Difference between revisions of "Template:First Trimester Timeline"

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|+ colspan=3|'''First Trimester Timeline''' 
 
|+ colspan=3|'''First Trimester Timeline''' 
 
|-
 
|-
|
+
| colspan=3 bgcolor="F5FFFA"|'''Links:''' {{human timeline}} | {{first trimester timeline}} | {{second trimester timeline}} | {{third trimester timeline}}
| colspan=2|{{human timeline}} | {{first trimester timeline}} | {{second trimester timeline}} | {{third trimester timeline}}
+
|-bgcolor="CEDFF2"  
|-bgcolor="FAF5FF"
 
 
! <center>Gestational Day {{GA}}</center>
 
! <center>Gestational Day {{GA}}</center>
 
! width="100px"|<center>Stage</center>
 
! width="100px"|<center>Stage</center>
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| [[File:Menstrual cycle.png|90px|left|link=Menstrual Cycle]]
 
| [[File:Menstrual cycle.png|90px|left|link=Menstrual Cycle]]
  
{{menstrual cycle}} changes: Uterine endometrium (loss), Ovary (Follicle Development)
+
{{menstrual cycle}} changes: {{uterus}} endometrium (loss), {{ovary}} (follicle development)
  
 
|-bgcolor="F5FAFF"
 
|-bgcolor="F5FAFF"
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| <center>5</center>
 
| <center>5</center>
 
| Proliferative Phase  
 
| 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)
+
| [[File:Smear- early proliferative.jpg|90px|link=Menstrual_Cycle_-_Histology]][[File:Ova41he.jpg|90px|link=Menstrual Cycle]] {{menstrual cycle}} changes: {{uterus}} endometrium (proliferation), {{ovary}} (Follicle Development)
  
 
|-bgcolor="F5FAFF"
 
|-bgcolor="F5FAFF"
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| &nbsp;
 
| &nbsp;
 
| &nbsp;
 
| &nbsp;
|-bgcolor="F5FAFF"
 
| <center>'''Day'''</center>
 
| width="100px"|'''Menstrual cycle'''
 
| '''Event'''
 
 
 
|-
 
|-
 
| <center>8</center>
 
| <center>8</center>
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| <center>9</center>
 
| <center>9</center>
 
| &nbsp;
 
| &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
+
| [[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
  
 
|-
 
|-
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| <center>13</center>
 
| <center>13</center>
 
| &nbsp;
 
| &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  
+
| [[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>
 
| <center>14</center>
| Ovulation  
+
| {{Ovulation}}
  
 
Capacitation
 
Capacitation
 
| [[File:Human_ovulation_06.jpg|90px]] [[Image:Human oocyte.jpg|90px]] [[File:Follicle 001 icon.jpg|90px|link=Ovulation Movie]]
 
| [[File:Human_ovulation_06.jpg|90px]] [[Image:Human oocyte.jpg|90px]] [[File:Follicle 001 icon.jpg|90px|link=Ovulation Movie]]
|-bgcolor="F5FAFF"
+
|-bgcolor="CEDFF2"  
| <center>'''Day'''</center>
+
! <center>Fertilization Day</center>
| width="100px"|<center>'''Stage'''</center>
+
! <center>Stage</center>
| '''Event'''
+
! Event
 
 
 
|-
 
|-
 
| <center>1</center>
 
| <center>1</center>
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[[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}}, {{zygote}}, Secretory Phase  
  
 
|-bgcolor="F5FAFF"
 
|-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
  
 
|-
 
|-
 
| <center>3</center>
 
| <center>3</center>
 
| &nbsp;
 
| &nbsp;
| [[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}}
  
 
|-bgcolor="F5FAFF"
 
|-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)  
  
 
|-
 
|-
 
| <center>5</center>
 
| <center>5</center>
 
| &nbsp;
 
| &nbsp;
| [[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="F5FAFF"
 
|-bgcolor="F5FAFF"
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| [[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]]
|-bgcolor="FAF5FF"
 
