.jpg|200px|link=Carnegie stage 21]]
| [[File:Stage21_bf1c.jpg|200px|link=Carnegie stage 21]]


[http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural] cortical plate appears in the area of future insula [http://www.ncbi.nlm.nih.gov/pubmed/2252222 PMID: 2252222]
[[Neural_System_Development|Neural]] - cortical plate appears in the area of future insula<ref name="PMID2252222"><pubmed>2252222</pubmed></ref>


[http://embryology.med.unsw.edu.au/Notes/skmus7.htm Limb]  upper and lower limbs rotate  
[[Musculoskeletal_System_-_Limb_Development|Limb]]  upper and lower limbs rotate  


[http://embryology.med.unsw.edu.au/Notes/coelom.htm Intraembryonic Coelom]  pericardioperitoneal canals close  
[[Coelomic Cavity Development|Intraembryonic Coelom]]  pericardioperitoneal canals close  


|-
|-bgcolor="FAF5FF"
| <center>53</center>
| <center>53</center>
| &nbsp;
| &nbsp;
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| <center>54</center>
| <center>54</center>
| [[Carnegie stage 22|Stage 22]]   
| [[Carnegie stage 22|Stage 22]]   
| [[File:Stage22_bf1c.jpg|200px|link=Carnegie stage 22]][http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural] neocortical fibres project to epithalamus, to dorsal thalamus, and to mesencephalon [http://www.ncbi.nlm.nih.gov/pubmed/2252222 PMID: 2252222]
| [[File:Stage22_bf1c.jpg|200px|link=Carnegie stage 22]][[Neural_System_Development|Neural]] - neocortical fibres project to epithalamus, to dorsal thalamus, and to mesencephalon<ref name="PMID2252222" />


[http://embryology.med.unsw.edu.au/Notes/skmus7.htm Limb]  fingers and toes lengthen
[[Musculoskeletal_System_-_Limb_Development|Limb]]  fingers and toes lengthen


[http://embryology.med.unsw.edu.au/Notes/nose.htm Sense - Smell]  Stage 22 to early fetal period - migratory streams of neurons from the subventricular zone of the olfactory bulb towards the future claustrum [http://www.ncbi.nlm.nih.gov/pubmed/15604533 PMID: 15604533]
[[Sensory_-_Smell_Development|Sense - Smell]]  Stage 22 to early fetal period - migratory streams of neurons from the subventricular zone of the olfactory bulb towards the future claustrum<ref name="PMID15604533"><pubmed>15604533</pubmed></ref>


|-
|-bgcolor="FAF5FF"
| <center>55</center>
| <center>55</center>
|  
|  
| [http://embryology.med.unsw.edu.au/Notes/genital.htm Genital ]8 Weeks  Testis - mesenchyme, interstitial cells (of Leydig) secrete testosterone, androstenedione  
| [[Genital System Development|Genital]] 8 Weeks  Testis - mesenchyme, interstitial cells (of Leydig) secrete testosterone, androstenedione  


[http://embryology.med.unsw.edu.au/Notes/genital.htm Genital ]8 to 12 Weeks - hCG stimulates testosterone production  
[[Genital System Development|Genital]] 8 to 12 Weeks - hCG stimulates testosterone production  


[http://embryology.med.unsw.edu.au/Notes/tongue.htm Tongue]  Week 8 - nerves penetrate epitheilai basal lamina and synapse with undifferentiated, elongated, epithelial cells (taste bud progenitor cell)  
[[Tongue_Development|Tongue]]  Week 8 - nerves penetrate epitheilai basal lamina and synapse with undifferentiated, elongated, epithelial cells (taste bud progenitor cell)  


|-
|-
| <center>56</center>
| <center>56</center>
| [[Carnegie stage 23|Stage 23]]   
| [[Carnegie stage 23|Stage 23]]   
| [[File:Stage23_bf1c.jpg|200px|link=Carnegie stage 23]] [http://embryology.med.unsw.edu.au/wwwhuman/Stages/Stage23L.htm  ]Stage 23 defines the end of the embryonic (organogenesis) period  
| [[File:Stage23_bf1c.jpg|200px|link=Carnegie stage 23]] [[Carnegie stage 23|Stage 23]] defines the end of the embryonic (organogenesis) period  


'''Mesoderm ''' heart prominence, ossification continues
'''Mesoderm ''' heart prominence, ossification continues


[http://embryology.med.unsw.edu.au/Notes/head.htm Head]  nose, eye, external acoustic meatus, eyelids, external ears, rounded head
[[Head Development|Head]]  nose, eye, external acoustic meatus, eyelids, external ears, rounded head


