Timeline human development: Difference between revisions
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[[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 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 Crest Development|Neural Crest]] mesencephalic neural crest is visible | [[Neural Crest Development|Neural Crest]] mesencephalic neural crest is visible{{#pmid:17848161|PMID17848161}} | ||
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| <center>21</center> | | <center>21</center> | ||
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[[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 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 Crest Development|Neural Crest]] trigeminal, facial, and postotic ganglia components visible | [[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) | ||
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[[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 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_-_Ventricular_System_Development|Ventricular System]] Optic ventricle appears and the neural groove/tube space is initially filled with amniotic fluid. | [[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="F5FAFF" | |-bgcolor="F5FAFF" | ||
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[[Endocrine_-_Pituitary_Development|Pituitary]] Week 4 hypophysial pouch, Rathke's pouch, diverticulum from roof | [[Endocrine_-_Pituitary_Development|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 | [[Gastrointestinal_Tract_-_Liver_Development|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 System Development|Neural]] caudal neuropore takes a day to close (closure is approximately at future somitic pair 31/sacral vertebra 2) | ||
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[[Neural System Development|Neural]] secondary neurulation begins | [[Neural System Development|Neural]] secondary neurulation begins | ||
[[Neural_-_Ventricular_System_Development|Ventricular System]] onset of the ventricular system and separates the ependymal from the amniotic fluid. | [[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 | [[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{{#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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| <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. | | [[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.{{#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. | [[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 | [[Gastrointestinal_Tract_-_Liver_Development|Liver]] epithelial cord proliferation enmeshing stromal capillaries{{#pmid:9407542|PMID9407542}} | ||
[[Sensory_-_Smell_Development|Smell]] Crest comes from the nasal plates | [[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. | [[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.{{#pmid:7364662|PMID7364662}} | ||
[[Respiratory_System_-_Diaphragm|Diaphragm]] - pleuroperitoneal fold (PPF) first discernible in human embryos (CRL 6mm). | [[Respiratory_System_-_Diaphragm|Diaphragm]] - pleuroperitoneal fold (PPF) first discernible in human embryos (CRL 6mm).{{#pmid:19711422|PMID19711422}} | ||
|} | |} | ||
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| <center>29</center> | | <center>29</center> | ||
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| | | {{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_System_Development|Respiratory]] Week 5 to 17 lung histology - pseudoglandular | [[Respiratory_System_Development|Respiratory]] Week 5 to 17 lung histology - pseudoglandular | ||
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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. | [[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 | [[Neural System Development|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. | [[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 | [[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. | [[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 | [[Neural System Development|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, | [[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. | [[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="F5FAFF" | |-bgcolor="F5FAFF" | ||
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| <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 | | [[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. | [[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. | [[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 | ||
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[[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. | [[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 System Development|Neural]] | * [[Neural System Development|Neural]] | ||
** telencephalon areas of the future archicortex, paleocortex, and neocortex, visible. Beginning of future choroid plexus | ** 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 | ** 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 | * [[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) | * [[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) | * [[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" /> | ||
|- | |- | ||
