Template:First Trimester Timeline: Difference between revisions

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{|
== Week -2 ==
|+ colspan=3|'''First Trimester Timeline'''
({{GA}} Week 1)
 
 
{| class="prettytable" width=100%
|-bgcolor="FAF5FF"
| <center>'''Day'''</center>
| width="100px"|<center>'''Menstrual cycle'''</center>
| '''Event'''
 
|-
|-
| <center>1</center>
| Menstrual Phase
| [[File:Menstrual cycle.png|90px|left|link=Menstrual Cycle]]
[[Menstrual Cycle]] changes: Uterine endometrium (loss), Ovary (Follicle Development)
|-bgcolor="F5FAFF"
| <center>2</center>
| &nbsp;
| [[File:Human-_menstrual_uterine_endometrium.jpg|90px|link=Menstrual_Cycle_-_Histology]]
|-
| <center>3</center>
| &nbsp;
|  
|  
| colspan=2|{{human timeline}} | [[Template:First Trimester Timeline|First Trimester Timeline]] | [[Template:Second Trimester Timeline|Second Trimester Timeline]] | [[Template:Third Trimester Timeline|Third Trimester Timeline]]
 
|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
! colspan=3 | [[Week 1]] ({{GA}} Clinical Week 3)  
| <center>4</center>
|-bgcolor="#AFEEEE"
| &nbsp;
| &nbsp;
 
|-
| <center>5</center>
| Proliferative Phase
| [[File:Smear- early proliferative.jpg|90px|link=Menstrual_Cycle_-_Histology]][[File:Ova41he.jpg|90px|link=Menstrual Cycle]] [[Menstrual Cycle]] changes: Uterine endometrium (proliferation), Ovary (Follicle Development)
 
|-bgcolor="F5FAFF"
| <center>6</center>
|
|
 
|-
| <center>7</center>
| &nbsp;
| &nbsp;
 
|}
 
== Week -1 ==
({{GA}} Week 2)
 
 
{| class="prettytable" width=100%
|-bgcolor="F5FAFF"
| <center>'''Day'''</center>
| width="100px"|'''Menstrual cycle'''
| '''Event'''
 
|-
| <center>8</center>
| Proliferative Phase
|
 
|-bgcolor="F5FAFF"
| <center>9</center>
| &nbsp;
| [[File:Smear-_mid-proliferative.jpg|90px|link=Menstrual_Cycle_-_Histology]] [[File:Human-_mid-proliferative_uterine_endometrium.jpg|90px|link=Menstrual_Cycle_-_Histology]] [[File:Ovary10x.jpg|90px]] [[File:Ova20he.jpg|90px]] [[Menstrual Cycle]] - Mid proliferative
 
|-
| <center>10</center>
| &nbsp;
| &nbsp;
 
|-bgcolor="F5FAFF"
| <center>11</center>
| &nbsp;
| &nbsp;
 
|-
| <center>12</center>
| &nbsp;
| &nbsp;
 
|-bgcolor="F5FAFF"
| <center>13</center>
| &nbsp;
| [[File:Smear-_late-proliferative.jpg|90px|link=Menstrual_Cycle_-_Histology]] [[File:Human-_late_proliferative_uterine_endometrium.jpg|90px|link=Menstrual_Cycle_-_Histology]] [[File:Menstrual cycle.png|90px|link=Menstrual Cycle]] [[Menstrual Cycle]] - Late Proliferative
 
|-
| <center>14</center>
| Ovulation
 
Capacitation
| [[File:Human_ovulation_06.jpg|90px]] [[Image:Human oocyte.jpg|90px]] [[File:Follicle 001 icon.jpg|90px|link=Ovulation Movie]]
 
|}
 
== Week 1 ==
[[Week 1]] ({{GA}} Clinical Week 3)  
 
[[File:Week1_summary.jpg|thumb|Week 1 summary]]
{| class="prettytable" width=75%
|-bgcolor="F5FAFF"
| <center>'''Day'''</center>
| <center>'''Day'''</center>
| width="100px"|<center>'''Stage'''</center>
| width="100px"|<center>'''Stage'''</center>
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| Secretory Phase
| Secretory Phase


[[Carnegie stage 1|Stage 1]]
[[Carnegie stage 1|'''Stage 1''']]
| [[Image:Early_zygote.jpg|90px]] [[File:Stage1 size with ruler.jpg|90px]][[File:Smear-_secretory.jpg|90px|link=Menstrual_Cycle_-_Histology]] [[File:Human-_secretory_uterine_endometrium.jpg|90px|link=Menstrual_Cycle_-_Histology]] [[Fertilization]], Secretory Phase  
| [[Image:Early_zygote.jpg|90px]] [[File:Stage1 size with ruler.jpg|90px]][[File:Smear-_secretory.jpg|90px|link=Menstrual_Cycle_-_Histology]] [[File:Human-_secretory_uterine_endometrium.jpg|90px|link=Menstrual_Cycle_-_Histology]] [[Fertilization]], Secretory Phase  


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>2</center>
| <center>2</center>
| [[Carnegie stage 2|Stage 2]]
| [[Carnegie stage 2|'''Stage 2''']]
| [[Image:Stage2.jpg|90px]] [[File:Week1 001 icon.jpg|90px|link=Week 1 Movie]] [[Morula]], Blastula
| [[Image:Stage2.jpg|90px]] [[File:Week1 001 icon.jpg|90px|link=Week 1 Movie]] [[Morula]], Blastula


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| [[File:Human-blastocyst-day-3-6-icon.jpg|90px|link=Blastocyst Day 3-6 Movie]] [[Blastocyst Development]]
| [[File:Human-blastocyst-day-3-6-icon.jpg|90px|link=Blastocyst Day 3-6 Movie]] [[Blastocyst Development]]


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>4</center>
| <center>4</center>
| [[Carnegie stage 3|Stage 3]]
| [[Carnegie stage 3|'''Stage 3''']]
| [[Image:CSt3.jpg|90px]] Blastocyst Hatching (zona pellucida lost)  
| [[Image:CSt3.jpg|90px]] Blastocyst Hatching (zona pellucida lost)  


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| [[File:Smear-_late_secretory.jpg|90px]] [[File:Human-_late_secretory_uterine_endometrium.jpg|90px]] Late Secretory, Blastocyst (free floating)
| [[File:Smear-_late_secretory.jpg|90px]] [[File:Human-_late_secretory_uterine_endometrium.jpg|90px]] Late Secretory, Blastocyst (free floating)


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>6</center>
| <center>6</center>
| [[Carnegie stage 4|Stage 4]]
| [[Carnegie stage 4|'''Stage 4''']]
| [[Implantation|Adplantation]]
| [[Implantation|Adplantation]]


|-
|-
| <center>7</center>
| <center>7</center>
| [[Carnegie stage 5|Stage 5]]
| [[Carnegie stage 5|'''Stage 5''']]
| [[File:Week2_001 icon.jpg|90px|link=Implantation_Movie]][[File:Stage5_bf11L.jpg|90px|link=Carnegie stage 5]]
| [[File:Week2_001 icon.jpg|90px|link=Implantation_Movie]][[File:Stage5_bf11L.jpg|90px|link=Carnegie stage 5]]
|-
 
! colspan=3 | [[Week 2]] ({{GA}} Clinical Week 4)  
|}
|-bgcolor="#AFEEEE"
 
== Week 2 ==
[[Week 2]] ({{GA}} Week 4)  
 
 
{| class="prettytable" width=100%
|-bgcolor="F5FAFF"
| <center>'''Day'''</center>
| <center>'''Day'''</center>
| <center>'''Stage'''</center>
| <center>'''Stage'''</center>
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|  [[File:Week2_001 icon.jpg|90px|link=Implantation_Movie]] [[Implantation]]
|  [[File:Week2_001 icon.jpg|90px|link=Implantation_Movie]] [[Implantation]]


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>9</center>
| <center>9</center>
| &nbsp;
| &nbsp;
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| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>11</center>
| <center>11</center>
| &nbsp;
| &nbsp;
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| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>13</center>
| <center>13</center>
| [[Carnegie stage 6|Stage 6]]
| [[Carnegie stage 6|'''Stage 6''']]
| [[File:Stage6_bf03.jpg|90px|link=Carnegie stage 6]][[File:Chorion 001 icon.jpg|90px|link=Development Animation - Chorionic Cavity]] Chorionic Cavity
| [[File:Stage6_bf03.jpg|90px|link=Carnegie stage 6]][[File:Chorion 001 icon.jpg|90px|link=Development Animation - Chorionic Cavity]] Chorionic Cavity


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| &nbsp;
| &nbsp;
| &nbsp;
| &nbsp;
|-
 
! colspan=3 | [[Week 3]] ({{GA}} Clinical Week 5)  
|}
|-bgcolor="#AFEEEE"
 
== Week 3 ==
[[Week 3]] ({{GA}} Week 5)  
 
 
{| class="prettytable" width=100%
|-bgcolor="F5FAFF"
| <center>'''Day'''</center>
| <center>'''Day'''</center>
| <center>'''Stage'''</center>
| <center>'''Stage'''</center>
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|  
|  


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>16</center>
| <center>16</center>
| [[Carnegie stage 7|Stage 7]]
| [[Carnegie stage 7|'''Stage 7''']]
| [[File:Stage7-bf1.jpg|90px|link=Carnegie_stage_7]] [[File:Stage7-sem2.jpg|90px|link=Carnegie_stage_7]] [[Image:Stage7.jpg|90px|link=Carnegie_stage_7]]
| [[File:Stage7-bf1.jpg|90px|link=Carnegie_stage_7]] [[File:Stage7-sem2.jpg|90px|link=Carnegie_stage_7]] [[Image:Stage7.jpg|90px|link=Carnegie_stage_7]]


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| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>18</center>
| <center>18</center>
| [[Carnegie stage 8|Stage 8]]
| [[Carnegie stage 8|'''Stage 8''']]
| [[Image:Stage8_human.jpg|90px|link=Carnegie_stage_8]] [[File:Neuralplate_001 icon.jpg|90px|link=Development Animation - Neural Plate]] [[Neural System Development|Neural]] neurogenesis, neural groove and folds are first seen
| [[Image:Stage8_human.jpg|90px|link=Carnegie_stage_8]] [[File:Neuralplate_001 icon.jpg|90px|link=Development Animation - Neural Plate]] {{neural}} neurogenesis, neural groove and folds are first seen


|-
|-
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| [[Image:Stage8_SEM1.jpg|90px|left]]
| [[Image:Stage8_SEM1.jpg|90px|left]]


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>20</center>
| <center>20</center>
| [[Carnegie stage 9|Stage 9]]
| [[Carnegie stage 9|'''Stage 9''']]
| [[File:Stage9_bf2c.jpg|90px|link=Carnegie_stage_9]] [[File:Stage9_sem1b.jpg|90px|link=Carnegie_stage_9]] [[Musculoskeletal_System_Development|Musculoskeletal]]  somitogenesis, first somites form and continue to be added in sequence caudally (1 - 3 somite pairs).
| [[File:Stage9_bf2c.jpg|90px|link=Carnegie_stage_9]] [[File:Stage9_sem1b.jpg|90px|link=Carnegie_stage_9]] [[Musculoskeletal_System_Development|Musculoskeletal]]  somitogenesis, first somites form and continue to be added in sequence caudally (1 - 3 somite pairs).


