Template:Placenta terms: Difference between revisions
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* '''after-birth''' - term used to describe the delivery of placenta and placental membranes following birth of the child. | * '''after-birth''' - term used to describe the delivery of placenta and placental membranes following birth of the child. | ||
* '''allantois''' - An [[E#extraembryonic_membrane|extraembryonic membrane]], [[E#endoderm|endoderm]] in origin extension from the early hindgut, then cloaca into the connecting stalk of [[P#placenta|placental]] animals, connected to the superior end of developing bladder. In reptiles and birds, acts as a reservoir for wastes and mediates gas exchange. In mammals is associated/incorporated with connecting stalk/placental cord fetal-maternal interface. | * '''allantois''' - An [[E#extraembryonic_membrane|extraembryonic membrane]], [[E#endoderm|endoderm]] in origin extension from the early hindgut, then cloaca into the connecting stalk of [[P#placenta|placental]] animals, connected to the superior end of developing bladder. In reptiles and birds, acts as a reservoir for wastes and mediates gas exchange. In mammals is associated/incorporated with connecting stalk/placental cord fetal-maternal interface. | ||
* '''anastomosis''' - Term used to describe the connection between two tubes. Applied to describe the connection between peripheral blood vessels without an intervening capillary bed. | * '''anastomosis''' - Term used to describe the connection between two tubes. Applied to describe the connection between peripheral blood vessels without an intervening capillary bed. | ||
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* '''capsularis''' - portion of maternal decidua that covers the conceptus facing towards the uterine cavity. | * '''capsularis''' - portion of maternal decidua that covers the conceptus facing towards the uterine cavity. | ||
* '''chorioamnionitis''' - (CA) An intraamniotic puerperal infection described as having 3 forms: histologic, clinical (clinical chorioamnionitis, IAI), and subclinical. Intraamniotic infection is a common (2-4%) event in labor and the systemic inflammatory response can also lead to preterm birth and neonatal complications. | * '''chorioamnionitis''' - (CA) An intraamniotic puerperal infection described as having 3 forms: histologic, clinical (clinical chorioamnionitis, IAI), and subclinical. Intraamniotic infection is a common (2-4%) event in labor and the systemic inflammatory response can also lead to preterm birth and neonatal complications. | ||
* '''chorion''' - The [[E#extraembryonic_membrane|extraembryonic membrane]] generated from | * '''chorion''' - The [[E#extraembryonic_membrane|extraembryonic membrane]] generated from trophoblast and extraembryonic mesoderm that forms placenta. chorion and [[A#amnion|amnion]] are made by the somatopleure. The chorion becomes incorporated into placental development. The avian and reptilian chorion lies beside the egg shell and allows gas exchange. | ||
* '''chorionic cavity''' - The fluid-filled [[E#extraembryonic_coelom|extraembryonic coelom]] (cavity) formed initially from | * '''chorionic cavity''' - The fluid-filled [[E#extraembryonic_coelom|extraembryonic coelom]] (cavity) formed initially from trophoblast and extraembryonic mesoderm that forms placenta. chorion and [[A#amnion|amnion]] are made by the somatopleure. The chorion becomes incorporated into placental development. The avian and reptilian chorion lies beside the egg shell and allows gas exchange. In humans, this cavity is lost during week 8 when the [[A#amniotic cavity|amniotic cavity]] expands and fuses with the chorion. | ||
* '''chorion frondosum''' - (''frondosum'' = leafy) The chorion found on [[C#conceptus|conceptus]] oriented towards maternal blood supply where the majority of villi form and proliferate, will contribute the fetal component of the future | * '''chorion frondosum''' - (''frondosum'' = leafy) The chorion found on [[C#conceptus|conceptus]] oriented towards maternal blood supply where the majority of villi form and proliferate, will contribute the fetal component of the future placenta. | ||
* '''chorion laeve''' - (''laeve'' = smooth) The smooth chorion found on [[C#conceptus|conceptus]] away from maternal blood supply (towards uterine epithelium and cavity) with very few villi present. | * '''chorion laeve''' - (''laeve'' = smooth) The smooth chorion found on [[C#conceptus|conceptus]] away from maternal blood supply (towards uterine epithelium and cavity) with very few villi present. | ||
* '''chorionic gonadotropin''' - (CG, human chorionic gonadotropin, hCG) A hormone see [[H#human chorionic gonadotropin|human chorionic gonadotropin]]. | * '''chorionic gonadotropin''' - (CG, human chorionic gonadotropin, hCG) A hormone see [[H#human chorionic gonadotropin|human chorionic gonadotropin]]. | ||
* '''chorionic somatomammotropin''' - (CSH, human lactogen) A hormone synthesized within the | * '''chorionic somatomammotropin''' - (CSH, human lactogen) A hormone synthesized within the placenta by syncytiotrophoblast cells. This protein hormone (190 amino acid) has a structure is similar to pituitary growth hormone. | ||
* '''chorionic villus sampling''' - (CVS) The taking a biopsy of the | * '''chorionic villus sampling''' - (CVS) The taking a biopsy of the placenta, usually at the end of the second month of pregnancy, to test the fetus for genetic abnormalities. | ||