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[[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 | [[Neural System Development|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 | [[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. | [[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 | [[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. | [[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}} | ||
|- | |- | ||
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[[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 | produces ductal plates that receive biliary capillaries{{#pmid:9407542|PMID9407542}} | ||
|-bgcolor="F5FAFF" | |-bgcolor="F5FAFF" | ||
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| [[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. | * [[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}} | ||
** | ** {{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> | ||
** [[Uterus Development|Uterus]] Müllerian duct grows independently from the invagination of the coelomic epithelium during stages 19-23 | ** [[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. | ** [[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 System Development|Neural]] | ||
** rhombencephalon migration for olivary and arcuate nuclei begins. | ** rhombencephalon migration for olivary and arcuate nuclei begins. | ||
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** 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 | ** 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. | ** [[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> | ||
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[[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 | [[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 | ||
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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. | [[Integumentary_System_-_Eyelid_Development|Eyelid]] the inner canthus is established.{{#pmid:7364662|PMID7364662}} | ||
|-bgcolor="F5FAFF" | |-bgcolor="F5FAFF" | ||
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| [[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 | [[Neural System Development|Neural]] cortical plate appears in the area of future insula{{#pmid:2252222|PMID2252222}} | ||
[[Neural - Vascular Development]] - formation of the anterior communicating artery. | [[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 | ||
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[[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. | [[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="F5FAFF" | |-bgcolor="F5FAFF" | ||
| <center>53</center> | | <center>53</center> | ||
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| <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 | | [[File:Stage22_bf1c.jpg|90px|link=Carnegie_stage_22]] [[Neural System Development|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 | [[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 | [[Uterus Development|Uterus]] [[Vagina Development|Vagina]] fused duct (uterovaginal canal) bifurcated at the caudal portion at Carnegie stages 22 and 23{{#pmid:12740945|PMID12740945}} | ||
|- | |- | ||
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[[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) | [[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 701: | Line 701: | ||
[[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 | [[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{{#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) | [[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. | [[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> </center> | | <center> </center> | ||
Line 711: | Line 711: | ||
| [[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. | [[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}} | ||
|} | |} | ||
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| [[File:Size comparison embryo-fetus actual.jpg|90px|link=Fetal Development]] | | [[File:Size comparison embryo-fetus actual.jpg|90px|link=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" | |-bgcolor="F5FAFF" | ||
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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 - | 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 | ||
Line 798: | Line 798: | ||
[[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. | [[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. | ||
[[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. | [[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.{{#pmid:25663387|PMID25663387}} | ||
|-bgcolor="F5FAFF" | |-bgcolor="F5FAFF" | ||
| <center>65</center> | | <center>65</center> | ||
Line 841: | Line 841: | ||
| '''Event''' | | '''Event''' | ||