[[Neural System Development|Neural]] the three main divisions of the brain, which are not cerebral vesicles, can be distinguished while the neural groove is still completely open
{{neural}} the three main divisions of the brain, which are not cerebral vesicles, can be distinguished while the neural groove is still completely open


[[Neural Crest Development|Neural Crest]]  mesencephalic neural crest is visible<ref name="PMID17848161"><pubmed>17848161</pubmed></ref>
[[Neural Crest Development|Neural Crest]]  mesencephalic neural crest is visible{{#pmid:17848161|PMID17848161}}
|-
|-
| <center>21</center>
| <center>21</center>
| &nbsp;
| &nbsp;
| [[Cardiovascular System Development|Heart]]  cardiogenesis, week 3 begins as paired heart tubes.
| [[Cardiovascular System Development|Heart]]  cardiogenesis, week 3 begins as paired heart tubes.
|-
 
! colspan=3 | [[Week 4]] ({{GA}} Clinical Week 6)  
|}
|-bgcolor="#AFEEEE"
 
== Week 4 ==
[[Week 4]] ({{GA}} Week 6)  
 
 
{| class="prettytable" width=100%
|-bgcolor="F5FAFF"
| <center>'''Day'''</center>
| <center>'''Day'''</center>
| <center>'''Stage'''</center>
| <center>'''Stage'''</center>
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|-
|-
| <center>22</center>
| <center>22</center>
| [[Carnegie stage 10|Stage 10]]
| [[Carnegie stage 10|'''Stage 10''']]
| [[File:Stage10_bf2c.jpg|90px|link=Carnegie_stage_10]] [[File:Stage10_sem10c.jpg|90px|link=Carnegie_stage_10]] [[File:Neuraltube_001 icon.jpg|90px|link=Development Animation - Neural Tube]]
| [[File:Stage10_bf2c.jpg|90px|link=Carnegie_stage_10]] [[File:Stage10_sem10c.jpg|90px|link=Carnegie_stage_10]] [[File:Neuraltube_001 icon.jpg|90px|link=Development Animation - Neural Tube]]


[[Neural Crest Development|Neural Crest]] differentiation at spinal cord level from day 22 until day 26  
[[Neural Crest Development|Neural Crest]] differentiation at spinal cord level from day 22 until day 26  


[[Neural System Development|Neural]] neural folds begin to fuse near the junction between brain and spinal cord, when [[Neural Crest Development|Neural Crest]] cells are arising mainly from the neural ectoderm  
{{neural}} folds begin to fuse near the junction between brain and spinal cord, when [[Neural Crest Development|Neural Crest]] cells are arising mainly from the neural ectoderm  


[[Neural Crest Development|Neural Crest]] trigeminal, facial, and postotic ganglia components visible<ref name="PMID17848161"><pubmed>17848161</pubmed></ref>
[[Neural Crest Development|Neural Crest]] trigeminal, facial, and postotic ganglia components visible{{#pmid:17848161|PMID17848161}}


[[Neural Crest Development|Neural Crest]]  migration of vagal level neural crest cells begins (7-10 somite stage)  
[[Neural Crest Development|Neural Crest]]  migration of vagal level neural crest cells begins (7-10 somite stage)  


[[Neural System Development|Neural]] rostral neural tube forms 3 primary brain vesicles (week 4)  
{{neural}} rostral neural tube forms 3 primary brain vesicles (week 4)  


[[Respiratory_System_Development|Respiratory]]  Week 4 - laryngotracheal groove forms on floor foregut.
[[Respiratory_System_Development|Respiratory]]  Week 4 - laryngotracheal groove forms on floor foregut.


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>23</center>
| <center>23</center>
| &nbsp;
| &nbsp;
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[[Endocrine_-_Thyroid_Development|Thyroid]] thyroid median endodermal thickening in the floor of pharynx  
[[Endocrine_-_Thyroid_Development|Thyroid]] thyroid median endodermal thickening in the floor of pharynx  


[[Neural System Development|Neural]] rostral (or cephalic) neuropore closes within a few hours; closure is bidirectional, it takes place from the dorsal and terminal lips and may occur in two areas simultaneously. The two lips, however, behave differently.  
{{neural}} rostral (or cephalic) neuropore closes within a few hours; closure is bidirectional, it takes place from the dorsal and terminal lips and may occur in two areas simultaneously. The two lips, however, behave differently.  


[[Neural_-_Ventricular_System_Development|Ventricular System]] Optic ventricle appears and the neural groove/tube space is initially filled with amniotic fluid.<ref name="PMID2285038"><pubmed>2285038</pubmed></ref>
[[Neural_-_Ventricular_System_Development|Ventricular System]] Optic ventricle appears and the neural groove/tube space is initially filled with amniotic fluid.{{#pmid:2285038|PMID2285038}}


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>25</center>
| <center>25</center>
| [[Carnegie stage 12|Stage 12]]  
| [[Carnegie stage 12|Stage 12]]  
| [[File:Stage12_bf2b.jpg|90px|link=Carnegie_stage_12]] [[File:Stage12 sem1.jpg|90px|link=Carnegie_stage_12]]
| [[File:Stage12_bf2b.jpg|90px|link=Carnegie_stage_12]] [[File:Stage12 sem1.jpg|90px|link=Carnegie_stage_12]]


[[Endocrine_-_Pituitary_Development|Pituitary]] Week 4  hypophysial pouch, Rathke's pouch, diverticulum from roof  
{{pituitary}} Week 4  hypophysial pouch, Rathke's pouch, diverticulum from roof  


[[Gastrointestinal_Tract_-_Liver_Development|Liver]] septum transversum forming liver stroma and hepatic diverticulum forming hepatic trabeculae<ref name="PMID9407542"><pubmed>9407542</pubmed></ref>
{{liver}} septum transversum forming liver stroma and hepatic diverticulum forming hepatic trabeculae{{#pmid:9407542|PMID9407542}}


[[Neural System Development|Neural]] caudal neuropore takes a day to close (closure is approximately at future somitic pair 31/sacral vertebra 2)  
{{neural}} caudal neuropore takes a day to close (closure is approximately at future somitic pair 31/sacral vertebra 2)  


[[Neural System Development|Neural]] secondary neurulation begins  
{{neural}} secondary neurulation begins  


[[Neural_-_Ventricular_System_Development|Ventricular System]] onset of the ventricular system and separates the ependymal from the amniotic fluid.<ref name="PMID2285038" />
[[Neural_-_Ventricular_System_Development|Ventricular System]] onset of the ventricular system and separates the ependymal from the amniotic fluid.{{#pmid:2285038|PMID2285038}}


[[Neural Crest Development|Neural Crest]] cardiac crest, neural crest from rhombomeres 6 and 7 that migrates to pharyngeal arch 3 and from there the truncus arteriosus <ref name="PMID17848161" />
{{neural crest}} cardiac crest, neural crest from rhombomeres 6 and 7 that migrates to pharyngeal arch 3 and from there the truncus arteriosus{{#pmid:17848161|PMID17848161}}


[[Neural Crest Development|Neural Crest]] vagal neural crest enter the foregut (20-25 somite stage)
[[Neural Crest Development|Neural Crest]] vagal neural crest enter the foregut (20-25 somite stage)
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| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>27</center>
| <center>27</center>
| &nbsp;
| &nbsp;
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| <center>28</center>
| <center>28</center>
| [[Carnegie stage 13|Stage 13]]
| [[Carnegie stage 13|Stage 13]]
| [[File:Stage13_bf1c.jpg|90px|link=Carnegie_stage_13]] [[File:Stage13_sem1c.jpg|90px|link=Carnegie_stage_13]] [[Neural System Development|Neural]] the neural tube is normally completely closed, ventricular system now separated from amniotic fluid. Neural crest at spinal level is segregating, and spinal ganglia are in series with the somites. Spinal cord ventral roots beginning to develop.<ref name="PMID3354839"><pubmed>3354839</pubmed></ref>
| [[File:Stage13_bf1c.jpg|90px|link=Carnegie_stage_13]] [[File:Stage13_sem1c.jpg|90px|link=Carnegie_stage_13]] {{neural}} the neural tube is normally completely closed, ventricular system now separated from amniotic fluid. Neural crest at spinal level is segregating, and spinal ganglia are in series with the somites. Spinal cord ventral roots beginning to develop.{{#pmid:3354839|PMID3354839}}


telencephalon cavity appears  
telencephalon cavity appears  


[[Neural - Vascular Development]] - hindbrain is supplied by two parallel neural arteries (or channels) that obtain their blood supply from carotid-vertebrobasilar anastomoses given by the pharyngeal arch arteries; trigeminal artery, the otic artery, hypoglossal artery, and the proatlantal artery.<ref name="PMID26060802"><pubmed>26060802</pubmed>| [http://synapse.koreamed.org/DOIx.php?id=10.5853/jos.2015.17.2.144 J Stroke.]</ref>
[[Neural - Vascular Development]] - hindbrain is supplied by two parallel neural arteries (or channels) that obtain their blood supply from carotid-vertebrobasilar anastomoses given by the pharyngeal arch arteries; trigeminal artery, the otic artery, hypoglossal artery, and the proatlantal artery.{{#pmid:26060802|PMID26060802}}