! <center>Fertilization Day</center>
 
! <center>Stage</center>
 
! Event
 
 
 
|-
 
|-
 
| <center>8</center>
 
| <center>8</center>
 
|  
 
|  
|  [[File:Week2_001 icon.jpg|90px|link=Implantation_Movie]] [[Implantation]]
+
|  [[File:Week2_001 icon.jpg|90px|link=Implantation_Movie]] {{implantation}}
  
 
|-bgcolor="F5FAFF"
 
|-bgcolor="F5FAFF"
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| <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]] {{gastrulation}}, {{ectoderm}}, {{mesoderm}}, {{endoderm}}
  
 
|-
 
|-
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| <center>21</center>
 
| <center>21</center>
 
| &nbsp;
 
| &nbsp;
| [[Cardiovascular System Development|Heart]] cardiogenesis, week 3 begins as paired heart tubes.
+
| {{heart}} cardiogenesis, week 3 begins as paired heart tubes.
 
|-bgcolor="F5FAFF"
 
|-bgcolor="F5FAFF"
 
| <center>'''Day'''</center>
 
| <center>'''Day'''</center>
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{{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}} Week 4 - laryngotracheal groove forms on floor foregut.
  
 
|-bgcolor="F5FAFF"
 
|-bgcolor="F5FAFF"
 
| <center>23</center>
 
| <center>23</center>
 
| &nbsp;
 
| &nbsp;
| [[Cardiovascular System Development|Heart]] begins to beat in Humans by day 22-23, first functioning embryonic organ formed.
+
| {{heart}} begins to beat in Humans by day 22-23, first functioning embryonic organ formed.
  
 
|-
 
|-
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| [[File:Stage11_bf2c.jpg|90px|link=Carnegie_stage_11]]
 
| [[File:Stage11_bf2c.jpg|90px|link=Carnegie_stage_11]]
  
[[Endocrine_-_Thyroid_Development|Thyroid]] thyroid median endodermal thickening in the floor of pharynx  
+
{{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.  
 
{{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.{{#pmid:2285038|PMID2285038}}
+
{{ventricular}} Optic ventricle appears and the neural groove/tube space is initially filled with amniotic fluid.{{#pmid:2285038|PMID2285038}}
  
 
|-bgcolor="F5FAFF"
 
|-bgcolor="F5FAFF"
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{{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.{{#pmid:2285038|PMID2285038}}
+
{{ventricular}} onset of the ventricular system and separates the ependymal from the amniotic fluid.{{#pmid:2285038|PMID2285038}}
  
 
{{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}} 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}} vagal neural crest enter the foregut (20-25 somite stage)
  
 
|-
 
|-
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[[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}}
 
[[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{{#pmid:9407542|PMID9407542}}
+
{{liver}} epithelial cord proliferation enmeshing stromal capillaries{{#pmid:9407542|PMID9407542}}
  
[[Sensory_-_Smell_Development|Smell]] Crest comes from the nasal plates{{#pmid:15604533|PMID15604533}}
+
{{smell}} Crest comes from the nasal plates{{#pmid:15604533|PMID15604533}}
  
[[Integumentary_System_Development|Skin]] 4 weeks - simple ectoderm epithelium over mesenchyme  
+
{{integumentary}} 4 weeks - simple ectoderm epithelium over mesenchyme  
  
[[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}} 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.{{#pmid:7364662|PMID7364662}}
 
{{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}}
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| [[File:Stage14_bf2l.jpg|90px|link=Carnegie_stage_14]] [[File:Stage14_sem1c.jpg|90px|link=Carnegie_stage_14]] [[Placodes]] sensory placodes, lens pit, otocyst, nasal placode, primary/secondary vesicles, fourth ventricle of brain
 
| [[File:Stage14_bf2l.jpg|90px|link=Carnegie_stage_14]] [[File:Stage14_sem1c.jpg|90px|link=Carnegie_stage_14]] [[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
+
{{somite}} continued segmentation of paraxial mesoderm (somite pairs), heart prominence
  
[[Head_Development|Head]] 1st, 2nd and 3rd pharyngeal arch, forebrain, site of lens placode, site of otic placode, stomodeum
+
{{head}} 1st, 2nd and 3rd pharyngeal arch, forebrain, site of lens placode, site of otic placode, stomodeum
  
'''Body - '''heart, [[Gastrointestinal_Tract_-_Liver_Development|liver]], umbilical cord, mesonephric ridge visible externally as bulges.  
+
'''Body - '''{{heart}}, {{liver}}, umbilical cord, mesonephric ridge visible externally as bulges.  
  