[[Neural_System_Development|Neural]] - [[Neural - Cerebrum Development|Cerebrum]] appearance of the first sulcus (week 11-15, {{GA}} 13-17 weeks) | [[Neural_System_Development|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> | ||
Line 928: | Line 928: | ||
[[Head Development]] facial skeleton remodelling begins | [[Head Development]] facial skeleton remodelling begins | ||
[[Hearing - Inner Ear Development|Hearing - Inner Ear Development]] Week 14 {{GA}} 16 - neural-crest-derived melanocytes, now intermediate cells of the stria vascularis, tightly integrate with Na+ /K+ -ATPase-positive marginal cells, which started to express KCNQ1 in their apical membrane. | [[Hearing - Inner Ear Development|Hearing - Inner Ear Development]] Week 14 {{GA}} 16 - neural-crest-derived melanocytes, now intermediate cells of the stria vascularis, tightly integrate with Na+ /K+ -ATPase-positive marginal cells, which started to express KCNQ1 in their apical membrane.{{#pmid:25663387|PMID25663387}} | ||
|- | |- | ||
Line 935: | Line 935: | ||
| [[Endocrine_-_Pancreas_Development|Pancreas]] glucagon detectable in fetal plasma. | | [[Endocrine_-_Pancreas_Development|Pancreas]] glucagon detectable in fetal plasma. | ||
{{spleen}} Week 15 -alpha-smooth muscle actin (alpha-SMA)-positive reticulum cells scattered around the arterioles.{{#pmid:19255788|PMID19255788}} | |||
===Fetal Timeline=== | ===Fetal Timeline=== | ||
Line 950: | Line 950: | ||
[[Hearing_-_Outer_Ear_Development|Hearing - Outer Ear Development]] Week 16.5 - External auditory meatus is fully patent throughout its length, lumen is still narrow and curved. | [[Hearing_-_Outer_Ear_Development|Hearing - Outer Ear Development]] Week 16.5 - External auditory meatus is fully patent throughout its length, lumen is still narrow and curved. | ||
[[Hearing - Inner Ear Development|Hearing - Inner Ear Development]] Week 16 {{GA}} 18 - cells in the outer sulcus express KCNJ10 and gap junction proteins GJB2/CX26 and GJB6/CX30, but these are not expressed in the spiral ligament. | [[Hearing - Inner Ear Development|Hearing - Inner Ear Development]] Week 16 {{GA}} 18 - cells in the outer sulcus express KCNJ10 and gap junction proteins GJB2/CX26 and GJB6/CX30, but these are not expressed in the spiral ligament.{{#pmid:25663387|PMID25663387}} [[:File:Gap junction 01.jpg|gap junction cartoon]] | ||
[[Neural_System_Development|Neural]] - [[Neural - Cerebrum Development|Cerebrum]] development of the periinsular sulci (week 16-17, {{GA}} 18-19 weeks) | [[Neural_System_Development|Neural]] - [[Neural - Cerebrum Development|Cerebrum]] development of the periinsular sulci (week 16-17, {{GA}} 18-19 weeks){{#pmid:17962979|PMID17962979}} | ||
Line 972: | Line 972: | ||
| <center>18</center> | | <center>18</center> | ||
| | | | ||
| [[File:Bailey095.jpg|90px]] | | [[File:Bailey095.jpg|90px]]{{tongue}} Week 18 - substance P detected in dermal papillae, not in taste bud primordia | ||
{{integumentary}} vernix caseosa covers skin | |||
[[Cardiovascular_System_-_Spleen_Development|Spleen]] Week 18 - alpha-SMA-positive reticulum cells increase in number and began to form a reticular framework. An accumulation of T and B lymphocytes occurred within the framework, and a primitive white pulp was observed around the arterioles. | [[Cardiovascular_System_-_Spleen_Development|Spleen]] Week 18 - alpha-SMA-positive reticulum cells increase in number and began to form a reticular framework. An accumulation of T and B lymphocytes occurred within the framework, and a primitive white pulp was observed around the arterioles.{{#pmid:19255788|PMID19255788}} | ||
[[Hearing_-_Outer_Ear_Development|Hearing - Outer Ear Development]] week 18 - External auditory meatus is already fully expanded to its complete form. | [[Hearing_-_Outer_Ear_Development|Hearing - Outer Ear Development]] week 18 - External auditory meatus is already fully expanded to its complete form. | ||
[[Neural_System_Development|Neural]] - [[Neural - Cerebrum Development|Cerebrum]] central sulci and opercularization of the insula (week 18-20, {{GA}} 20-22 weeks) | [[Neural_System_Development|Neural]] - [[Neural - Cerebrum Development|Cerebrum]] central sulci and opercularization of the insula (week 18-20, {{GA}} 20-22 weeks){{#pmid:17962979|PMID17962979}} | ||
|- | |- | ||
| <center>19</center> | | <center>19</center> | ||
| | | | ||
| [[Neural System Development|Neural]] week 19 neuronal migration ends and the [[Neural_System_-_Glial_Development#Radial_Glia|radial glial cells]] that aided the migration now become transformed into astrocytes and astrocytic precursors. | | [[Neural System Development|Neural]] week 19 neuronal migration ends and the [[Neural_System_-_Glial_Development#Radial_Glia|radial glial cells]] that aided the migration now become transformed into astrocytes and astrocytic precursors.{{#pmid:3339373|PMID3339373}} | ||
|-bgcolor="F5FAFF" | |-bgcolor="F5FAFF" | ||
| <center>20</center> | | <center>20</center> | ||
| | | | ||
| | | {{pituitary}} week 20 to 24 growth hormone levels peak, then decline | ||
