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This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. (help, get involved!) Any material not supported by sources may be challenged and removed at any time, although it may be a good idea to ask for specific sources first. This article has been tagged since January 2007. In embryology, Carnegie stages are a standardized system of 23 stages used to provide a unified developmental chronology of the vertebrate embryo. Image File history File links This is a lossless scalable vector image. ...
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Classes and Clades See below Male and female Superb Fairy-wren Vertebrates are members of the subphylum Vertebrata (within the phylum Chordata), specifically, those chordates with backbones or spinal columns. ...
It has been suggested that embryology be merged into this article or section. ...
The stages are delineated through the development of structures, not by size or the number of days of development, and so the chronology can vary between species, and to a certain extent between embryos. It only covers the first 60 days of development; at that point the term embryo is usually replaced with the term fetus. It has been suggested that embryology be merged into this article or section. ...
Human fetus at eight weeks. ...
It was based on work by Streeter (1942) and O'Rahilly and Müller (1987). The name "Carnegie stages" comes from the Carnegie Institute. The Carnegie Institution of Washington (CIW) is a foundation established by Andrew Carnegie in 1902 to support scientific research. ...
While the Carnegie stages provide a universal system for staging and comparing the embryonic development of most vertebrates, other systems are occasionally used for the common model organisms in developmental biology, such as the Hamburger-Hamilton stages in the chick. A model organism is a species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the organism model will provide insight into the workings of other organisms. ...
Views of a Foetus in the Womb, Leonardo da Vinci, ca. ...
In developmental biology, the Hamburger-Hamilton stages (HH) are a series of 46 chronological stages in chick development, starting from laying of the egg and ending with a newly hatched chick. ...
This article or section does not adequately cite its references or sources. ...
Stages
Days are approximate, and reflect the days since the last ovulation before pregnancy ("Postovulatory age"). Ovulation is the process in the menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum (also known as an oocyte, female gamete, or casually, an egg) that participates in reproduction. ...
A pregnant woman near the end of her term Pregnancy is the carrying of one or more embryos or fetuses by female mammals, including humans, inside their bodies. ...
Stage 1: 1 days Categories: Biology stubs ...
The Polar body is a cell structure found inside an ovum. ...
Stage 2: 3 days In embryology, cleavage is the division of cells in the early embryo. ...
Morula is a stage of embryonic development in animals, including the 16-cell phase, the 32-cell phase, and the 64-cell phase. ...
Stage 3: 4 days The blastocyst is the structure formed in early mammalian embryogenesis, after the formation of the blastocele, but before implantation. ...
A blastocoel(e) or blastocele or cleavage cavity or segmentation cavity is the central region of a blastocyst. ...
The floor of the amniotic cavity is formed by the embryonic disk (or embryonic disc) composed of a layer of prismatic cells, the embryonic ectoderm, derived from the inner cell-mass and lying in apposition with the entoderm. ...
The trophoblast (from Greek threphein: to feed) is considered to be the first of all embryonic annexes. ...
Stage 4: 5-6 days Syncytiotrophoblasts are cells found in the placenta of human embryos. ...
The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ...
The ectoderm is outermost of the three germ layers of the developing embryo, the other two being the mesoderm and the endoderm. ...
Stage 5 (a-c): 7-12 days Implantation occurs when a fertilized zygote attaches itself onto the lining of the uterus. ...
The yolk sac is the first element seen in the gestational sac during pregnancy, usually at 5 weeks gestation. ...
amniotic sac The amniotic sac is a tough but thin transparent pair of membranes, which hold a developing embryo (and later fetus) until shortly before birth. ...
Stage 6: 13-15 days The primitive streak is a structure that forms during the early stages of avian, reptilian and mammalian embryonic development. ...
A shallow groove, the primitive groove, appears on the surface of the primitive streak, and the anterior end of this groove communicates by means of an aperture, the blastophore, with the yolk-sac. ...
The chorion undergoes rapid proliferation and forms numerous processes, the chorionic villi, which invade and destroy the uterine decidua and at the same time absorb from it nutritive materials for the growth of the embryo. ...
The yolk sac is the first element seen in the gestational sac during pregnancy, usually at 5 weeks gestation. ...
Stage 7: 15-17 days 1 - blastula, 2 - gastrula; orange - ectoderm, red - endoderm. ...
The neural plate is thick and flat bundle of ectoderm which develops in the embryo into the nervous system. ...
Haematopoiesis is the formation of blood cellular components. ...
The notochord is a flexible, rod-shaped body found in embryos of all chordates. ...
Stage 8: 17-19 days Stage 9: 19-21 days Between the neural folds is a shallow median groove, the neural groove. ...
In front of the primitive streak two longitudinal ridges, caused by a folding up of the ectoderm, make their appearance, one on either side of the middle line. ...