[[Musculoskeletal_System_-_Limb_Development|Limb]] upper and lower limb buds growing.
+
{{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.{{#pmid:22976993|PMID22976993}}
 
[[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}}
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[[Neural - Vascular Development]] - basilar artery forms from the consolidation of the neural arteries.{{#pmid:26060802|PMID26060802}}
 
[[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.{{#pmid:16228957|PMID16228957}}
+
{{ventricular}} 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{{#pmid:9407542|PMID9407542}}
+
{{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.{{#pmid:7364662|PMID7364662}}
+
{{vision}} {{lens}} placode is indented by the lens pit.{{#pmid:7364662|PMID7364662}}
  
 
|-
 
|-
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[[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}}
 
[[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.{{#pmid:7364662|PMID7364662}}
+
{{vision}} {{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="F5FAFF"
 
|-bgcolor="F5FAFF"
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| <center>35</center>
 
| <center>35</center>
 
| &nbsp;
 
| &nbsp;
| [[Sensory_-_Vision_Development|Vision]] 35 to 37 days retinal pigment present  
+
| {{vision}} 35 to 37 days retinal pigment present  
 
|-
 
|-
 
| <center>36</center>
 
| <center>36</center>
 
|  
 
|  
| [[Endocrine_-_Pituitary_Development|Pituitary]] Week 6 - connecting stalk between pouch and oral cavity degenerates  
+
| {{pituitary}} Week 6 - connecting stalk between pouch and oral cavity degenerates  
  
[[Endocrine_-_Parathyroid_Development|Parathyroid]] Week 6 - diverticulum elongate, hollow then solid, dorsal cell proliferation  
+
{{parathyroid}} Week 6 - diverticulum elongate, hollow then solid, dorsal cell proliferation  
  
[[Endocrine_-_Thymus_Development|Thymus]] Week 6 - diverticulum elongate, hollow then solid, ventral cell proliferation  
+
{{thymus}} Week 6 - diverticulum elongate, hollow then solid, ventral cell proliferation  
  
[[Endocrine_-_Adrenal_Development|Adrenal]] Week 6  - fetal cortex forms from mesothelium adjacent to dorsal mesentery, medulla neural crest cells from adjacent sympathetic ganglia  
+
{{adrenal}} Week 6  - fetal cortex forms from mesothelium adjacent to dorsal mesentery, medulla neural crest cells from adjacent sympathetic ganglia  
  
[[Respiratory_System_Development|Respire]] Week 6 - descent of heart and lungs into thorax. Pleuroperitoneal foramen closes  
+
{{respiratory}} Week 6 - descent of {{heart}} and lungs into thorax. Pleuroperitoneal foramen closes  
  
[[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}} Week 6 - gustatory papilla, caudal midline near the foramen caecum (week 6 to 7 - nerve fibers approach the lingual epithelium)  
  
 
|-bgcolor="F5FAFF"
 
|-bgcolor="F5FAFF"
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[[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}}
 
[[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.
+
{{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.{{#pmid:22976993|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
+
{{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_Development|Head]] lip and palate components of the upper lip, medial nasal prominence and maxillary process present, median palatine process appears.
+
{{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.{{#pmid:7364662|PMID7364662}}
 
[[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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* {{neural}}  
 
* {{neural}}  
 
** telencephalon areas of the future archicortex, paleocortex, and neocortex, visible. Beginning of future choroid plexus{{#pmid:2802187|PMID2802187}}
 
** 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{{#pmid:15478101|PMID15478101}}
+
** {{ventricular}} 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{{#pmid:15604533|PMID15604533}}  
+
* {{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){{#pmid:7364662|PMID7364662}}
 
* [[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){{#pmid:19711422|PMID19711422}}
 