{{integumentary}} lanugo, skin hair | |||
[[Integumentary_System_Development|Skin]] 5 months - Hair growth initiated at base of cord, lateral outgrowths form associated sebaceous glands; Other cords elongate and coil to form sweat glands; Cords in mammary region branch as they elongate to form mammary glands. | [[Integumentary_System_Development|Skin]] 5 months - Hair growth initiated at base of cord, lateral outgrowths form associated sebaceous glands; Other cords elongate and coil to form sweat glands; Cords in mammary region branch as they elongate to form mammary glands. | ||
Line 1,004: | Line 1,004: | ||
| <center>22</center> | | <center>22</center> | ||
| | | | ||
| [[File:Gray0038.jpg|90px|link=Fetal Development]] [[Neural System Development|Neural]] brain cortical sulcation - sylvian fissure, interhemispheric fissure, callosal sulcus, parietooccipital fissure, and hippocampic fissures present | | [[File:Gray0038.jpg|90px|link=Fetal Development]] [[Neural System Development|Neural]] brain cortical sulcation - sylvian fissure, interhemispheric fissure, callosal sulcus, parietooccipital fissure, and hippocampic fissures present{{#pmid:11158907|PMID11158907}} | ||
[[Cardiovascular_System_-_Spleen_Development|Spleen]] - Week 22 - antigenic diversity of the reticular framework was observed, and T and B lymphocytes were segregated in the framework. T lymphocytes were sorted into the alpha-smooth muscle actin-positive reticular framework, and the periarteriolar lymphoid sheath (PALS) was formed around the arteriole. B lymphocytes aggregated in eccentric portions to the PALS and formed the lymph follicle (LF). The reticular framework of the LF was alpha-SMA-negative. | [[Cardiovascular_System_-_Spleen_Development|Spleen]] - Week 22 - antigenic diversity of the reticular framework was observed, and T and B lymphocytes were segregated in the framework. T lymphocytes were sorted into the alpha-smooth muscle actin-positive reticular framework, and the periarteriolar lymphoid sheath (PALS) was formed around the arteriole. B lymphocytes aggregated in eccentric portions to the PALS and formed the lymph follicle (LF). The reticular framework of the LF was alpha-SMA-negative. {{#pmid:19255788|PMID19255788}} | ||
[[Neural_System_Development|Neural]] - [[Neural - Cerebrum Development|Cerebrum]] covering of the posterior insula (week 22-24, {{GA}} 24-26 weeks) | [[Neural_System_Development|Neural]] - [[Neural - Cerebrum Development|Cerebrum]] covering of the posterior insula (week 22-24, {{GA}} 24-26 weeks){{#pmid:17962979|PMID17962979}} | ||
|- | |- | ||
Line 1,018: | Line 1,018: | ||
| | | | ||
| [[Respiratory_System_Development|Respiratory]] Week 24 to 40 lung histology - terminal sac | | [[Respiratory_System_Development|Respiratory]] Week 24 to 40 lung histology - terminal sac | ||
[[Cardiovascular_System_-_Spleen_Development|Spleen]] Week 24 - marginal zone appeared in the alpha-smooth muscle actin-positive reticular framework around the white pulp. | [[Cardiovascular_System_-_Spleen_Development|Spleen]] Week 24 - marginal zone appeared in the alpha-smooth muscle actin-positive reticular framework around the white pulp.{{#pmid:19255788|PMID19255788}} | ||
{{tooth}} Week 24 - Permanent incisors and canines appear. | |||
Earliest potential survival expected if born | Earliest potential survival expected if born | ||
Line 1,029: | Line 1,030: | ||
| [[Respiratory_System_Development|Respiratory]] end month 6 alveolar cells type 2 appear and begin to secrete surfactant | | [[Respiratory_System_Development|Respiratory]] end month 6 alveolar cells type 2 appear and begin to secrete surfactant | ||
[[Neural_System_Development|Neural]] - [[Neural - Cerebrum Development|Cerebrum]] closure of the laeteral sulcus (Sylvian fissure or lateral fissure) (week 25-26, {{GA}} 27-28 weeks) | [[Neural_System_Development|Neural]] - [[Neural - Cerebrum Development|Cerebrum]] closure of the laeteral sulcus (Sylvian fissure or lateral fissure) (week 25-26, {{GA}} 27-28 weeks){{#pmid:17962979|PMID17962979}} | ||
|} | |} | ||
Line 1,045: | Line 1,046: | ||
| | | | ||
| Clinical third trimester | | Clinical third trimester | ||
| [[File:Fetal_size_change.jpg|90px|link=Fetal Development]] | | [[File:Fetal_size_change.jpg|90px|link=Fetal Development]] {{hearing}} 3rd Trimester - vibration acoustically of maternal abdominal wall induces startle respone in fetus. | ||
|-bgcolor="F5FAFF" | |-bgcolor="F5FAFF" | ||
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| <center>28</center> | | <center>28</center> | ||
| | | | ||
| | | {{respiratory}} Month 7 - respiratory bronchioles proliferate and end in alveolar ducts and sacs | ||
|-bgcolor="F5FAFF" | |-bgcolor="F5FAFF" | ||
Line 1,061: | Line 1,062: | ||
| | | | ||
| | | | ||
{{tooth}} Week 29 - Permanent premolars (correspond to the milk molars) appear. | |||
|- | |- | ||
| <center>30</center> | | <center>30</center> | ||
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| <center>32</center> | | <center>32</center> | ||
| | | | ||