The liver arises in the form of a diverticulum or hollow outgrowth from the ventral surface of that portion of the gut which afterward becomes the descending part of the duodenum. ...
A placode is an area of thickening in the embryonic epithelial layer where some organ or structure later develops. ...
The heart and lungs, from an older edition of Grays Anatomy. ...
Stage 10: 21-23 days In the development of vertebrate animals, the branchial arches (or pharyngeal arches) develop during the fourth and fifth week in utero as a series of mesodermal outpouchings on the left and right sides of the developing pharynx. ...
Intermediate mesoderm is a type of mesoderm that is located between the paraxial mesoderm and the lateral plate. ...
Stage 11: 23-26 days Sinus venosus can refer to: Another name for the embryological structure Sinus venarum A type of atrial septal defect This is a disambiguation page: a list of articles associated with the same title. ...
The Wolffian duct (also known as archinephric duct, Leydigs duct, and the mesonephric duct) is an organ found in humans during fetal development. ...
Stage 12: 26-30 days Stage 13: 28-32 days The cavity of the primitive atrium becomes subdivided into right and left chambers by a septum, the septum primum, which grows downward into the cavity. ...
Stage 14: 31-35 days The Ureteric bud is a portion of the mesonephric duct. ...
Stage 15: 35-38 days Stage 16: 36-42 days Stage 17: 42-44 days Stage 18: 44-48 days The septum secundum, semilunar in shape, grows downward from the upper wall of the atrium immediately to the right of the primary septum and foramen ovale. ...
Stage 19: 48-51 days Stage 20: 51-53 days Stage 21: 53-54 days Stage 22: 54-58 days Stage 23: 56-60 days See also Mammalian embryogenesis is the process of cell division and cellular differentiation which leads to the development of a mammalian embryo. ...
External links | v • d • e Mammalian development of embryo and development of fetus (some dates are approximate - see Carnegie stages) | | Week 1: Zygote - Morula - Blastula/Blastomere/Blastosphere - Archenteron/Primitive streak - Blastopore - Allantois - Trophoblast (Cytotrophoblast - Syncytiotrophoblast - Gestational sac) Week 2: Yolk sac - Vitelline duct - Bilaminar disc This article or section is in need of attention from an expert on the subject. ...
University of Lausanne, museum and library The University of Lausanne (in French: Université de Lausanne) or UNIL in Lausanne, Switzerland was founded in 1537 as a school of theology, before being made a university in 1890. ...
University of Berne The University of Berne is a university in the Swiss capital of Berne. ...
The University of Fribourg (French: Université de Fribourg; German: Universität Freiburg) is a university in the city of Fribourg, Switzerland. ...
The University of New South Wales or UNSW is a university situated in Kensington, a suburb in Sydney, New South Wales, Australia. ...
Mammalian embryogenesis is the process of cell division and cellular differentiation which leads to the development of a mammalian embryo. ...
This article or section is in need of attention from an expert on the subject. ...
It has been suggested that embryology be merged into this article or section. ...
Fetal (U.S. English; Foetal UK English) development is the process in which a fetus (U.S. English; Foetus UK English) develops during gestation, from the times of conception until birth. ...
Human fetus at eight weeks. ...
It has been suggested that Biparental zygote be merged into this article or section. ...
Morula is a stage of embryonic development in animals, including the 16-cell phase, the 32-cell phase, and the 64-cell phase. ...
Blastulation. ...
A blastomere is the structure which results from the divisions of a fertilised egg during embryonic development . ...
Blastulation. ...
The archenteron is an indentation that forms early on in a developing blastula. ...
The primitive streak is a structure that forms during the early stages of avian, reptilian and mammalian embryonic development. ...
A blastopore is an opening into the archenteron during the embryonic stages of an organism. ...
Allantois is a part of a developing animal embryo. ...
The trophoblast (from Greek threphein: to feed) is considered to be the first of all embryonic annexes. ...
The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ...
Syncytiotrophoblasts are cells found in the placenta of human embryos. ...
The gestational sac is the only available intrauterine structure that can be used to determine if an intrauterine pregnancy (IUP) exists, until the embryo is identified. ...
The yolk sac is the first element seen in the gestational sac during pregnancy, usually at 5 weeks gestation. ...
At the end of the fourth week the yolk-sac presents the appearance of a small pear-shaped vesicle (umbilical vesicle) opening into the digestive tube by a long narrow tube, the vitelline duct. ...
This article, image, template or category should belong in one or more categories. ...
Week 3: Hensen's node - Gastrula/Gastrulation - Trilaminar embryo Branchial arch (1st) - Branchial pouch - Meckel's cartilage - Somite/Somitomere - Sclerotome - Myotome - Germ layer (Ectoderm, Endoderm, Mesoderm, Chordamesoderm, Paraxial mesoderm, Intermediate mesoderm, Lateral plate mesoderm, Splanchnopleure, Somatopleure) Hensens Node is the organizer for gastrulation in birds. ...