[[Gastrointestinal_Tract_-_Liver_Development|Liver]] epithelial cord proliferation enmeshing stromal capillaries<ref name="PMID9407542" />
[[Gastrointestinal_Tract_-_Liver_Development|Liver]] epithelial cord proliferation enmeshing stromal capillaries{{#pmid:9407542|PMID9407542}}


[[Sensory_-_Smell_Development|Smell]]  Crest comes from the nasal plates<ref name="PMID15604533"><pubmed>15604533</pubmed></ref>
[[Sensory_-_Smell_Development|Smell]]  Crest comes from the nasal plates{{#pmid:15604533|PMID15604533}}


[[Integumentary_System_Development|Skin]] 4 weeks - simple ectoderm epithelium over mesenchyme  
[[Integumentary_System_Development|Skin]] 4 weeks - simple ectoderm epithelium over mesenchyme  
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[[Integumentary_System_Development|Skin]] 1-3 months ectoderm- germinative (basal) cell repeated division of generates stratified epithelium; mesoderm- differentiates into connective tissue and blood vessels
[[Integumentary_System_Development|Skin]] 1-3 months ectoderm- germinative (basal) cell repeated division of generates stratified epithelium; mesoderm- differentiates into connective tissue and blood vessels


[[Sensory_-_Vision_Development|Vision]] Optic vesicle lies close to the surface ectoderm. The surface ectoderm overlying the optic vesicle, in response to this contact, has thickened to form the lens placode.<ref name="PMID7364662"><pubmed>7364662</pubmed></ref>
{{vision}} Optic vesicle lies close to the surface ectoderm. The surface ectoderm overlying the optic vesicle, in response to this contact, has thickened to form the lens placode.{{#pmid:7364662|PMID7364662}}
 
[[Respiratory_System_-_Diaphragm|Diaphragm]] - pleuroperitoneal fold (PPF) first discernible in human embryos (CRL 6mm).{{#pmid:19711422|PMID19711422}}
|}
 
== Week 5 ==
[[Week 5]] ({{GA}} Clinical Week 7)
 


[[Respiratory_System_-_Diaphragm|Diaphragm]] - pleuroperitoneal fold (PPF) first discernible in human embryos (CRL 6mm).<ref name=PMID19711422><pubmed>19711422</pubmed></ref>
{| class="prettytable" width=100%
|-
|-bgcolor="F5FAFF"
! colspan=3 | [[Week 5]] ({{GA}} Clinical Week 7)
|-bgcolor="#AFEEEE"
| <center>'''Day'''</center>
| <center>'''Day'''</center>
| <center>'''Stage'''</center>
| <center>'''Stage'''</center>
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| <center>29</center>
| <center>29</center>
|  
|  
| [[Endocrine_-_Pituitary_Development|Pituitary]] Week 5  elongation, contacts infundibulum, diverticulum of diencephalon  
| {{pituitary}} Week 5  elongation, contacts infundibulum, diverticulum of diencephalon  


[[Cardiovascular System Development|Heart]] Week 5 septation starts, atrial and ventricular  
{{heart}} Week 5 septation starts, atrial and ventricular  


[[Respiratory_System_Development|Respiratory]] Week 5 left and right lung buds push into the pericardioperitoneal canals (primordia of pleural cavity)  
{{respiratory}} Week 5 left and right lung buds push into the pericardioperitoneal canals (primordia of pleural cavity)  


[[Respiratory_System_Development|Respiratory]]  Week 5 to 17 lung histology - pseudoglandular  
[[Respiratory_System_Development|Respiratory]]  Week 5 to 17 lung histology - pseudoglandular  


[[Sensory_-_Hearing_and_Balance_Development|Hearing]] Week 5 cochlear part of otic vesicle elongates (humans 2.5 turns)  
{{hearing}} Week 5 cochlear part of otic vesicle elongates (humans 2.5 turns)  


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>30</center>
| <center>30</center>
| &nbsp;
| &nbsp;
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| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>32</center>
| <center>32</center>
| [[Carnegie stage 14|Stage 14]]
| [[Carnegie stage 14|Stage 14]]
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[[Musculoskeletal_System_-_Limb_Development|Limb]] upper and lower limb buds growing.
[[Musculoskeletal_System_-_Limb_Development|Limb]] upper and lower limb buds growing.


[[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] mesoderm of the primary body wall coalesced in the ventral midline to create the abdominal cavity.<ref name=PMID22976993><pubmed>22976993</pubmed>| [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3976953 PMC3976953] | [http://dx.doi.org/10.1002/ar.22556 Anat Rec (Hoboken)]</ref>
[[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] mesoderm of the primary body wall coalesced in the ventral midline to create the abdominal cavity.{{#pmid:22976993|PMID22976993}}


[[Neural System Development|Neural]] first appearance of the future cerebral hemispheres. Cerebellar plate differentiated to an intermediate layer, and future rhombic lip identifiable<ref name="PMID3377191"><pubmed>3377191</pubmed></ref>
{{neural}} first appearance of the future cerebral hemispheres. Cerebellar plate differentiated to an intermediate layer, and future rhombic lip identifiable{{#pmid:3377191|PMID3377191}}


[[Neural - Vascular Development]] - basilar artery forms from the consolidation of the neural arteries.<ref name="PMID26060802"><pubmed>26060802</pubmed>| [http://synapse.koreamed.org/DOIx.php?id=10.5853/jos.2015.17.2.144 J Stroke.]</ref>
[[Neural - Vascular Development]] - basilar artery forms from the consolidation of the neural arteries.{{#pmid:26060802|PMID26060802}}


[[Neural_-_Ventricular_System_Development|Ventricular System]] Subarachnoid space initially as irregular spaces on the ventral surface of the spinal cord. 16228957
[[Neural_-_Ventricular_System_Development|Ventricular System]] Subarachnoid space initially as irregular spaces on the ventral surface of the spinal cord.{{#pmid:16228957|PMID16228957}}


[[Gastrointestinal_Tract_-_Liver_Development|Liver]] hepatic gland and its vascular channels enlarge, hematopoietic function appears<ref name="PMID9407542" />
[[Gastrointestinal_Tract_-_Liver_Development|Liver]] hepatic gland and its vascular channels enlarge, hematopoietic function appears{{#pmid:9407542|PMID9407542}}


[[Vision_-_Lens_Development|Eye - Lens]] the lens placode is indented by the lens pit.<ref name="PMID7364662"><pubmed>7364662</pubmed></ref>
[[Vision_-_Lens_Development|Eye - Lens]] the lens placode is indented by the lens pit.{{#pmid:7364662|PMID7364662}}


|-
|-
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| [[File:Stage15_bf1c.jpg|90px|link=Carnegie_stage_15]]  
| [[File:Stage15_bf1c.jpg|90px|link=Carnegie_stage_15]]  


[[Neural System Development|Neural]] cranial nerves (except olfactory and optic) are identifiable in more advanced embryos<ref name="PMID3213956"><pubmed>3213956</pubmed></ref>
{{neural}} cranial nerves (except olfactory and optic) are identifiable in more advanced embryos{{#pmid:3213956|PMID3213956}}


[[Neural - Vascular Development]] - vertebral arteries form from transverse anastomoses between cervical intersegmental arteries, beginning with the proatlantal artery and proceeding downward to the 6th intersegmental artery,<ref name="PMID26060802"><pubmed>26060802</pubmed>| [http://synapse.koreamed.org/DOIx.php?id=10.5853/jos.2015.17.2.144 J Stroke.]</ref>
[[Neural - Vascular Development]] - vertebral arteries form from transverse anastomoses between cervical intersegmental arteries, beginning with the proatlantal artery and proceeding downward to the 6th intersegmental artery,{{#pmid:26060802|PMID26060802}}


[[Vision_-_Lens_Development|Eye - Lens]] the lens pit is closed. The lens vesicle and optic cup lie close to the surface ectoderm and appear to press against the surface.<ref name="PMID7364662"><pubmed>7364662</pubmed></ref>
[[Vision_-_Lens_Development|Eye - Lens]] the lens pit is closed. The lens vesicle and optic cup lie close to the surface ectoderm and appear to press against the surface.{{#pmid:7364662|PMID7364662}}


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>34</center>
| <center>34</center>
|  
|  
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| &nbsp;
| &nbsp;
| [[Sensory_-_Vision_Development|Vision]] 35 to 37 days retinal pigment present  
| [[Sensory_-_Vision_Development|Vision]] 35 to 37 days retinal pigment present  
|-
 
! colspan=3 | [[Week 6]] ({{GA}} Clinical Week 8)  
|}
|-bgcolor="#AFEEEE"
 
== Week 6 ==
[[Week 6]] ({{GA}} Clinical Week 8)  
 
 
{| class="prettytable" width=100%
|-bgcolor="F5FAFF"
| <center>'''Day'''</center>
| <center>'''Day'''</center>
| <center>'''Stage'''</center>
| <center>'''Stage'''</center>
Line 318: Line 443:
[[Tongue_Development|Tongue]]  Week 6 - descent of heart and lungs into thorax. Pleuroperitoneal foramen closes gustatory papilla, caudal midline near the foramen caecum (week 6 to 7 - nerve fibers approach the lingual epithelium)  
[[Tongue_Development|Tongue]]  Week 6 - descent of heart and lungs into thorax. Pleuroperitoneal foramen closes gustatory papilla, caudal midline near the foramen caecum (week 6 to 7 - nerve fibers approach the lingual epithelium)  