| | | {{nail}} fingernails reach digit tip | ||
|-bgcolor="F5FAFF" | |-bgcolor="F5FAFF" | ||
| <center>33</center> | | <center>33</center> | ||
| | | | ||
| [[Neural System Development|Neural]] brain cortical sulcation - primary sulci present | | [[Neural System Development|Neural]] brain cortical sulcation - primary sulci present{{#pmid:11158907|PMID11158907}} | ||
|- | |- | ||
| <center>34</center> | | <center>34</center> | ||
| | | | ||
| [[Neural System Development|Neural]] brain cortical sulcation - insular, cingular, and occipital secondary sulci present | | [[Neural System Development|Neural]] brain cortical sulcation - insular, cingular, and occipital secondary sulci present{{#pmid:11158907|PMID11158907}} | ||
|-bgcolor="F5FAFF" | |-bgcolor="F5FAFF" | ||
Line 1,099: | Line 1,100: | ||
| [[File:Frazer006_bw600.jpg|90px|link=Fetal Development]] [[Integumentary_System_-_Nail_Development|Nail Development]] toenails reach digit tip | | [[File:Frazer006_bw600.jpg|90px|link=Fetal Development]] [[Integumentary_System_-_Nail_Development|Nail Development]] toenails reach digit tip | ||
[[Vision_-_Lens_Development|Lens Development]] - lens growth and interocular distance plateaus after 36 weeks of gestation | [[Vision_-_Lens_Development|Lens Development]] - lens growth and interocular distance plateaus after 36 weeks of gestation{{#pmid:19541779|PMID19541779}} | ||
|-bgcolor="F5FAFF" | |-bgcolor="F5FAFF" | ||
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[[Cardiovascular System Development|Heart]] pressure difference closes foramen ovale leaving a fossa ovalis | [[Cardiovascular System Development|Heart]] pressure difference closes foramen ovale leaving a fossa ovalis | ||
{{thyroid}} TSH levels increase, thyroxine (T3) and T4 levels increase to 24 h, then 5-7 days postnatal decline to normal levels | |||
{{adrenal}} - zona glomerulosa, zona fasiculata present | |||
Line 1,148: | Line 1,149: | ||
| <center>+4</center> | | <center>+4</center> | ||
| | | | ||
| | | {{vision}} - eye globe growth plateaus after 42 weeks of gestation{{#pmid:19541779|PMID19541779}} | ||
| | | | ||
Line 1,158: | Line 1,159: | ||
| <center>'''Month'''</center> | | <center>'''Month'''</center> | ||
| | | | ||
| | | {{testis}} | {{spermatozoa}} - about 2 months of age, primordial germ cells (gonocytes) are replaced by adult dark (Ad) and pale (Ap) spermatogonia forming the spermatogonial stem cell (SSC) population that at puberty will commence differentiation into spermatozoa. | ||
|-bgcolor="F5FAFF" | |-bgcolor="F5FAFF" | ||
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| <center>Year 1</center> | | <center>Year 1</center> | ||
| | | | ||
| | | {{neural}} [[Sensory_-_Hearing_and_Balance_Development|Hearing]] (6 months to 5 years) thalamocortical afferents to the deeper cortical layers mature and are the first source of input to the auditory cortex{{#pmid:12018354|PMID12018354}} | ||
{{Normal 12 Month Neural Exam Table}} | {{Normal 12 Month Neural Exam Table}} | ||
Line 1,191: | Line 1,192: | ||
| <center>5</center> | | <center>5</center> | ||
| | | | ||
| [[Neural System Development|Neural]] [[Sensory_-_Hearing_and_Balance_Development|Hearing]] - (5 to 12 years) commissural and association axons in the superficial cortical layers allows communication between subdivisions of the auditory cortex | | [[Neural System Development|Neural]] [[Sensory_-_Hearing_and_Balance_Development|Hearing]] - (5 to 12 years) commissural and association axons in the superficial cortical layers allows communication between subdivisions of the auditory cortex{{#pmid:12018354|PMID12018354}} | ||
|-bgcolor="F5FAFF" | |-bgcolor="F5FAFF" |
Revision as of 00:22, 11 May 2018
Embryology - 27 Apr 2024 Expand to Translate |
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Introduction
From a cell | to a newborn infant |
in 9 months. |
This page is organised to show week by week human development features and approximate timing of key events with more detailed information about specific events in different systems. For a less detailed timeline see week by week.
Note:
- The "weeks" refer to embryonic development and differ from clinical weeks (shown in brackets, from the first day of the Last Menstrual Period, LMP or GA)
- The "stages" refer to Carnegie stages of development.
- The "timing" refers to days from fertilization or post conception age (PC), not the clinical or gestational age (GA) calculated from LMP (add 2 weeks).
- The dates and staging are also "ideal", and there is significant biological variability in the general timing of events.
- Week 1 to Week 8 are considered the embryonic period of development.
- Week 9 to week 37 or birth are considered the fetal period of development.
- The first month after birth is the neonatal period of development.
Each developmental feature is linked to online content with more detailed information and resources such as images and movies. The superscript numbers are the original source references.
There are similar "timelines" for other species shown below.