* [[Respiratory_System_-_Diaphragm|Diaphragm]] - pleuroperitoneal fold (PPF) no longer separated from the diaphragm (CRL 14mm){{#pmid:19711422|PMID19711422}}
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| <center>42</center>
 
| <center>42</center>
 
| &nbsp;
 
| &nbsp;
| [[Cardiovascular System Development|Heart]] separation of common cardiac outflow (aortic arch and pulmonary aorta)
+
| {{heart}} separation of common cardiac outflow (aortic arch and pulmonary aorta)
  
 
|-bgcolor="F5FAFF"
 
|-bgcolor="F5FAFF"
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| <center>43</center>
 
| <center>43</center>
 
|  
 
|  
| [[Endocrine_-_Pancreas_Development|Pancreas]] Week 7 to 20  pancreatic hormones secretion increases, small amount maternal insulin  
+
| {{pancreas}} Week 7 to 20  pancreatic hormones secretion increases, small amount maternal insulin  
  
[[Respiratory_System_Development|Respiratory]] Week 7 - enlargement of liver stops descent of heart and lungs
+
{{respiratory}} Week 7 - enlargement of {{liver}} stops descent of heart and lungs
  
 
|-bgcolor="F5FAFF"
 
|-bgcolor="F5FAFF"
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| [[File:Stage18_bf1c.jpg|90px|link=Carnegie_stage_18]]  
 
| [[File:Stage18_bf1c.jpg|90px|link=Carnegie_stage_18]]  
  
[[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).  
+
{{limb}} {{bone}} forms by endochondrial ossification and throughout embryo replacement of cartilage with bone (week 5-12).  
  
{{neural}} [[Sensory_-_Smell_Development|Smell]] vomeronasal fibres and nervus terminalis{{#pmid:15604533|PMID15604533}}
+
{{neural}} {{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{{#pmid:9407542|PMID9407542}}
+
{{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.{{#pmid:15478101|PMID15478101}}
+
{{ventricular}} 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{{#pmid:12740945|PMID12740945}}
+
{{female}} {{uterus}} 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.{{#pmid:22976993|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 460: Line 448:
 
| &nbsp;
 
| &nbsp;
  
[[Gastrointestinal_Tract_-_Liver_Development|Liver]] (stage 18 to 23)  biliary ductules developed in periportal connective tissue  
+
{{liver}} (stage 18 to 23)  biliary ductules developed in periportal connective tissue  
  
 
produces ductal plates that receive biliary capillaries{{#pmid:9407542|PMID9407542}}
 
produces ductal plates that receive biliary capillaries{{#pmid:9407542|PMID9407542}}
Line 479: Line 467:
 
|  [[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.{{#pmid:7364662|PMID7364662}}  
+
* {{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}}
 
** 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]]).  
 
** 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 name=Congdon1922>{{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>
+
** {{heart}} fusion of aortic and mitral endocardial cushion material<ref name=Teal1986>{{Ref-Teal1986}}</ref>
 
* [[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).
 
* [[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}} - 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}} - Cloacal membrane ruptures from urinary pressure at [[Carnegie stage 18|stage 18]] or [[Carnegie stage 19|stage 19]],  
 
* {{genital}}
 
* {{genital}}
 
** {{testis}} - Rete testis develops from the seminiferous cords at stages 19–23, and tunica albuginea forms.<ref name=Jirasek1971>{{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{{#pmid:12740945|PMID12740945}}
+
** {{uterus}} Müllerian duct grows independently from the invagination of the coelomic epithelium during stages 19-23{{#pmid:12740945|PMID12740945}}
* [[Musculoskeletal System Development|Musculoskeletal]]
+
* {{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 name=Gasser1975>{{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.{{#pmid:22976993|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}}
 
* {{neural}}
Line 512: Line 500:
 
[[Head_Development|Head]] scalp vascular plexus visible  
 
[[Head_Development|Head]] scalp vascular plexus visible  
  
[[Musculoskeletal_System_-_Limb_Development|Limb]] upper limbs begin to rotate ventrally  
+
{{limb}} upper limbs begin to rotate ventrally  
  
[[Neural System Development|Neural]] amygdaloid body has at least four individual nuclei{{#pmid:2268071|PMID2268071}}  
+
{{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 529: Line 517:
 
| <center>51</center>
 
| <center>51</center>
 
| &nbsp;
 
| &nbsp;
| [[Gastrointestinal Tract Development|Gastrointestinal Tract]] anal membrane perforates
+
| {{gastrointestinal tract}} anal membrane perforates
  
 
|-
 
|-
Line 540: Line 528:
 
[[Neural - Vascular Development]] - formation of the anterior communicating artery.{{#pmid:26060802|PMID26060802}}
 