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>37</center>
| <center>37</center>
| [[Carnegie stage 16|Stage 16]]
| [[Carnegie stage 16|Stage 16]]
| [[File:Stage16_bf1c.jpg|90px|link=Carnegie_stage_16]] [[Neural System Development|Neural]] first parasympathetic ganglia, submandibular and ciliary, are identifiable<ref name="PMID2751117"><pubmed>2751117</pubmed></ref>
| [[File:Stage16_bf1c.jpg|90px|link=Carnegie_stage_16]] [[Neural System Development|Neural]] first parasympathetic ganglia, submandibular and ciliary, are identifiable{{#pmid:2751117|PMID2751117}}


[[Neural - Vascular Development]] -  development of the middle cerebral artery is first identified as small buds originating proximal to the anterior cerebral artery on the anterior division of the primitive internal carotid artery.<ref name="PMID26060802"><pubmed>26060802</pubmed>| [http://synapse.koreamed.org/DOIx.php?id=10.5853/jos.2015.17.2.144 J Stroke.]</ref>
[[Neural - Vascular Development]] -  development of the middle cerebral artery is first identified as small buds originating proximal to the anterior cerebral artery on the anterior division of the primitive internal carotid artery.{{#pmid:26060802|PMID26060802}}


[[Musculoskeletal_System_-_Limb_Development|Limb]] upper limb bud '''nerves''' median nerve, radial nerve and ulnar nerve entered into hand plate, '''myoblasts''' spindle shaped and oriented parallel to limb bud axis.
[[Musculoskeletal_System_-_Limb_Development|Limb]] upper limb bud '''nerves''' median nerve, radial nerve and ulnar nerve entered into hand plate, '''myoblasts''' spindle shaped and oriented parallel to limb bud axis.


[[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] muscle cell migration about 25% of the hemicircumference of the abdominal cavity, the lateral plate mesoderm has become more condensed and thicker in the area around the myoblasts.<ref name="PMID22976993" />
[[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] muscle cell migration about 25% of the hemicircumference of the abdominal cavity, the lateral plate mesoderm has become more condensed and thicker in the area around the myoblasts.{{#pmid:22976993|PMID22976993}}


[[Cardiovascular System Development|Heart]]  outflow tract elliptical configuration with four cushions, the two larger fusing at this stage. Semilunar valve leaflets form at the downstream end of the cushions
[[Cardiovascular System Development|Heart]]  outflow tract elliptical configuration with four cushions, the two larger fusing at this stage. Semilunar valve leaflets form at the downstream end of the cushions
Line 333: Line 458:
[[Head_Development|Head]] lip and palate components of the upper lip, medial nasal prominence and maxillary process present, median palatine process appears.
[[Head_Development|Head]] lip and palate components of the upper lip, medial nasal prominence and maxillary process present, median palatine process appears.


[[Integumentary_System_-_Eyelid_Development|Eyelid]] prior to the development of the eyelids, one small sulcus or groove forms above the eye (eyelid groove) and another below it.<ref name="PMID7364662"><pubmed>7364662</pubmed></ref>
[[Integumentary_System_-_Eyelid_Development|Eyelid]] prior to the development of the eyelids, one small sulcus or groove forms above the eye (eyelid groove) and another below it.{{#pmid:7364662|PMID7364662}}


|-
|-
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| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>39</center>
| <center>39</center>
| &nbsp;
| &nbsp;
Line 350: Line 475:
| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>41</center>
| <center>41</center>
| [[Carnegie stage 17|Stage 17]]
| [[Carnegie stage 17|Stage 17]]
|  [[File:Stage17_bf1c.jpg|90px|link=Carnegie_stage_17]]  
|  [[File:Stage17_bf1c.jpg|90px|link=Carnegie_stage_17]]  


* [[Neural System Development|Neural]]
* {{neural}}
** telencephalon areas of the future archicortex, paleocortex, and neocortex, visible. Beginning of future choroid plexus<ref name="PMID2802187"><pubmed>2802187</pubmed></ref>
** telencephalon areas of the future archicortex, paleocortex, and neocortex, visible. Beginning of future choroid plexus{{#pmid:2802187|PMID2802187}}
** primordium of the epidural space appears first on the ventral part of the vertebral canal and develops rostro-caudally<ref name="PMID15478101"><pubmed>15478101</pubmed></ref>
** primordium of the epidural space appears first on the ventral part of the vertebral canal and develops rostro-caudally{{#pmid:15478101|PMID15478101}}
* [[Sensory_-_Smell_Development|Smell]] olfactory nerve fibres enter the brain<ref name="PMID15604533"><pubmed>15604533</pubmed></ref>
* [[Sensory_-_Smell_Development|Smell]] olfactory nerve fibres enter the brain{{#pmid:15604533|PMID15604533}}
* [[Integumentary_System_-_Eyelid_Development|Eyelid]] sulcus (groove) above and below eye deepen and eyelid folds develop (below first and then above)<ref name="PMID7364662"><pubmed>7364662</pubmed></ref>
* [[Integumentary_System_-_Eyelid_Development|Eyelid]] sulcus (groove) above and below eye deepen and eyelid folds develop (below first and then above){{#pmid:7364662|PMID7364662}}
* [[Respiratory_System_-_Diaphragm|Diaphragm]] - pleuroperitoneal fold (PPF) no longer separated from the diaphragm (CRL 14mm)<ref name=PMID19711422><pubmed>19711422</pubmed></ref>
* [[Respiratory_System_-_Diaphragm|Diaphragm]] - pleuroperitoneal fold (PPF) no longer separated from the diaphragm (CRL 14mm){{#pmid:19711422|PMID19711422}}
* [[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] muscle cells now migrated approximately 50% of the distance to the ventral midline, inner and outer layers were not discernible yet.<ref name="PMID22976993" />
* [[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] muscle cells now migrated approximately 50% of the distance to the ventral midline, inner and outer layers were not discernible yet.<ref name="PMID22976993" />
|-
|-
Line 367: Line 492:
| [[Cardiovascular System Development|Heart]]  separation of common cardiac outflow (aortic arch and pulmonary aorta)
| [[Cardiovascular System Development|Heart]]  separation of common cardiac outflow (aortic arch and pulmonary aorta)


|-
|}
! colspan=3 | [[Week 7]] ({{GA}} Clinical Week 9)  
 
|-bgcolor="#AFEEEE"
== Week 7 ==
[[Week 7]] ({{GA}} Clinical Week 9)  
 
 
{| class="prettytable" width=100%
|-bgcolor="F5FAFF"
| <center>'''Day'''</center>
| <center>'''Day'''</center>
| <center>'''Stage'''</center>
| <center>'''Stage'''</center>
Line 381: Line 511:
[[Respiratory_System_Development|Respiratory]]  Week 7 - enlargement of liver stops descent of heart and lungs
[[Respiratory_System_Development|Respiratory]]  Week 7 - enlargement of liver stops descent of heart and lungs


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>44</center>
| <center>44</center>
| [[Carnegie stage 18|Stage 18]]
| [[Carnegie stage 18|Stage 18]]
Line 388: Line 518:
[[Musculoskeletal_System_-_Limb_Development|Limb]] [[Musculoskeletal_System_-_Bone_Development|Bone]] forms by endochondrial ossification and throughout embryo replacement of cartilage with bone (week 5-12).  
[[Musculoskeletal_System_-_Limb_Development|Limb]] [[Musculoskeletal_System_-_Bone_Development|Bone]] forms by endochondrial ossification and throughout embryo replacement of cartilage with bone (week 5-12).  


[[Neural System Development|Neural]] [[Sensory_-_Smell_Development|Smell]] vomeronasal fibres and nervus terminalis<ref name="PMID15604533"><pubmed>15604533</pubmed></ref>
{{neural}} [[Sensory_-_Smell_Development|Smell]] vomeronasal fibres and nervus terminalis{{#pmid:15604533|PMID15604533}}


[[Gastrointestinal_Tract_-_Liver_Development|Liver]] obturation due to epithelial proliferation, bile ducts became reorganized, continuity between liver cells and gut<ref name="PMID9407542" />
[[Gastrointestinal_Tract_-_Liver_Development|Liver]] obturation due to epithelial proliferation, bile ducts became reorganized, continuity between liver cells and gut{{#pmid:9407542|PMID9407542}}


[[Neural_-_Ventricular_System_Development|Ventricular System]] duramater appears and spaces surround the circumference of the spinal cord, which coalesce and contain many blood vessels.<ref name="PMID15478101"><pubmed>15478101</pubmed></ref>
[[Neural_-_Ventricular_System_Development|Ventricular System]] duramater appears and spaces surround the circumference of the spinal cord, which coalesce and contain many blood vessels.{{#pmid:15478101|PMID15478101}}


[[Genital - Female Development]] opening of the paramesonephric (Müllerian) duct to the coelomic cavity formed as an invagination of the coelomic epithelium<ref name="PMID12740945"><pubmed>12740945</pubmed></ref>
[[Genital - Female Development]] opening of the paramesonephric (Müllerian) duct to the coelomic cavity formed as an invagination of the coelomic epithelium{{#pmid:12740945|PMID12740945}}


[[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] separation of the myoblasts into distinct inner and outer layers, with unidirectional orientation. Abdominal wall thicker in the region where secondary structures were forming compared with the primary body wall region, dorsally outermost layer of connective tissue approximately half of this thickness.<ref name="PMID22976993" />
[[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] separation of the myoblasts into distinct inner and outer layers, with unidirectional orientation. Abdominal wall thicker in the region where secondary structures were forming compared with the primary body wall region, dorsally outermost layer of connective tissue approximately half of this thickness.{{#pmid:22976993|PMID22976993}}


|-
|-
Line 405: Line 535:
[[Gastrointestinal_Tract_-_Liver_Development|Liver]] (stage 18 to 23)  biliary ductules developed in periportal connective tissue  
[[Gastrointestinal_Tract_-_Liver_Development|Liver]] (stage 18 to 23)  biliary ductules developed in periportal connective tissue  


produces ductal plates that receive biliary capillaries<ref name="PMID9407542" />
produces ductal plates that receive biliary capillaries{{#pmid:9407542|PMID9407542}}