'''Body '''- straightening of trunk, heart, liver, umbilical cord, intestines herniated at umbilicus
'''Body '''- straightening of trunk, heart, liver, umbilical cord, intestines herniated at umbilicus


[http://embryology.med.unsw.edu.au/Notes/skmus7.htm Limb]  upper limbs longer and bent at elbow, hands and feet turned inward, foot with separated digits, wrist, hand with separated digits
[[Musculoskeletal_System_-_Limb_Development|Limb]]  upper limbs longer and bent at elbow, hands and feet turned inward, foot with separated digits, wrist, hand with separated digits


'''Extraembryonic Coelom'''  chorionic cavity is now lost by fusion with the expanding amniotic cavity
'''Extraembryonic Coelom'''  chorionic cavity is now lost by fusion with the expanding amniotic cavity


[http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural] rhombencephalon, pyramidal decussation present, nuclei and tracts similar to those present in the newborn cerebellum present as only a plate connected to midbrain and hindbrain through fibre bundles [http://www.ncbi.nlm.nih.gov/pubmed/2244584 PMID: 2244584]
[[Neural_System_Development|Neural]] - rhombencephalon, pyramidal decussation present, nuclei and tracts similar to those present in the newborn cerebellum present as only a plate connected to midbrain and hindbrain through fibre bundles<ref name="PMID2244584"><pubmed>2244584</pubmed></ref>


[http://embryology.med.unsw.edu.au/Notes/skmus8.htm Axial Skeleton] vertebral column 33 or 34 cartilaginous vertebrae (20-33 mm in total length), vertebral pedicles, articular and transverse processes identifiable (no spinous processes) [http://www.ncbi.nlm.nih.gov/pubmed/7216919 PMID: 7216919]
[[Musculoskeletal_System_-_Axial_Skeleton_Development|Axial Skeleton]] vertebral column 33 or 34 cartilaginous vertebrae (20-33 mm in total length), vertebral pedicles, articular and transverse processes identifiable (no spinous processes)<ref name="PMID7216919"><pubmed>7216919</pubmed></ref>


|-
|-bgcolor="FAF5FF"
| <center>&nbsp;</center>
| <center>&nbsp;</center>
| Week 8
| Week 8
| [http://embryology.med.unsw.edu.au/Notes/git10.htm GIT - Stomach] - Week 8 - Gastrin containing cells in stomach antrum. Somatostatin cells in both the antrum and the fundus.
| [[Gastrointestinal_Tract_-_Stomach_Development|Stomach]] - Week 8 - Gastrin containing cells in stomach antrum. Somatostatin cells in both the antrum and the fundus.


|}
|}
==References==
<references/>






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{{BGDALab7}}


{{Template:BGDAFooter}}


[[Category:Week 8]]
[[Category:Week 8]]

Revision as of 08:25, 20 May 2013

Introduction

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Practical 6: Week 3 | Week 4 | Week 5 | Week 6 | Week 7 | Week 8


Key Events of Human Development during the eighth week (week 8) following fertilization or Clinical week 10 (LMP).


This page will give an overview of limb and neural development and look at other system organization compared with the earlier stages.

  • Stage 20

    Stage 20

  • Stage 21

    Stage 21

  • Stage 22

    Stage 22

  • Stage 23

    Stage 23


  • Stage 20 - right

    Stage 20 - right

  • Stage 20 - ventral

    Stage 20 - ventral

  • Stage 20 - left

    Stage 20 - left

  • Stage 21 - right

    Stage 21 - right

  • Stage 21 - ventral

    Stage 21 - ventral

  • Stage 21 - left

    Stage 21 - left

  • Stage 22 - right

    Stage 22 - right

  • Stage 22 - ventral

    Stage 22 - ventral

  • Stage 22 - left

    Stage 22 - left

  • Stage 23 - right

    Stage 23 - right

  • Stage 23 - ventral

    Stage 23 - ventral

  • Stage 22 - left

    Stage 22 - left

  • Stage 22 - dorsal

    Stage 22 - dorsal

Limbs

Human Embryo (Stage19) limb rotation
  • Limb upper and lower limbs rotate in different directions (upper limb dorsally, lower limb ventrally)
  • see also Adult dermatomes

Stage20-23 limbs.jpg

Gastrointestinal Tract

Gastrointestinal tract herniation

Stage22-GIT-icon.jpg

Neural

Cross-section of head (stage 22) Neural - early developing cortex

Stage22-CNS-icon.jpg

Other Embryo Systems

Movies - Embryo Carnegie stage 22 - These are rotating animations based upon reconstruction of a human embryo (stage 22) serial slice images.