1 - blastula, 2 - gastrula; orange - ectoderm, red - endoderm. ...
1 - blastula, 2 - gastrula; orange - ectoderm, red - endoderm. ...
It has been suggested that this article or section be merged with Embryogenesis. ...
In the development of vertebrate animals, the branchial arches (or pharyngeal arches) develop during the fourth and fifth week in utero as a series of mesodermal outpouchings on the left and right sides of the developing pharynx. ...
It has been suggested that this article or section be merged into branchial arch. ...
Pharyngeal or branchial pouches form on the endodermal side between the branchial arches, and pharyngeal grooves (or clefts) form from the lateral ectodermal surface of the neck region to separate the arches. ...
The cartilaginous bar of the mandibular arch is formed by what are known as Meckelâs cartilages (right and left) ; above this the incus is developed. ...
In the developing vertebrate embryo, somites are masses of mesoderm distributed along the two sides of the neural tube and that will eventually become dermis (dermatome), skeletal muscle (myotome), and vertebrae (sclerotome). ...
In the developing vertebrate embryo, the somitomeres are loose masses of paraxial mesoderm derived cells that form along each side of the neural tube towards the end of the third gestational week. ...
In vertebrate embryonic development, a group of embryonic tissues formed from somites that develop into the vertebrae. ...
In vertebrate embryonic development, a group of tissues formed from somites that develop into the body wall muscle. ...
Organs derived from each germ layer. ...
The ectoderm is outermost of the three germ layers of the developing embryo, the other two being the mesoderm and the endoderm. ...
The endoderm, sometimes refered to as entoderm, is one of the three germ layers of the developing embryo, the other two being the ectoderm and the mesoderm. ...
The mesoderm is one of the three germ layers in the early developing embryo, the other two layers being the ectoderm and the endoderm. ...
Chordamesoderm is a type of mesoderm that lies along the central axis, under the neural tube. ...
Paraxial mesoderm is the area of mesoderm that forms just lateral to the neural tube on both sides. ...
Intermediate mesoderm is a type of mesoderm that is located between the paraxial mesoderm and the lateral plate. ...
Lateral plate mesoderm (or hypomere) is a type of mesoderm that is found at the periphery of the embryo. ...
In the anatomy of an embryo, the splanchnopleure is a structure created during embryogenesis when the lateral mesoderm splits into two layers. ...
When the lateral mesoderm splits into two layers, the outer (or somatic) one becomes applied to the inner surface of the ectoderm, and with it forms the somatopleure. ...
Histogenesis and Organogenesis An Introduction to Histogenesis Histogenesis is defined as the formation of tissues and organs from undifferentiated cells (Encarta Dictionary). ...
Organogenesis is a stage of animal development where the ectoderm, endoderm, and mesoderm are formed. ...
Glands: Thyroglossal duct A gland is an organ in an animals body that synthesizes a substance for release such as hormones, often into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). ...
The thyroglossal duct is an embryological anatomical structure which forms the connection between the initial area of development of the thyroid gland and its final position. ...
Uterine support: Placenta - Umbilical cord (Umbilical artery, Umbilical vein, Wharton's jelly) - Amniotic sac (Amnion, Chorion) The uterus or womb is the major female reproductive organ of most mammals, including humans. ...
The placenta is an ephemeral (temporary) organ present in female placental vertebrates during gestation (pregnancy), but a placenta has evolved independently also in other animals as well, for instance scorpions and velvet worms. ...
In placental mammals, the umbilical cord is a tube that connects a developing embryo or fetus to its placenta. ...
Umbilical arteries carry deoxygenated blood from the fetus to the placenta in the umbilical cord. ...
Fetal circulation; the umbilical vein is the large, red vessel at the far left The umbilical vein is a blood vessel present during fetal development that carries oxygenated blood from the placenta to the growing fetus. ...
Whartons jelly is a gelatinous substance within the umbilical cord. ...
A drawing of the amniotic sac from Grays Anatomy. ...
For the alien race in Stephen Donaldsons The Gap Cycle, see Amnion (Gap Cycle). ...
For the entertainment company see Chorion (company) The chorion surrounds the embryo and other membranes. ...
Limb development: Limb bud - Apical Ectodermal Ridge/AER The vertebrate limb arises out of a general morphogenetic area called a limb field. ...
In embryology, the limb bud is a structure formed by the developing limb, derived from lateral plate mesoderm[citation needed]. It is intimately related with the apical ectodermal ridge, which secretes factors inducing the initial differentiation of the limb bud. ...
The Apical Ectodermal Ridge (AER) is a critical component in vertebrate limb development. ...
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