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>46</center>
| <center>46</center>
| &nbsp;
| &nbsp;
Line 417: Line 547:
| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>48</center>
| <center>48</center>
| [[Carnegie stage 19|Stage 19]]
| [[Carnegie stage 19|Stage 19]]
|  [[File:Stage19_bf1c.jpg|90px|link=Carnegie_stage_19]]  
|  [[File:Stage19_bf1c.jpg|90px|link=Carnegie_stage_19]]  


* [[Sensory_-_Vision_Development|Vision]] - (stage 19 -22) [[Integumentary_System_-_Eyelid_Development|eyelid]] folds develop into the eyelids and cover more of the eye as the palpebral fissure takes shape. The upper and the lower eyelids meet at the outer canthus in Stage 19. <ref name=“PMID7364662”><pubmed>7364662</pubmed></ref>
* [[Sensory_-_Vision_Development|Vision]] - (stage 19 -22) [[Integumentary_System_-_Eyelid_Development|eyelid]] folds develop into the eyelids and cover more of the eye as the palpebral fissure takes shape. The upper and the lower eyelids meet at the outer canthus in Stage 19.{{#pmid:7364662|PMID7364662}}
* [[Cardiovascular System Development|Cardiovascular]]  
* [[Cardiovascular System Development|Cardiovascular]]  
** arterial system<ref>{{Ref-KeibelMall1912}}</ref> [[Book - Manual of Human Embryology 18-6|Chapter 18]] [[:File:Keibel Mall 2 390.jpg|fig. 447]]).  
** arterial system<ref name=KeibelMall1912>{{Ref-KeibelMall1912}}</ref> [[Book - Manual of Human Embryology 18-6|Chapter 18]] [[:File:Keibel Mall 2 390.jpg|fig. 447]]).  
** aortic arches <ref>{{Ref-Congdon1922}}</ref> stages 11–19 (figs. 29–40).
** aortic arches <ref name=Congdon1922>{{Ref-Congdon1922}}</ref> stages 11–19 (figs. 29–40).
** [[Cardiovascular System Development|Heart]] fusion of aortic and mitral endocardial cushion material</ref>{{Ref-Teal1986}}</ref>
** [[Cardiovascular System Development|Heart]] fusion of aortic and mitral endocardial cushion material</ref>{{Ref-Teal1986}}</ref>
* [[Respiratory System Development|Respiratory]] - first generation of subsegmental bronchi now complete, see bronchial tree reconstruction<ref>{{Ref-Wells1954}}</ref> (plates 3 and 4).
* [[Respiratory System Development|Respiratory]] - first generation of subsegmental bronchi now complete, see bronchial tree reconstruction<ref name=Wells1954>{{Ref-Wells1954}}</ref> (plates 3 and 4).
* [[Gastrointestinal Tract Development|Gastrointestinal]] - anal membrane defined.
* [[Gastrointestinal Tract Development|Gastrointestinal]] - anal membrane defined.
* [[Renal System Development|Renal]] - Cloacal membrane ruptures from urinary pressure at [[Carnegie stage 18|stage 18]] or [[Carnegie stage 19|stage 19]],  
* [[Renal System Development|Renal]] - Cloacal membrane ruptures from urinary pressure at [[Carnegie stage 18|stage 18]] or [[Carnegie stage 19|stage 19]],  
* [[Genital System Development|Genital]]
* {{genital}}
** Testis - Rete testis develops from the seminiferous cords at stages 19–23, and tunica albuginea forms.<ref>{{Ref-Jirasek1971}}</ref>.  
** {{testis}} - Rete testis develops from the seminiferous cords at stages 19–23, and tunica albuginea forms.<ref name=Jirasek1971>{{Ref-Jirasek1971}}</ref>.  
** Ovary - Rete ovarii cords are developing.<ref>{{Ref-Wilson1926a}}</ref>
** {{ovary}} - Rete ovarii cords are developing.<ref>{{Ref-Wilson1926a}}</ref>
** [[Uterus Development|Uterus]] Müllerian duct grows independently from the invagination of the coelomic epithelium during stages 19-23<ref name="PMID12740945"><pubmed>12740945</pubmed></ref>
** [[Uterus Development|Uterus]] Müllerian duct grows independently from the invagination of the coelomic epithelium during stages 19-23{{#pmid:12740945|PMID12740945}}
* [[Musculoskeletal System Development|Musculoskeletal]]
* [[Musculoskeletal System Development|Musculoskeletal]]
** Sternum right and left sternal bars are present.<ref>{{Ref-Gasser1975}}</ref> (figs. 7-17 and 7-22)
** Sternum right and left sternal bars are present.<ref>{{Ref-Gasser1975}}</ref> (figs. 7-17 and 7-22)
** [[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] segregation of the myoblasts into four distinct muscle groups with unidirectional orientation of myoblasts. Myoblast migrated over half of the distance to the ventral midline, abdominal wall thickest where the muscles migrated and the outermost layer of connective tissue comprises approximately half of the total thickness of the abdominal wall. Rectus muscle completely separated after migrating over half the distance to the midline.<ref name="PMID22976993" />
** [[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] segregation of the myoblasts into four distinct muscle groups with unidirectional orientation of myoblasts. Myoblast migrated over half of the distance to the ventral midline, abdominal wall thickest where the muscles migrated and the outermost layer of connective tissue comprises approximately half of the total thickness of the abdominal wall. Rectus muscle completely separated after migrating over half the distance to the midline.{{#pmid:22976993|PMID22976993}}
* [[Neural System Development|Neural]]
* {{neural}}
** rhombencephalon migration for olivary and arcuate nuclei begins.  
** rhombencephalon migration for olivary and arcuate nuclei begins.  
** choroid plexus of the fourth ventricle present.  
** choroid plexus of the fourth ventricle present.  
** stria medullaris thalami reaches the habenular nuclei.  
** stria medullaris thalami reaches the habenular nuclei.  
** habenular commissure  begins to develop.
** habenular commissure  begins to develop.
** accessory olivary nucleus appears<ref name="PMID2268071"><pubmed>2268071</pubmed></ref>
** accessory olivary nucleus appears{{#pmid:2268071|PMID2268071}}
** [[Neural - Vascular Development]] - middle cerebral artery becomes more prominent, the plexi fuse into a single artery and further branches pierce the cerebral hemisphere.<ref name="PMID26060802"><pubmed>26060802</pubmed>| [http://synapse.koreamed.org/DOIx.php?id=10.5853/jos.2015.17.2.144 J Stroke.]</ref>
** [[Neural - Vascular Development]] - middle cerebral artery becomes more prominent, the plexi fuse into a single artery and further branches pierce the cerebral hemisphere.{{#pmid:26060802|PMID26060802}}
|-
|-
| <center>49</center>
| <center>49</center>
Line 449: Line 579:
| &nbsp;
| &nbsp;


|-
|}
! colspan=3 | [[Week 8]] ({{GA}} Clinical Week 10)  
 
|-bgcolor="#AFEEEE"
== Week 8 ==
[[Week 8]] ({{GA}} Clinical Week 10)  
 
 
{| class="prettytable" width=100%
|-bgcolor="F5FAFF"
| <center>'''Day'''</center>
| <center>'''Day'''</center>
| <center>'''Stage'''</center>
| <center>'''Stage'''</center>
Line 465: Line 600:
[[Musculoskeletal_System_-_Limb_Development|Limb]]  upper limbs begin to rotate ventrally  
[[Musculoskeletal_System_-_Limb_Development|Limb]]  upper limbs begin to rotate ventrally  


[[Neural System Development|Neural]] amygdaloid body has at least four individual nuclei<ref name="PMID2268071"><pubmed>2268071</pubmed></ref>
[[Neural System Development|Neural]] amygdaloid body has at least four individual nuclei{{#pmid:2268071|PMID2268071}}


oculomotor nerve shows a dorsolateral and a ventromedial portion  
oculomotor nerve shows a dorsolateral and a ventromedial portion  
Line 475: Line 610:
choroid plexuses of the fourth and lateral ventricles  
choroid plexuses of the fourth and lateral ventricles  


[[Integumentary_System_-_Eyelid_Development|Eyelid]]  the inner canthus is established.<ref name="PMID7364662"><pubmed>7364662</pubmed></ref>
[[Integumentary_System_-_Eyelid_Development|Eyelid]]  the inner canthus is established.{{#pmid:7364662|PMID7364662}}


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>51</center>
| <center>51</center>
| &nbsp;
| &nbsp;
Line 487: Line 622:
|  [[File:Stage21_bf1c.jpg|90px|link=Carnegie_stage_21]]
|  [[File:Stage21_bf1c.jpg|90px|link=Carnegie_stage_21]]


[[Neural System Development|Neural]] cortical plate appears in the area of future insula<ref name="PMID2252222"><pubmed>2252222</pubmed></ref>
{{neural}} cortical plate appears in the area of future insula{{#pmid:2252222|PMID2252222}}


[[Neural - Vascular Development]] - formation of the anterior communicating artery.<ref name="PMID26060802"><pubmed>26060802</pubmed>| [http://synapse.koreamed.org/DOIx.php?id=10.5853/jos.2015.17.2.144 J Stroke.]</ref>
[[Neural - Vascular Development]] - formation of the anterior communicating artery.{{#pmid:26060802|PMID26060802}}


[[Musculoskeletal_System_-_Limb_Development|Limb]] upper and lower limbs rotate  
[[Musculoskeletal_System_-_Limb_Development|Limb]] upper and lower limbs rotate  
Line 495: Line 630:
[[Coelomic Cavity Development|Intraembryonic Coelom]]  pericardioperitoneal canals close  
[[Coelomic Cavity Development|Intraembryonic Coelom]]  pericardioperitoneal canals close  