Week -2
(GA Clinical Week 1)
Event | ||
Menstrual Phase |
Menstrual Cycle changes: Uterine endometrium (loss), Ovary (Follicle Development) | |
Proliferative Phase | Menstrual Cycle changes: Uterine endometrium (proliferation), Ovary (Follicle Development) | |
Week -1
(Clinical Week 2)
Menstrual cycle | Event | |
Proliferative Phase | ||
Menstrual Cycle - Mid proliferative | ||
Menstrual Cycle - Late Proliferative | ||
Ovulation
Capacitation |
Week 1
Event | ||
Secretory Phase | Fertilization, Secretory Phase | |
Stage 2 | Morula, Blastula | |
Blastocyst Development | ||
Stage 3 | Blastocyst Hatching (zona pellucida lost) | |
Late Secretory, Blastocyst (free floating) | ||
Stage 4 | Adplantation | |
Stage 5 |
Week 2
Event | ||
Implantation | ||
Stage 6 | Chorionic Cavity | |
Week 3
Event | ||
Stage 7 | ||
Stage 8 | Neural neurogenesis, neural groove and folds are first seen | |
Stage 9 | 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] | |
Heart cardiogenesis, week 3 begins as paired heart tubes. |
Week 4
Event | ||
Stage 10 |
Neural Crest differentiation at spinal cord level from day 22 until day 26 Neural 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. | |
Heart begins to beat in Humans by day 22-23, first functioning embryonic organ formed. | ||
Stage 11 |
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] | |
Stage 12 |
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 arteriosusPubmedParser error: Invalid PMID, please check. (PMID: 17848161}PMID17848161) Neural Crest vagal neural crest enter the foregut (20-25 somite stage) | |
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.[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
Event | ||
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) | ||
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 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] | |
Stage 15 |
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] | |
Vision 35 to 37 days retinal pigment present |
Week 6
Event | ||
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) | ||
Stage 16 | 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] | |
Stage 17 |
| |
Heart separation of common cardiac outflow (aortic arch and pulmonary aorta) |
Week 7
Event | ||
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 | ||
Stage 18 |
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] | |
Liver (stage 18 to 23) biliary ductules developed in periportal connective tissue produces ductal plates that receive biliary capillaries[3] | ||
Stage 19 |
| |
Week 8
Event | ||
Stage 20 |
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 | |
Gastrointestinal Tract anal membrane perforates | ||
Stage 21 |
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] | |
Stage 22 | 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] | |
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] | ||
Stage 23 | 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)
Event | ||
Fetal Period |
hearing Week 9 - mesenchyme surrounding membranous labrynth (otic capsule) chondrifies smell Embryonic/Fetal transition - localized incomplete lamination of the olfactory bulb[6] | |
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)
Event | ||
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 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. 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.[29] | ||
Week 10 - CRL 55 mm, femur length 9 mm, biparietal diameter 17 mm |
Week 11
(GA Clinical Week 13)
Event
Neural - Cerebrum appearance of the first sulcus (week 11-15, GA 13-17 weeks)[30] | ||
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. | ||
Week 11 - CRL 68 mm, femur length 12 mm, biparietal diameter 20 mm |
Second Trimester
(GA Clinical Week 14) Second Trimester
Event | ||
Clinical second trimester | Week 12 - CRL 85 mm, femur length 15 mm, biparietal diameter 25 mm
Hearing Week 12-16 - Capsule adjacent to membranous labrynth undegoes vacuolization to form a cavity (perilymphatic space) around membranous labrynth and fills with perilymph
Respiratory Month 3-6 - lungs appear glandular, end month 6 alveolar cells type 2 appear and begin to secrete surfactant Tongue Week 12 - first differentiated epithelial cells (Type II and III) Genital female genital canal (80 days) formed with absorption of the median septum | |
Tongue Week 12 to 13 - maximum synapses between cells and afferent nerve fibers
Hearing - Outer Ear Development Week 13 - Meatal plug disc-like, innermost surface in contact with the primordial malleus, contributes to the formation of the tympanic membrane. | ||
Tongue Week 14 to 15 - taste pores develop, mucous
Ovary Development 100 days - primary follicles present Nail Development toenails appear Head Development facial skeleton remodelling begins Hearing - Inner Ear Development Week 14 GA 16 - neural-crest-derived melanocytes, now intermediate cells of the stria vascularis, tightly integrate with Na+ /K+ -ATPase-positive marginal cells, which started to express KCNQ1 in their apical membrane.[29] | ||
Pancreas glucagon detectable in fetal plasma.
spleen Week 15 -alpha-smooth muscle actin (alpha-SMA)-positive reticulum cells scattered around the arterioles.[31] Fetal Timeline | ||
14 cm | Hearing Week 16-24 - Centres of ossification appear in remaining cartilage of otic capsule form petrous portion of temporal bone. Continues to ossify to form mastoid process of temporal bone.