Stage22-CVS-icon.jpg Stage22-SK-icon.jpg Stage22-UG-icon.jpg
Cardiovascular Skeletal Urogenital

Critical Periods

Conceptus Embryonic development (weeks) Fetal period (weeks)
1
2
3
4
5
6
7
8
9
16
20-36
38
Early zygote.jpg Week2 001 icon.jpg Stage9 sem4c.jpg Stage13 sem1c.jpg Stage15 bf1c.jpg Stage17 bf1c.jpg Stage19 bf1c.jpg Stage23 bf1c.jpg
Neural
Stage2.jpg Heart
Upper limbs
Lower limbs
Ear
Eye
CSt3.jpg Palate
Teeth
Week2 001 icon.jpg External genitalia
Loss Major abnormalities Functional and Minor abnormalities



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Practical 6: Week 3 | Week 4 | Week 5 | Week 6 | Week 7 | Week 8



   

Additional Information

Additional Information - Content shown under this heading is not part of the material covered in this class. It is provided for those students who would like to know about some concepts or current research in topics related to the current class page.


Detailed Week by Week

The following information is a detailed timeline of embryonic development between week 3 to 8 and content does not form part of the current practical class.

Week 3 | Week 4 | Week 5 | Week 6 | Week 7 | Week 8


Embryo Stages and Events

Day
Stage
 Event
50
 Stage 20 Stage20 bf1c.jpg

Head scalp vascular plexus visible

Limb upper limbs begin to rotate ventrally

Neural - amygdaloid body has at least four individual nuclei[1]

oculomotor nerve shows a dorsolateral and a ventromedial portion

rhombic lip (rhombencephalon) formation of the cerebellum (intermediate layer) and of the cochlear nuclei

cerebellum cell layer (future Purkinje cells) develops

choroid plexuses of the fourth and lateral ventricles

51
   Gastrointestinal Tract anal (cloacal) membrane perforates
52
 Stage 21 Stage21 bf1c.jpg

Neural - cortical plate appears in the area of future insula[2]

Limb upper and lower limbs rotate

Intraembryonic Coelom pericardioperitoneal canals close

53
    
54
 Stage 22 Stage22 bf1c.jpgNeural - neocortical fibres project to epithalamus, to dorsal thalamus, and to mesencephalon[2]

Limb fingers and toes lengthen

Sense - Smell Stage 22 to early fetal period - migratory streams of neurons from the subventricular zone of the olfactory bulb towards the future claustrum[3]

55
 Genital 8 Weeks Testis - mesenchyme, interstitial cells (of Leydig) secrete testosterone, androstenedione

Genital 8 to 12 Weeks - hCG stimulates testosterone production

Tongue Week 8 - nerves penetrate epitheilai basal lamina and synapse with undifferentiated, elongated, epithelial cells (taste bud progenitor cell)

56
 Stage 23 Stage23 bf1c.jpg Stage 23 defines the end of the embryonic (organogenesis) period

Mesoderm heart prominence, ossification continues

Head nose, eye, external acoustic meatus, eyelids, external ears, rounded head

Body - straightening of trunk, heart, liver, umbilical cord, intestines herniated at umbilicus

Limb upper limbs longer and bent at elbow, hands and feet turned inward, foot with separated digits, wrist, hand with separated digits

Extraembryonic Coelom chorionic cavity is now lost by fusion with the expanding amniotic cavity

Neural - rhombencephalon, pyramidal decussation present, nuclei and tracts similar to those present in the newborn cerebellum present as only a plate connected to midbrain and hindbrain through fibre bundles[4]

Axial Skeleton vertebral column 33 or 34 cartilaginous vertebrae (20-33 mm in total length), vertebral pedicles, articular and transverse processes identifiable (no spinous processes)[5]

 
 Week 8 Stomach - Week 8 - Gastrin containing cells in stomach antrum. Somatostatin cells in both the antrum and the fundus.

References

  1. ↑ <pubmed>2268071</pubmed>
  2. ↑ 2.0 2.1 <pubmed>2252222</pubmed>
  3. ↑ <pubmed>15604533</pubmed>
  4. ↑ <pubmed>2244584</pubmed>
  5. ↑ <pubmed>7216919</pubmed>



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Practical 6: Week 3 | Week 4 | Week 5 | Week 6 | Week 7 | Week 8


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