[[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] Myoblasts have reached the ventral midline and myotubes were present and oriented uniformly within all muscle groups. The rectus abdominis formed distinct bundles of muscle. Connective tissue layers comprised the majority of the thickness of the abdominal wall, outermost layer of connective tissue accounted for the majority of this thickness.<ref name="PMID22976993" />
[[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] Myoblasts have reached the ventral midline and myotubes were present and oriented uniformly within all muscle groups. The rectus abdominis formed distinct bundles of muscle. Connective tissue layers comprised the majority of the thickness of the abdominal wall, outermost layer of connective tissue accounted for the majority of this thickness.{{#pmid:22976993|PMID22976993}}
|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>53</center>
| <center>53</center>
| &nbsp;
| &nbsp;
Line 504: Line 639:
| <center>54</center>
| <center>54</center>
| [[Carnegie stage 22|Stage 22]]
| [[Carnegie stage 22|Stage 22]]
|  [[File:Stage22_bf1c.jpg|90px|link=Carnegie_stage_22]] [[Neural System Development|Neural]] neocortical fibres project to epithalamus, to dorsal thalamus, and to mesencephalon<ref name="PMID2252222" />
|  [[File:Stage22_bf1c.jpg|90px|link=Carnegie_stage_22]] {{neural}} neocortical fibres project to epithalamus, to dorsal thalamus, and to mesencephalon{{#pmid:2252222|PMID2252222}}


[[Musculoskeletal_System_-_Limb_Development|Limb]] fingers and toes lengthen
[[Musculoskeletal_System_-_Limb_Development|Limb]] fingers and toes lengthen


[[Sensory_-_Smell_Development|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>
[[Sensory_-_Smell_Development|Smell]] Stage 22 to early fetal period - migratory streams of neurons from the subventricular zone of the olfactory bulb towards the future claustrum{{#pmid:15604533|PMID15604533}}


[[Uterus Development|Uterus]]  [[Vagina Development|Vagina]] fused duct (uterovaginal canal) bifurcated at the caudal portion at Carnegie stages 22 and 23<ref name="PMID12740945"><pubmed>12740945</pubmed></ref>
[[Uterus Development|Uterus]]  [[Vagina Development|Vagina]] fused duct (uterovaginal canal) bifurcated at the caudal portion at Carnegie stages 22 and 23{{#pmid:12740945|PMID12740945}}


|-
|-


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>55</center>
| <center>55</center>
|  
|  
Line 521: Line 656:
[[Genital_System_Development|Genital]] 8 to 12 Weeks - hCG stimulates testosterone production  
[[Genital_System_Development|Genital]] 8 to 12 Weeks - hCG stimulates testosterone production  


[[Tongue_Development|Tongue]] Week 8 - nerves penetrate epitheilai basal lamina and synapse with undifferentiated, elongated, epithelial cells (taste bud progenitor cell)<ref name="PMID8955790"><pubmed>8955790</pubmed></ref>
[[Tongue_Development|Tongue]] Week 8 - nerves penetrate epitheilai basal lamina and synapse with undifferentiated, elongated, epithelial cells (taste bud progenitor cell){{#pmid:8955790|PMID8955790}}


|-
|-
Line 538: Line 673:
[[Coelomic_Cavity_Development|Extraembryonic Coelom]]  chorionic cavity is now lost by fusion with the expanding amniotic cavity
[[Coelomic_Cavity_Development|Extraembryonic Coelom]]  chorionic cavity is now lost by fusion with the expanding amniotic cavity


[[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>
{{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{{#pmid:2244584|PMID2244584}}


[[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>
[[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){{#pmid:7216919|PMID7216919}}


[[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] Rectus muscle forms 2 or 3 distinct layers with myotube orientation uniform in all muscles. The external oblique and internal oblique started to expand in thickness, transversus a thin layer of muscle.<ref name="PMID22976993" />
[[Musculoskeletal_System_-_Muscle_Development_Timeline#Abdominal_Wall|Abdominal Wall]] Rectus muscle forms 2 or 3 distinct layers with myotube orientation uniform in all muscles. The external oblique and internal oblique started to expand in thickness, transversus a thin layer of muscle.{{#pmid:22976993|PMID22976993}}
|-
|-
| <center>&nbsp;</center>
| <center>&nbsp;</center>
| [[Week 8]]
| [[Week 8]]
| [[Gastrointestinal_Tract_-_Stomach_Development| 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.
[[Genital - Female Development]] paired paramesonephric (Müllerian) ducts contact each other and are fused into a single tube that separates again and returns to the mesonephric (Wolffian) ducts. The paramesonephric ducts have not yet reached the urogenital sinus.{{#pmid:12740945|PMID12740945}}
|}
== Week 9  ==
({{GA}} Clinical Week 11)




[[Genital - Female Development]] paired paramesonephric (Müllerian) ducts contact each other and are fused into a single tube that separates again and returns to the mesonephric (Wolffian) ducts. The paramesonephric ducts have not yet reached the urogenital sinus.<ref name="PMID12740945"><pubmed>12740945</pubmed></ref>
{| class="prettytable" width=100%
|-
|-bgcolor="F5FAFF"
! colspan=3 | Week 9 ({{GA}} Clinical Week 11)
|-bgcolor="#AFEEEE"
| <center>'''Day'''</center>
| <center>'''Day'''</center>
| <center>'''Stage'''</center>
| <center>'''Stage'''</center>
Line 562: Line 701:
| [[File:Size comparison embryo-fetus actual.jpg|90px|link=Fetal Development]]  
| [[File:Size comparison embryo-fetus actual.jpg|90px|link=Fetal Development]]  


[[Sensory_-_Hearing_and_Balance_Development|Hearing]] Week 9 - mesenchyme surrounding membranous labrynth (otic capsule) chondrifies  
{{hearing}} Week 9 - mesenchyme surrounding membranous labrynth (otic capsule) chondrifies  


[[Sensory_-_Smell_Development|Smell]] Embryonic/Fetal transition - localized incomplete lamination of the olfactory bulb<ref name="PMID15604533"><pubmed>15604533</pubmed></ref>
{{smell}} Embryonic/Fetal transition - localized incomplete lamination of the olfactory bulb{{#pmid:15604533|PMID15604533}}


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
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| &nbsp;
| &nbsp;
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| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>60</center>
| <center>60</center>
| &nbsp;
| &nbsp;
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| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>62</center>
| <center>62</center>
| &nbsp;
| &nbsp;
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| Week 9 - CRL 43 mm, femur length 6 mm
| Week 9 - CRL 43 mm, femur length 6 mm


9 weeks CRL 50 mm - [[Genital_System_Development|Genital]] genitalia in both sexes look identical<ref name="PMID17875485"><pubmed>17875485</pubmed></ref>
9 weeks CRL 50 mm - {{genital}} genitalia in both sexes look identical{{#pmid:17875485|PMID17875485}}


uterus - paramesonephric ducts come into apposition with the urorectal septum and begin to fuse
uterus - paramesonephric ducts come into apposition with the urorectal septum and begin to fuse


|-
|}
! colspan=3 | Week 10 ({{GA}} Clinical Week 12)  
 
|-bgcolor="#AFEEEE"
== Week 10 ==
({{GA}} Clinical Week 12)  
 
 
{| class="prettytable" width=100%
|-bgcolor="F5FAFF"
| <center>'''Day'''</center>
| <center>'''Day'''</center>
| <center>'''Stage'''</center>
| <center>'''Stage'''</center>
Line 624: Line 768:
[[Integumentary_System_-_Nail_Development|Nail Development]] fingernails appear
[[Integumentary_System_-_Nail_Development|Nail Development]] fingernails appear


[[Hearing_-_Outer_Ear_Development|Hearing - Outer Ear Development]] Week 10 - Meatal plug extends in a disc-like fashion, the meatus is boot-shaped with a narrow neck and the sole of the meatal plug spreading widely to form the future tympanic membrane medially. Proximal portion of the neck starts to be resorbed.
{{outer ear}} Week 10 - Meatal plug extends in a disc-like fashion, the meatus is boot-shaped with a narrow neck and the sole of the meatal plug spreading widely to form the future tympanic membrane medially. Proximal portion of the neck starts to be resorbed.


[[Hearing - Inner Ear Development|Hearing - Inner Ear Development]] Week 10 - neural-crest-derived melanocytes migrate into the cochlea. They penetrate the basement membrane of the lateral wall epithelium and develop into the intermediate cells of the stria vascularis.<ref name="PMID25663387"><pubmed>25663387</pubmed></ref>
{{inner ear}} Week 10 - neural-crest-derived melanocytes migrate into the cochlea. They penetrate the basement membrane of the lateral wall epithelium and develop into the intermediate cells of the stria vascularis.{{#pmid:25663387|PMID25663387}}
|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>65</center>
| <center>65</center>
| &nbsp;
| &nbsp;
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| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>67</center>
| <center>67</center>
| &nbsp;
| &nbsp;
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| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>69</center>
| <center>69</center>
| &nbsp;
| &nbsp;
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|  
|  
| Week 10 - CRL 55 mm, femur length 9 mm, biparietal diameter 17 mm  
| Week 10 - CRL 55 mm, femur length 9 mm, biparietal diameter 17 mm  
|-
 
! colspan=3 | Week 11 ({{GA}} Clinical Week 13)  
|}
|-bgcolor="#AFEEEE"
 
== Week 11 ==
({{GA}} Clinical Week 13)  
 
 
{| class="prettytable" width=100%
|-bgcolor="F5FAFF"
| <center>'''Day'''</center>
| <center>'''Day'''</center>
| <center>'''Stage'''</center>
| <center>'''Stage'''</center>
| '''Event'''
| '''Event'''


[[Neural_System_Development|Neural]] - [[Neural - Cerebrum Development|Cerebrum]] appearance of the first sulcus (week 11-15, {{GA}} 13-17 weeks)<ref name="PMID17962979"><pubmed>17962979</pubmed></ref>
{{neural}} - [[Neural - Cerebrum Development|Cerebrum]] appearance of the first sulcus (week 11-15, {{GA}} 13-17 weeks){{#pmid:17962979|PMID17962979}}
|-
|-
| <center>71</center>
| <center>71</center>
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[[Gastrointestinal_Tract_-_Stomach_Development| Stomach]] Week 11 - Serotonin containing cells in both the antrum and the fundus.  
[[Gastrointestinal_Tract_-_Stomach_Development| Stomach]] Week 11 - Serotonin containing cells in both the antrum and the fundus.  


