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1 CE
Day 1
fertilized zygote
secretory phase stage one -
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Day 2
Morlua blastula
stage two -
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Day 3
blatocyst -
4
Day 4
blastocyst hatching
stage three -
5
Day 5
Late Secretory, blastocyst -
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Day 6
Adplantation
stage 4 -
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Day 7
stage 5 -
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Day 8
implantation -
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Day 9
Levels of hCG are now high enough in maternal blood to detect a pregnancy using a blood test. -
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day 10
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Day 11
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12
12
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13
stage 6 Chorionic Cavity -
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14
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15
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16
gastrulation, ectoderm, mesoderm, endoderm -
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17
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18
neural neurogenesis, neural groove and folds are first seen -
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19
stage 8 -
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20
stage 9 Musculoskeletal somitogenesis, -
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21
heart cardiogenesis, week 3 begins as paired heart tubes. -
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22
stage 10
neural Crest differentiation at spinal cord level from day 22 until day 26 neural folds begin to fuse near the junction between the brain and spinal cord -
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23
heart begins to beat in Humans by day 22-23, first functioning embryonic organ formed. -
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24
stage 11 thyroid median endodermal thickening in the floor of pharynx -
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25
ventricular onset of the ventricular system and separates the ependymal from the amniotic fluid stage 12 -
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26
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27
the neural tube is normally completely closed, the ventricular system now separated from amniotic fluid. Neural crest at the spinal level is segregating, and spinal ganglia are in series with the somites. Spinal cord ventral roots beginning to develop.[4]
telencephalon cavity appears -
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28
stage 13 integumentary 4 weeks - simple ectoderm epithelium over mesenchyme. 1-3 months ectoderm- germinative (basal) cell repeated division of generates stratified epithelium; mesoderm- differentiates into connective tissue and blood vessels -
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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 Week 5 to 17 lung histology - pseudoglandular hearing Week 5 cochlear part of otic vesicle elongates (huma -
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32
stage 14 codes sensory placodes, lens pit, otocyst, nasal placode, primary/secondary vesicles, fourth ventricle of brain.
Body - heart, liver, umbilical cord, mesonephric ridge visible externally as bulges. limb upper and lower limb buds growing. -
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33
neural cranial nerves (except olfactory and optic) are identifiable in more advanced embryo -
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34
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35
vision 35 to 37 days retinal pigment present pituitary Week 6 - connecting stalk between pouch and oral cavity degenerates
parathyroid Week 6 - diverticulum elongate, hollow then solid, dorsal cell proliferation -
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36
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) -
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37
stage 16 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 -
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38
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39
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40
40
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41
41
stage 17 smell olfactory nerve fibres enter the brain
Eyelid sulcus (groove) above and below eye deepen and eyelid folds develop (below first and then above)
Diaphragm - pleuroperitoneal fold (PPF) no longer separated from the diaphragm (CRL 14mm)
Abdominal Wall muscle cells now migrated approximately 50% of the distance to the ventral midline, inner and outer layers were not discernible yet. -
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42
heart separation of common cardiac outflow (aortic arch and pulmonary aorta) -
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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 -
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44
stage 18 Stage18
limb bone forms by endochondrial ossification and throughout embryo replacement of cartilage with bone (week 5-12). neural smell vomeronasal fibres and nervus terminali -
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45
liver (stage 18 to 23) biliary ductules developed in periportal connective tissue produces ductal plates that receive biliary capillaries[ -
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46
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47
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 -
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48
stage 19 Respiratory - first generation of subsegmental bronchi now complete, see bronchial tree reconstruction(plates 3 and 4).
gastrointestinal tract - anal membrane defined.
renal - Cloacal membrane ruptures from urinary pressure at stage 18 or stage 19, genital -
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49
Head scalp vascular plexus visible limb upper limbs begin to rotate ventrally neural amygdaloid body has at least four individual nuclei -
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50
stage 20 choroid plexuses of the fourth and lateral ventricles Eyelid the inner canthus is established. -
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51
gastrointestinal tract anal membrane perforates -
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52
stage 21 neural cortical plate appears in the area of future insula Neural - Vascular Development - formation of the anterior communicating artery. limb upper and lower limbs rotate Intraembryonic Coelom pericardioperitoneal canals close -
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53
neural neocortical fibres project to epithalamus, to dorsal thalamus, and to mesencephalon[25]
limb fingers and toes lengthen -
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54
stage 22 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 -
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55
end of embryonic organogenesis period -
56
Day 56
stage 23
week 8
beginning of fetal development