[[Neural - Vascular Development]] - formation of the anterior communicating artery.{{#pmid:26060802|PMID26060802}}
  
[[Musculoskeletal_System_-_Limb_Development|Limb]] upper and lower limbs rotate  
+
{{limb}} upper and lower limbs rotate  
  
 
[[Coelomic Cavity Development|Intraembryonic Coelom]]  pericardioperitoneal canals close  
 
[[Coelomic Cavity Development|Intraembryonic Coelom]]  pericardioperitoneal canals close  
Line 555: Line 543:
 
|  [[File:Stage22_bf1c.jpg|90px|link=Carnegie_stage_22]] {{neural}}  neocortical fibres project to epithalamus, to dorsal thalamus, and to mesencephalon{{#pmid:2252222|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
+
{{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{{#pmid:15604533|PMID15604533}}
+
{{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{{#pmid:12740945|PMID12740945}}
 
[[Uterus Development|Uterus]]  [[Vagina Development|Vagina]] fused duct (uterovaginal canal) bifurcated at the caudal portion at Carnegie stages 22 and 23{{#pmid:12740945|PMID12740945}}
Line 583: Line 571:
 
'''Body '''- straightening of trunk, umbilical cord, intestines herniated at umbilicus
 
'''Body '''- straightening of trunk, umbilical cord, intestines herniated at umbilicus
  
[[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
+
{{limb}} upper limbs longer and bent at elbow, hands and feet turned inward, foot with separated digits, wrist, hand with separated digits
  
 
[[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
Line 599: Line 587:
 
[[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}}
 
[[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}}
 
|-
 
|-
| <center>57</center>
+
| <center>57-63</center>
| Fetal Period
+
| [[Week 9]]
| [[File:Size comparison embryo-fetus actual.jpg|90px|link=Fetal Development]]  
+
| Beginning of [[Fetal Development]]
 
 
{{hearing}} Week 9 - mesenchyme surrounding membranous labrynth (otic capsule) chondrifies
 
 
 
{{smell}} Embryonic/Fetal transition - localized incomplete lamination of the olfactory bulb{{#pmid:15604533|PMID15604533}}
 
 
 
|-bgcolor="F5FAFF"
 
| <center>58</center>
 
| &nbsp;
 
| &nbsp;
 
 
 
|-
 
| <center>59</center>
 
|
 
| &nbsp;
 
  
|-bgcolor="F5FAFF"
+
{{Streeter-embryo to fetus}}
| <center>60</center>
 
| &nbsp;
 
| &nbsp;
 
  
|-
+
CRL 43 mm, femur length 6 mm
| <center>61</center>
 
|
 
| &nbsp;
 
 
 
|-bgcolor="F5FAFF"
 
| <center>62</center>
 
| &nbsp;
 
| &nbsp;
 
 
 
|-
 
| <center>63</center>
 
|
 
| Week 9 - CRL 43 mm, femur length 6 mm
 
  
 
9 weeks CRL 50 mm - {{genital}} genitalia in both sexes look identical{{#pmid:17875485|PMID17875485}}  
 
9 weeks CRL 50 mm - {{genital}} genitalia in both sexes look identical{{#pmid:17875485|PMID17875485}}  
Line 740: Line 698:
 
| 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  
  
|}|}<noinclude>[[Category:Template]][[Category:Timeline]][[Category:First Trimester]][[Category:Human Embryo]]</noinclude>
+
|-
 +
|
 +
| colspan=2|
 +
{| class="wikitable mw-collapsible mw-collapsed"
 +
! Systems &nbsp;
 +
|-
 +
| '''Systems:''' {{bone timeline}} | {{eye neural crest timeline}} | {{heart abnormality timeline}} | {{hearing EAM timeline}} | {{muscle timeline}} | {{ovary timeline}} | {{placental villi timeline}} | {{shoulder timeline}} | {{smell timeline}} | {{spleen timeline}} | {{ventricular timeline}}
 +
|}
 +
|}<noinclude>[[Category:Template]][[Category:Timeline]][[Category:First Trimester]][[Category:Human Embryo]]</noinclude>