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
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| &nbsp;
| &nbsp;
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| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>74</center>
| <center>74</center>
| &nbsp;
| &nbsp;
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| &nbsp;
| &nbsp;


|-bgcolor="#AFEEEE"
|-bgcolor="F5FAFF"
| <center>76</center>
| <center>76</center>
| &nbsp;
| &nbsp;
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|  
|  
| Week 11 - CRL 68 mm, femur length 12 mm, biparietal diameter 20 mm  
| Week 11 - CRL 68 mm, femur length 12 mm, biparietal diameter 20 mm  
|-
 
| colspan=3|'''References'''
|}
<references/>
|}<noinclude>[[Category:Template]][[Category:Timeline]][[Category:Human Embryo]]</noinclude>

Revision as of 12:51, 12 May 2018

Week -2

(GA Week 1)


Day
Menstrual cycle
Event
1
Menstrual Phase
Menstrual cycle.png

Menstrual Cycle changes: Uterine endometrium (loss), Ovary (Follicle Development)

2
  Human- menstrual uterine endometrium.jpg
3
 
4
   
5
Proliferative Phase Smear- early proliferative.jpgOva41he.jpg Menstrual Cycle changes: Uterine endometrium (proliferation), Ovary (Follicle Development)
6
7
   

Week -1

(GA Week 2)


Day
Menstrual cycle Event
8
Proliferative Phase
9
  Smear- mid-proliferative.jpg Human- mid-proliferative uterine endometrium.jpg Ovary10x.jpg Ova20he.jpg Menstrual Cycle - Mid proliferative
10
   
11
   
12
   
13
  Smear- late-proliferative.jpg Human- late proliferative uterine endometrium.jpg Menstrual cycle.png Menstrual Cycle - Late Proliferative
14
Ovulation

Capacitation

Human ovulation 06.jpg Human oocyte.jpg Follicle 001 icon.jpg

Week 1

Week 1 (GA Clinical Week 3)

Week 1 summary
Day
Stage
Event
1
Secretory Phase

Stage 1

Early zygote.jpg Stage1 size with ruler.jpgSmear- secretory.jpg Human- secretory uterine endometrium.jpg Fertilization, Secretory Phase
2
Stage 2 Stage2.jpg Week1 001 icon.jpg Morula, Blastula
3
  Human-blastocyst-day-3-6-icon.jpg Blastocyst Development
4
Stage 3 CSt3.jpg Blastocyst Hatching (zona pellucida lost)
5
  Smear- late secretory.jpg Human- late secretory uterine endometrium.jpg Late Secretory, Blastocyst (free floating)
6
Stage 4 Adplantation
7
Stage 5 Week2 001 icon.jpgStage5 bf11L.jpg

Week 2

Week 2 (GA Week 4)


Day
Stage
Event
8
Week2 001 icon.jpg Implantation
9
   
10
   
11
   
12
   
13
Stage 6 Stage6 bf03.jpgChorion 001 icon.jpg Chorionic Cavity
14
   

Week 3

Week 3 (GA Week 5)


Day
Stage
Event
15
16
Stage 7 Stage7-bf1.jpg Stage7-sem2.jpg Stage7.jpg
17
   
18
Stage 8 Stage8 human.jpg Neuralplate 001 icon.jpg neural neurogenesis, neural groove and folds are first seen
19
 
Stage8 SEM1.jpg
20
Stage 9 Stage9 bf2c.jpg Stage9 sem1b.jpg Musculoskeletal somitogenesis, first somites form and continue to be added in sequence caudally (1 - 3 somite pairs).

neural the three main divisions of the brain, which are not cerebral vesicles, can be distinguished while the neural groove is still completely open

Neural Crest mesencephalic neural crest is visible[1]

21
  Heart cardiogenesis, week 3 begins as paired heart tubes.

Week 4

Week 4 (GA Week 6)


Day
Stage
Event
22
Stage 10 Stage10 bf2c.jpg Stage10 sem10c.jpg Neuraltube 001 icon.jpg

Neural Crest differentiation at spinal cord level from day 22 until day 26

neural folds begin to fuse near the junction between brain and spinal cord, when Neural Crest cells are arising mainly from the neural ectoderm

Neural Crest trigeminal, facial, and postotic ganglia components visible[1]

Neural Crest migration of vagal level neural crest cells begins (7-10 somite stage)

neural rostral neural tube forms 3 primary brain vesicles (week 4)

Respiratory Week 4 - laryngotracheal groove forms on floor foregut.

23
  Heart begins to beat in Humans by day 22-23, first functioning embryonic organ formed.
24
Stage 11 Stage11 bf2c.jpg

Thyroid thyroid median endodermal thickening in the floor of pharynx

neural rostral (or cephalic) neuropore closes within a few hours; closure is bidirectional, it takes place from the dorsal and terminal lips and may occur in two areas simultaneously. The two lips, however, behave differently.

Ventricular System Optic ventricle appears and the neural groove/tube space is initially filled with amniotic fluid.[2]

25
Stage 12 Stage12 bf2b.jpg Stage12 sem1.jpg

pituitary Week 4 hypophysial pouch, Rathke's pouch, diverticulum from roof

liver septum transversum forming liver stroma and hepatic diverticulum forming hepatic trabeculae[3]

neural caudal neuropore takes a day to close (closure is approximately at future somitic pair 31/sacral vertebra 2)

neural secondary neurulation begins

Ventricular System onset of the ventricular system and separates the ependymal from the amniotic fluid.[2]

neural crest cardiac crest, neural crest from rhombomeres 6 and 7 that migrates to pharyngeal arch 3 and from there the truncus arteriosus[1]

Neural Crest vagal neural crest enter the foregut (20-25 somite stage)

26
   
27
   
28
Stage 13 Stage13 bf1c.jpg Stage13 sem1c.jpg neural the neural tube is normally completely closed, ventricular system now separated from amniotic fluid. Neural crest at spinal level is segregating, and spinal ganglia are in series with the somites. Spinal cord ventral roots beginning to develop.[4]

telencephalon cavity appears

Neural - Vascular Development - hindbrain is supplied by two parallel neural arteries (or channels) that obtain their blood supply from carotid-vertebrobasilar anastomoses given by the pharyngeal arch arteries; trigeminal artery, the otic artery, hypoglossal artery, and the proatlantal artery.[5]

Liver epithelial cord proliferation enmeshing stromal capillaries[3]

Smell Crest comes from the nasal plates[6]

Skin 4 weeks - simple ectoderm epithelium over mesenchyme

Skin 1-3 months ectoderm- germinative (basal) cell repeated division of generates stratified epithelium; mesoderm- differentiates into connective tissue and blood vessels

vision Optic vesicle lies close to the surface ectoderm. The surface ectoderm overlying the optic vesicle, in response to this contact, has thickened to form the lens placode.[7]

Diaphragm - pleuroperitoneal fold (PPF) first discernible in human embryos (CRL 6mm).[8]

Week 5

Week 5 (GA Clinical Week 7)


Day
Stage
Event
29
pituitary Week 5 elongation, contacts infundibulum, diverticulum of diencephalon

heart Week 5 septation starts, atrial and ventricular

respiratory Week 5 left and right lung buds push into the pericardioperitoneal canals (primordia of pleural cavity)

Respiratory Week 5 to 17 lung histology - pseudoglandular

hearing Week 5 cochlear part of otic vesicle elongates (humans 2.5 turns)

30
   
31
   
32
Stage 14 Stage14 bf2l.jpg Stage14 sem1c.jpg Placodes sensory placodes, lens pit, otocyst, nasal placode, primary/secondary vesicles, fourth ventricle of brain

Mesoderm continued segmentation of paraxial mesoderm (somite pairs), heart prominence

Head 1st, 2nd and 3rd pharyngeal arch, forebrain, site of lens placode, site of otic placode, stomodeum

Body - heart, liver, umbilical cord, mesonephric ridge visible externally as bulges.

Limb upper and lower limb buds growing.

Abdominal Wall mesoderm of the primary body wall coalesced in the ventral midline to create the abdominal cavity.[9]

neural first appearance of the future cerebral hemispheres. Cerebellar plate differentiated to an intermediate layer, and future rhombic lip identifiable[10]

Neural - Vascular Development - basilar artery forms from the consolidation of the neural arteries.[5]

Ventricular System Subarachnoid space initially as irregular spaces on the ventral surface of the spinal cord.[11]

Liver hepatic gland and its vascular channels enlarge, hematopoietic function appears[3]

Eye - Lens the lens placode is indented by the lens pit.[7]

33
Stage 15 Stage15 bf1c.jpg

neural cranial nerves (except olfactory and optic) are identifiable in more advanced embryos[12]

Neural - Vascular Development - vertebral arteries form from transverse anastomoses between cervical intersegmental arteries, beginning with the proatlantal artery and proceeding downward to the 6th intersegmental artery,[5]

Eye - Lens the lens pit is closed. The lens vesicle and optic cup lie close to the surface ectoderm and appear to press against the surface.[7]

34
 
35
  Vision 35 to 37 days retinal pigment present

Week 6

Week 6 (GA Clinical Week 8)


Day
Stage
Event
36
Pituitary Week 6 - connecting stalk between pouch and oral cavity degenerates

Parathyroid Week 6 - diverticulum elongate, hollow then solid, dorsal cell proliferation

Thymus Week 6 - diverticulum elongate, hollow then solid, ventral cell proliferation

Adrenal Week 6 - fetal cortex forms from mesothelium adjacent to dorsal mesentery, medulla neural crest cells from adjacent sympathetic ganglia

Respire Week 6 - descent of heart and lungs into thorax. Pleuroperitoneal foramen closes

Tongue Week 6 - descent of heart and lungs into thorax. Pleuroperitoneal foramen closes gustatory papilla, caudal midline near the foramen caecum (week 6 to 7 - nerve fibers approach the lingual epithelium)

37
Stage 16 Stage16 bf1c.jpg Neural first parasympathetic ganglia, submandibular and ciliary, are identifiable[13]

Neural - Vascular Development - development of the middle cerebral artery is first identified as small buds originating proximal to the anterior cerebral artery on the anterior division of the primitive internal carotid artery.[5]

Limb upper limb bud nerves median nerve, radial nerve and ulnar nerve entered into hand plate, myoblasts spindle shaped and oriented parallel to limb bud axis.