Pituitary adenohypophysis fully differentiated Respiratory Week 16 to 25 lung histology - canalicular Hearing - Outer Ear Development Week 16.5 - External auditory meatus is fully patent throughout its length, lumen is still narrow and curved. Hearing - Inner Ear Development Week 16 GA 18 - cells in the outer sulcus express KCNJ10 and gap junction proteins GJB2/CX26 and GJB6/CX30, but these are not expressed in the spiral ligament.[29] gap junction cartoon Neural - Cerebrum development of the periinsular sulci (week 16-17, GA 18-19 weeks)[30]
primary follicles begin to form in the ovary and are characterized by an oocyte glandular urethra forms and skin folds present | |
Neural - Brain development histology week 17
Cerebellum Magnetic Resonance Imaging (MRI) can study the developing cerebellum from 17 to 18 weeks (GA 19 to 20 weeks). Tooth Development Week 17 - First papilla of the permanent dentition appear (first molar) immediately behind the second milk molar, milk teeth are well advanced (Fetus 180 mm). | ||
tongue Week 18 - substance P detected in dermal papillae, not in taste bud primordia
integumentary vernix caseosa covers skin Spleen Week 18 - alpha-SMA-positive reticulum cells increase in number and began to form a reticular framework. An accumulation of T and B lymphocytes occurred within the framework, and a primitive white pulp was observed around the arterioles.[31] Hearing - Outer Ear Development week 18 - External auditory meatus is already fully expanded to its complete form. Neural - Cerebrum central sulci and opercularization of the insula (week 18-20, GA 20-22 weeks)[30] | ||
Neural week 19 neuronal migration ends and the radial glial cells that aided the migration now become transformed into astrocytes and astrocytic precursors.[32] | ||
pituitary week 20 to 24 growth hormone levels peak, then decline
integumentary lanugo, skin hair Skin 5 months - Hair growth initiated at base of cord, lateral outgrowths form associated sebaceous glands; Other cords elongate and coil to form sweat glands; Cords in mammary region branch as they elongate to form mammary glands. | ||
Neural brain cortical sulcation - sylvian fissure, interhemispheric fissure, callosal sulcus, parietooccipital fissure, and hippocampic fissures present[33]
Spleen - Week 22 - antigenic diversity of the reticular framework was observed, and T and B lymphocytes were segregated in the framework. T lymphocytes were sorted into the alpha-smooth muscle actin-positive reticular framework, and the periarteriolar lymphoid sheath (PALS) was formed around the arteriole. B lymphocytes aggregated in eccentric portions to the PALS and formed the lymph follicle (LF). The reticular framework of the LF was alpha-SMA-negative. [31] Neural - Cerebrum covering of the posterior insula (week 22-24, GA 24-26 weeks)[30] | ||
Respiratory Week 24 to 40 lung histology - terminal sac
Spleen Week 24 - marginal zone appeared in the alpha-smooth muscle actin-positive reticular framework around the white pulp.[31] tooth Week 24 - Permanent incisors and canines appear. Earliest potential survival expected if born ovarian follicles can consist of growing oocytes surrounded by several layers of granulosa cells | ||
Respiratory end month 6 alveolar cells type 2 appear and begin to secrete surfactant
Neural - Cerebrum closure of the laeteral sulcus (Sylvian fissure or lateral fissure) (week 25-26, GA 27-28 weeks)[30] |
Third Trimester
(GA Clinical Week 28) Third Trimester
Event | ||
Clinical third trimester | hearing 3rd Trimester - vibration acoustically of maternal abdominal wall induces startle respone in fetus. | |
respiratory Month 7 - respiratory bronchioles proliferate and end in alveolar ducts and sacs | ||
tooth Week 29 - Permanent premolars (correspond to the milk molars) appear. | ||
Genital male gonad (testes) descending | ||
nail fingernails reach digit tip | ||
Neural brain cortical sulcation - primary sulci present[33] | ||
Neural brain cortical sulcation - insular, cingular, and occipital secondary sulci present[33] | ||
Nail Development toenails reach digit tip
Lens Development - lens growth and interocular distance plateaus after 36 weeks of gestation[34] | ||
Birth | Clinical Week 40
Heart pressure difference closes foramen ovale leaving a fossa ovalis thyroid TSH levels increase, thyroxine (T3) and T4 levels increase to 24 h, then 5-7 days postnatal decline to normal levels adrenal - zona glomerulosa, zona fasiculata present
|
Postnatal
Event | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
vision - eye globe growth plateaus after 42 weeks of gestation[34] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
testis | spermatozoa - about 2 months of age, primordial germ cells (gonocytes) are replaced by adult dark (Ad) and pale (Ap) spermatogonia forming the spermatogonial stem cell (SSC) population that at puberty will commence differentiation into spermatozoa. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
neural Hearing (6 months to 5 years) thalamocortical afferents to the deeper cortical layers mature and are the first source of input to the auditory cortex[35]
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Adrenal - Year 3 zona reticularis present.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Neural Hearing - (5 to 12 years) commissural and association axons in the superficial cortical layers allows communication between subdivisions of the auditory cortex[35] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Puberty - Female | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Puberty - Male |
References
- ↑ 1.0 1.1 O'Rahilly R & Müller F. (2007). The development of the neural crest in the human. J. Anat. , 211, 335-51. PMID: 17848161 DOI.