Latest revision as of 02:06, 28 October 2019

First Trimester Timeline 
Links: human timeline | first trimester timeline | second trimester timeline | third trimester timeline
Gestational Day GA
Stage
Event
1
Menstrual Phase
Menstrual cycle.png

menstrual cycle changes: uterus endometrium (loss), ovary (follicle development)

2
  Human- menstrual uterine endometrium.jpg
3
 
4
   
5
Proliferative Phase Smear- early proliferative.jpgOva41he.jpg menstrual cycle changes: uterus endometrium (proliferation), ovary (Follicle Development)
6
7
   
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
Fertilization Day
Stage
Event
1
Secretory Phase

Stage 1

Early zygote.jpg Stage1 size with ruler.jpgSmear- secretory.jpg Human- secretory uterine endometrium.jpg fertilization, zygote, Secretory Phase
2
Stage 2 Stage2.jpg Week1 001 icon.jpg morula, Blastula
3
  Human-blastocyst-day-3-6-icon.jpg blastocyst
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
8
Week2 001 icon.jpg implantation
9
   
10
   
11
   
12
   
13
Stage 6 Stage6 bf03.jpgChorion 001 icon.jpg Chorionic Cavity
14
   
Day
Stage
Event
15
16
Stage 7 Stage7-bf1.jpg Stage7-sem2.jpg Stage7.jpg gastrulation, ectoderm, mesoderm, endoderm
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.
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 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 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]

integumentary 4 weeks - simple ectoderm epithelium over mesenchyme

integumentary 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]

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

somite 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 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]

vision 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]

vision 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
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

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

tongue Week 6 - 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]
    • ventricular 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)
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]

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

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

Female uterus 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
  • Respiratory - first generation of subsegmental bronchi now complete, see bronchial tree reconstruction[20] (plates 3 and 4).
  • gastrointestinal tract - 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.[21].
    • ovary - Rete ovarii cords are developing.[22]
    • 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.[23] (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[24]
    • 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
   
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[24]

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[25]

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[25]

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)[26]

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[27]

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)[28]

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]

57-63
Week 9 Beginning of Fetal Development


Historic Embryology
Embryology History George Streeter In 1949 the embryologist George Streeter[29] used the replacement of cartilage within the humerus by bone marrow as an arbitrary definition of the embryo to fetus transition.
"If the onset can be recognized in a given specimen, that specimen is straightway classed as a fetus."


CRL 43 mm, femur length 6 mm

9 weeks CRL 50 mm - genital genitalia in both sexes look identical[30]

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

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.[31]

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

neural - Cerebrum appearance of the first sulcus (week 11-15, GA 13-17 weeks)[32]