Abdominal Wall muscle cell migration about 25% of the hemicircumference of the abdominal cavity, the lateral plate mesoderm has become more condensed and thicker in the area around the myoblasts.[9]

Heart outflow tract elliptical configuration with four cushions, the two larger fusing at this stage. Semilunar valve leaflets form at the downstream end of the cushions

Head lip and palate components of the upper lip, medial nasal prominence and maxillary process present, median palatine process appears.

Eyelid prior to the development of the eyelids, one small sulcus or groove forms above the eye (eyelid groove) and another below it.[7]

38
   
39
   
40
   
41
Stage 17 Stage17 bf1c.jpg
  • neural
    • telencephalon areas of the future archicortex, paleocortex, and neocortex, visible. Beginning of future choroid plexus[14]
    • primordium of the epidural space appears first on the ventral part of the vertebral canal and develops rostro-caudally[15]
  • Smell olfactory nerve fibres enter the brain[6]
  • Eyelid sulcus (groove) above and below eye deepen and eyelid folds develop (below first and then above)[7]
  • Diaphragm - pleuroperitoneal fold (PPF) no longer separated from the diaphragm (CRL 14mm)[8]
  • Abdominal Wall muscle cells now migrated approximately 50% of the distance to the ventral midline, inner and outer layers were not discernible yet.[9]
42
  Heart separation of common cardiac outflow (aortic arch and pulmonary aorta)

Week 7

Week 7 (GA Clinical Week 9)


Day
Stage
Event
43
Pancreas Week 7 to 20 pancreatic hormones secretion increases, small amount maternal insulin

Respiratory Week 7 - enlargement of liver stops descent of heart and lungs

44
Stage 18 Stage18 bf1c.jpg

Limb Bone forms by endochondrial ossification and throughout embryo replacement of cartilage with bone (week 5-12).

neural Smell vomeronasal fibres and nervus terminalis[6]

Liver obturation due to epithelial proliferation, bile ducts became reorganized, continuity between liver cells and gut[3]

Ventricular System duramater appears and spaces surround the circumference of the spinal cord, which coalesce and contain many blood vessels.[15]

Genital - Female Development opening of the paramesonephric (Müllerian) duct to the coelomic cavity formed as an invagination of the coelomic epithelium[16]

Abdominal Wall separation of the myoblasts into distinct inner and outer layers, with unidirectional orientation. Abdominal wall thicker in the region where secondary structures were forming compared with the primary body wall region, dorsally outermost layer of connective tissue approximately half of this thickness.[9]

45
   

Liver (stage 18 to 23) biliary ductules developed in periportal connective tissue

produces ductal plates that receive biliary capillaries[3]

46
   
47
   
48
Stage 19 Stage19 bf1c.jpg
  • Vision - (stage 19 -22) eyelid folds develop into the eyelids and cover more of the eye as the palpebral fissure takes shape. The upper and the lower eyelids meet at the outer canthus in Stage 19.[7]
  • Cardiovascular
    • arterial system[17] Chapter 18 fig. 447).
    • aortic arches [18] stages 11–19 (figs. 29–40).
    • Heart fusion of aortic and mitral endocardial cushion material</ref>Teal SI., Moore GW. and Hutchins GM. Development of aortic and mitral valve continuity in the human embryonic heart. (1986) Amer. J. Anat., 176:447-460.</ref>
  • Respiratory - first generation of subsegmental bronchi now complete, see bronchial tree reconstruction[19] (plates 3 and 4).
  • Gastrointestinal - anal membrane defined.
  • Renal - Cloacal membrane ruptures from urinary pressure at stage 18 or stage 19,
  • genital
    • testis - Rete testis develops from the seminiferous cords at stages 19–23, and tunica albuginea forms.[20].
    • ovary - Rete ovarii cords are developing.[21]
    • Uterus Müllerian duct grows independently from the invagination of the coelomic epithelium during stages 19-23[16]
  • Musculoskeletal
    • Sternum right and left sternal bars are present.[22] (figs. 7-17 and 7-22)
    • Abdominal Wall segregation of the myoblasts into four distinct muscle groups with unidirectional orientation of myoblasts. Myoblast migrated over half of the distance to the ventral midline, abdominal wall thickest where the muscles migrated and the outermost layer of connective tissue comprises approximately half of the total thickness of the abdominal wall. Rectus muscle completely separated after migrating over half the distance to the midline.[9]
  • neural
    • rhombencephalon migration for olivary and arcuate nuclei begins.
    • choroid plexus of the fourth ventricle present.
    • stria medullaris thalami reaches the habenular nuclei.
    • habenular commissure begins to develop.
    • accessory olivary nucleus appears[23]
    • Neural - Vascular Development - middle cerebral artery becomes more prominent, the plexi fuse into a single artery and further branches pierce the cerebral hemisphere.[5]
49
   

Week 8

Week 8 (GA Clinical Week 10)


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[23]

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

Eyelid the inner canthus is established.[7]

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

neural cortical plate appears in the area of future insula[24]

Neural - Vascular Development - formation of the anterior communicating artery.[5]

Limb upper and lower limbs rotate

Intraembryonic Coelom pericardioperitoneal canals close

Abdominal Wall Myoblasts have reached the ventral midline and myotubes were present and oriented uniformly within all muscle groups. The rectus abdominis formed distinct bundles of muscle. Connective tissue layers comprised the majority of the thickness of the abdominal wall, outermost layer of connective tissue accounted for the majority of this thickness.[9]

53
   
54
Stage 22 Stage22 bf1c.jpg neural neocortical fibres project to epithalamus, to dorsal thalamus, and to mesencephalon[24]

Limb fingers and toes lengthen

Smell Stage 22 to early fetal period - migratory streams of neurons from the subventricular zone of the olfactory bulb towards the future claustrum[6]

Uterus Vagina fused duct (uterovaginal canal) bifurcated at the caudal portion at Carnegie stages 22 and 23[16]

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)[25]

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, 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[26]

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)[27]

Abdominal Wall Rectus muscle forms 2 or 3 distinct layers with myotube orientation uniform in all muscles. The external oblique and internal oblique started to expand in thickness, transversus a thin layer of muscle.[9]

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

Genital - Female Development paired paramesonephric (Müllerian) ducts contact each other and are fused into a single tube that separates again and returns to the mesonephric (Wolffian) ducts. The paramesonephric ducts have not yet reached the urogenital sinus.[16]

Week 9

(GA Clinical Week 11)


Day
Stage
Event
57
Fetal Period Size comparison embryo-fetus actual.jpg

hearing Week 9 - mesenchyme surrounding membranous labrynth (otic capsule) chondrifies

smell Embryonic/Fetal transition - localized incomplete lamination of the olfactory bulb[6]

58
   
59
 
60
   
61
 
62
   
63
Week 9 - CRL 43 mm, femur length 6 mm

9 weeks CRL 50 mm - genital genitalia in both sexes look identical[28]

uterus - paramesonephric ducts come into apposition with the urorectal septum and begin to fuse

Week 10

(GA Clinical Week 12)


Day
Stage
Event
64
Size comparison embryo-fetus actual.jpg

Gastrointestinal Tract Week 10 intestines in abdomen

Pituitary growth hormone and ACTH detectable

Pancreas Week 10 glucagon (alpha) differentiate first, somatostatin (delta), insulin (beta) cells differentiate, insulin secretion begins

Tongue Week 10 shallow grooves above the taste bud primordium

Stomach Week 10 - Glucagon containing cells in stomach fundus.

Nail Development fingernails appear

outer ear Week 10 - Meatal plug extends in a disc-like fashion, the meatus is boot-shaped with a narrow neck and the sole of the meatal plug spreading widely to form the future tympanic membrane medially. Proximal portion of the neck starts to be resorbed.

inner ear Week 10 - neural-crest-derived melanocytes migrate into the cochlea. They penetrate the basement membrane of the lateral wall epithelium and develop into the intermediate cells of the stria vascularis.[29]

65
   
66
 
67
   
68
 
69
   
70
Week 10 - CRL 55 mm, femur length 9 mm, biparietal diameter 17 mm

Week 11

(GA Clinical Week 13)


Day
Stage
Event

neural - Cerebrum appearance of the first sulcus (week 11-15, GA 13-17 weeks)[30]

71
Size comparison embryo-fetus actual.jpg

Thyroid colloid appearance in thyroid follicles, iodine and thyroid hormone (TH) synthesis

Stomach Week 11 - Serotonin containing cells in both the antrum and the fundus.

72
   
73
 
74
   
75
 
76
   
77
Week 11 - CRL 68 mm, femur length 12 mm, biparietal diameter 20 mm
  1. 1.0 1.1 1.2 O'Rahilly R & Müller F. (2007). The development of the neural crest in the human. J. Anat. , 211, 335-51. PMID: 17848161 DOI.
  2. 2.0 2.1 O'Rahilly R & Müller F. (1990). Ventricular system and choroid plexuses of the human brain during the embryonic period proper. Am. J. Anat. , 189, 285-302. PMID: 2285038 DOI.
  3. 3.0 3.1 3.2 3.3 3.4 Godlewski G, Gaubert-Cristol R, Rouy S & Prudhomme M. (1997). Liver development in the rat and in man during the embryonic period (Carnegie stages 11-23). Microsc. Res. Tech. , 39, 314-27. PMID: 9407542 <314::AID-JEMT2>3.0.CO;2-H DOI.
  4. Müller F & O'Rahilly R. (1988). The development of the human brain from a closed neural tube at stage 13. Anat. Embryol. , 177, 203-24. PMID: 3354839
  5. 5.0 5.1 5.2 5.3 5.4 5.5 Menshawi K, Mohr JP & Gutierrez J. (2015). A Functional Perspective on the Embryology and Anatomy of the Cerebral Blood Supply. J Stroke , 17, 144-58. PMID: 26060802 DOI.
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