- ↑ 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.
- ↑ 3.0 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.
- ↑ 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
- ↑ 5.0 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.
- ↑ 6.0 6.1 6.2 6.3 6.4 Müller F & O'Rahilly R. (2004). Olfactory structures in staged human embryos. Cells Tissues Organs (Print) , 178, 93-116. PMID: 15604533 DOI.
- ↑ 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
- ↑ 8.0 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.
- ↑ 9.0 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.
- ↑ 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
- ↑ Patelska-Banaszewska M & Woźniak W. (2005). The subarachnoid space develops early in the human embryonic period. Folia Morphol. (Warsz) , 64, 212-6. PMID: 16228957
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 15.0 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
- ↑ 16.0 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.
- ↑ Keibel F. and Mall FP. Manual of Human Embryology II. (1912) J. B. Lippincott Company, Philadelphia.
- ↑ 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.
- ↑ Wells LJ. Development of the human diaphragm and pleural sacs. (1954) Contrib. Embryol., Carnegie Inst. Wash. Publ. 603, 35: 107-134.
- ↑ Jirásek JE. Development of the Genital System and Male Pseudohermaphroditism. (1971) Johns Hopkins Press, Baltimore.
- ↑ 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.
- ↑ Gasser RL. Atlas of Human Embryos. (1975) Harper & Row, Hagerstown, Maryland.
- ↑ 23.0 23.1 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
- ↑ 24.0 24.1 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
- ↑ 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.
- ↑ 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.
- ↑ 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
- ↑ 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.
- ↑ 29.0 29.1 29.2 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.
- ↑ 30.0 30.1 30.2 30.3 30.4 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.
- ↑ 31.0 31.1 31.2 31.3 Satoh T, Sakurai E, Tada H & Masuda T. (2009). Ontogeny of reticular framework of white pulp and marginal zone in human spleen: immunohistochemical studies of fetal spleens from the 17th to 40th week of gestation. Cell Tissue Res. , 336, 287-97. PMID: 19255788 DOI.
- ↑ Kadhim HJ, Gadisseux JF & Evrard P. (1988). Topographical and cytological evolution of the glial phase during prenatal development of the human brain: histochemical and electron microscopic study. J. Neuropathol. Exp. Neurol. , 47, 166-88. PMID: 3339373
- ↑ 33.0 33.1 33.2 Garel C, Chantrel E, Brisse H, Elmaleh M, Luton D, Oury JF, Sebag G & Hassan M. (2001). Fetal cerebral cortex: normal gestational landmarks identified using prenatal MR imaging. AJNR Am J Neuroradiol , 22, 184-9. PMID: 11158907
- ↑ 34.0 34.1 Paquette LB, Jackson HA, Tavaré CJ, Miller DA & Panigrahy A. (2009). In utero eye development documented by fetal MR imaging. AJNR Am J Neuroradiol , 30, 1787-91. PMID: 19541779 DOI.
- ↑ 35.0 35.1 Moore JK. (2002). Maturation of human auditory cortex: implications for speech perception. Ann Otol Rhinol Laryngol Suppl , 189, 7-10. PMID: 12018354
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Cite this page: Hill, M.A. (2024, April 27) Embryology Timeline human development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Timeline_human_development
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