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
Systems  
Systems: bone timeline | eye neural crest timeline | heart abnormality timeline | hearing EAM timeline | muscle timeline | ovary timeline | placental villi timeline | shoulder timeline | smell timeline | spleen timeline | ventricular timeline
  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.
  6. 6.0 6.1 6.2 6.3 Müller F & O'Rahilly R. (2004). Olfactory structures in staged human embryos. Cells Tissues Organs (Print) , 178, 93-116. PMID: 15604533 DOI.
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 Pearson AA. (1980). The development of the eyelids. Part I. External features. J. Anat. , 130, 33-42. PMID: 7364662
  8. 8.0 8.1 Clugston RD, Zhang W & Greer JJ. (2010). Early development of the primordial mammalian diaphragm and cellular mechanisms of nitrofen-induced congenital diaphragmatic hernia. Birth Defects Res. Part A Clin. Mol. Teratol. , 88, 15-24. PMID: 19711422 DOI.
  9. 9.0 9.1 9.2 9.3 9.4 9.5 9.6 Nichol PF, Corliss RF, Yamada S, Shiota K & Saijoh Y. (2012). Muscle patterning in mouse and human abdominal wall development and omphalocele specimens of humans. Anat Rec (Hoboken) , 295, 2129-40. PMID: 22976993 DOI.
  10. Müller F & O'Rahilly R. (1988). The first appearance of the future cerebral hemispheres in the human embryo at stage 14. Anat. Embryol. , 177, 495-511. PMID: 3377191
  11. Patelska-Banaszewska M & Woźniak W. (2005). The subarachnoid space develops early in the human embryonic period. Folia Morphol. (Warsz) , 64, 212-6. PMID: 16228957
  12. Müller F & O'Rahilly R. (1988). The development of the human brain, including the longitudinal zoning in the diencephalon at stage 15. Anat. Embryol. , 179, 55-71. PMID: 3213956
  13. Müller F & O'Rahilly R. (1989). The human brain at stage 16, including the initial evagination of the neurohypophysis. Anat. Embryol. , 179, 551-69. PMID: 2751117
  14. Müller F & O'Rahilly R. (1989). The human brain at stage 17, including the appearance of the future olfactory bulb and the first amygdaloid nuclei. Anat. Embryol. , 180, 353-69. PMID: 2802187
  15. 15.0 15.1 Patelska-Banaszewska M & Woźniak W. (2004). The development of the epidural space in human embryos. Folia Morphol. (Warsz) , 63, 273-9. PMID: 15478101
  16. 16.0 16.1 16.2 16.3 Hashimoto R. (2003). Development of the human Müllerian duct in the sexually undifferentiated stage. Anat Rec A Discov Mol Cell Evol Biol , 272, 514-9. PMID: 12740945 DOI.
  17. Keibel F. and Mall FP. Manual of Human Embryology II. (1912) J. B. Lippincott Company, Philadelphia.
  18. Congdon ED. Transformation of the aortic-arch system during the development of the human embryo. (1922) Contrib. Embryol., Carnegie Inst. Wash. Publ 277, 14:47-110.
  19. 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.
  20. Wells LJ. Development of the human diaphragm and pleural sacs. (1954) Contrib. Embryol., Carnegie Inst. Wash. Publ. 603, 35: 107-134.
  21. Jirásek JE. Development of the Genital System and Male Pseudohermaphroditism. (1971) Johns Hopkins Press, Baltimore.
  22. Wilson KM. Origin and development of the rete ovarii and the rete testis in the human embryo. (1926) Carnegie Instn. Wash. Publ. 362, Contrib. Embryol., Carnegie Inst. Wash., 17:69-88.
  23. Gasser RL. Atlas of Human Embryos. (1975) Harper & Row, Hagerstown, Maryland.
  24. 24.0 24.1 Müller F & O'Rahilly R. (1990). The human brain at stages 18-20, including the choroid plexuses and the amygdaloid and septal nuclei. Anat. Embryol. , 182, 285-306. PMID: 2268071
  25. 25.0 25.1 Müller F & O'Rahilly R. (1990). The human brain at stages 21-23, with particular reference to the cerebral cortical plate and to the development of the cerebellum. Anat. Embryol. , 182, 375-400. PMID: 2252222
  26. Witt M & Reutter K. (1996). Embryonic and early fetal development of human taste buds: a transmission electron microscopical study. Anat. Rec. , 246, 507-23. PMID: 8955790 <507::AID-AR10>3.0.CO;2-S DOI.
  27. Müller F & O'Rahilly R. (1990). The human rhombencephalon at the end of the embryonic period proper. Am. J. Anat. , 189, 127-45. PMID: 2244584 DOI.
  28. O'Rahilly R, Muller F & Meyer DB. (1980). The human vertebral column at the end of the embryonic period proper. 1. The column as a whole. J. Anat. , 131, 565-75. PMID: 7216919
  29. Streeter GL. Developmental horizons in human embryos (fourth issue). A review of the histogenesis of cartilage and bone. (1949) Carnegie Instn. Wash. Publ. 583, Contrib. Embryol., 33: 149-169. PMID: 18144445
  30. Wünsch L & Schober JM. (2007). Imaging and examination strategies of normal male and female sex development and anatomy. Best Pract. Res. Clin. Endocrinol. Metab. , 21, 367-79. PMID: 17875485 DOI.
  31. Locher H, de Groot JC, van Iperen L, Huisman MA, Frijns JH & Chuva de Sousa Lopes SM. (2015). Development of the stria vascularis and potassium regulation in the human fetal cochlea: Insights into hereditary sensorineural hearing loss. Dev Neurobiol , 75, 1219-40. PMID: 25663387 DOI.
  32. Afif A, Bouvier R, Buenerd A, Trouillas J & Mertens P. (2007). Development of the human fetal insular cortex: study of the gyration from 13 to 28 gestational weeks. Brain Struct Funct , 212, 335-46. PMID: 17962979 DOI.