* '''coelocentesis''' - A sampling of extracoelomic fluid usually for an early prenatal diagnostic technique. | * '''coelocentesis''' - A sampling of extracoelomic fluid usually for an early prenatal diagnostic technique. | ||
* '''connecting stalk''' - the original extra-embryonic mesoderm structure attaching the embryonic disc to the chorion. The placental blood vessels form within this structure. | * '''connecting stalk''' - the original extra-embryonic mesoderm structure attaching the embryonic disc to the chorion. The placental blood vessels form within this structure. | ||
* '''cord blood''' - (human umbilical cord blood, HUCB) A term used to describe blood collected from the | |||
* '''cord blood''' - (human umbilical cord blood, HUCB) A term used to describe blood collected from the placenta usually after birth. Has been identified as a source of stem cells with potential therapeutic uses and is stored in Cord Blood Banks throughout the world. | |||
* '''cord knotting''' Term describing umbilical or placental cord knotting. This occurs in about 1% prevents the passage of placental blood, pseudoknots also occur usually with no effect. | * '''cord knotting''' Term describing umbilical or placental cord knotting. This occurs in about 1% prevents the passage of placental blood, pseudoknots also occur usually with no effect. | ||
* '''cord presentation''' - A term used to describe at birth the presence of the [[U#umbilical_cord|umbilical cord]] between the fetal presenting part and the [[C#cervix|cervix]], with or without membrane rupture. | * '''cord presentation''' - A term used to describe at birth the presence of the [[U#umbilical_cord|umbilical cord]] between the fetal presenting part and the [[C#cervix|cervix]], with or without membrane rupture. | ||
* '''cord prolapse''' - A term used to describe at birth the descent of the umbilical cord through the cervix alongside (occult) or past (overt) the presenting part in the presence of ruptured membranes (incidence of 0.1% to 0.6%). | * '''cord prolapse''' - A term used to describe at birth the descent of the umbilical cord through the cervix alongside (occult) or past (overt) the presenting part in the presence of ruptured membranes (incidence of 0.1% to 0.6%). | ||
* '''cotyledon''' - (Greek, ''kotyle'' = a deep cup) In the embryos of seed plants, the "seed leaves," in which nutrients are stored for use after germination. In placental animals, the term is also to describe the leaf-like structure of the | |||
* '''cytotrophoblast''' - The "cellular" | * '''cotyledon''' - (Greek, ''kotyle'' = a deep cup) In the embryos of seed plants, the "seed leaves," in which nutrients are stored for use after germination. In placental animals, the term is also to describe the leaf-like structure of the placenta surface. | ||
* '''decidua basalis''' - The term given to the uterine endometrium at the site of implantation where signaling transforms the uterine stromal cells (fibroblast-like) into decidual cells. This forms the maternal component of the | |||
* '''decidua basalis reaction''' - Term describing the maternal endometrial changes that occur initially at the site of, and following, blastocyst implantation. Seen as a deposition of glycogen, fibrin and proliferation of blood vessels. See also | * '''cytotrophoblast''' - The "cellular" trophoblast layer surrounding (forming a "shell") the early implanting [[C#conceptus|conceptus]]. Beginning at uterine adplantation, proliferation and fusion of these cells is thought to form a second outer trophoblast layer, the syncytiotrophoblast. The cytotrophoblast layer contributes to formation of the placental villi, the functional component of the fetal placenta. | ||
* '''decidua basalis''' - The term given to the uterine endometrium at the site of implantation where signaling transforms the uterine stromal cells (fibroblast-like) into decidual cells. This forms the maternal component of the placenta, the decidualization process gradually spreads through the remainder of the [[U#uterus|uterus]], forming the decidua parietalis. | |||
* '''decidua basalis reaction''' - Term describing the maternal endometrial changes that occur initially at the site of, and following, blastocyst implantation. Seen as a deposition of glycogen, fibrin and proliferation of blood vessels. See also decidualization. | |||
* '''decidua capsularis''' - The term given to the uterine endometrium which has been converted to decidua surrounding the conceptus on the smooth chorion side. | * '''decidua capsularis''' - The term given to the uterine endometrium which has been converted to decidua surrounding the conceptus on the smooth chorion side. | ||
* '''decidua parietalis''' - The term given to the remainder of the uterine [[E#endometrium|endometrium]], away from the site of [[I#implantation|implantation]], that gradually becomes comverted to [[D#decidua|decidua]]. | |||
* '''decidua parietalis''' - The term given to the remainder of the uterine [[E#endometrium|endometrium]], away from the site of [[I#implantation|implantation]], that gradually becomes comverted to [[D#decidua|decidua]]. | |||
* '''decidual cell''' - The uterine stromal cells (fibroblast-like) that differentiate in response to both steroid hormones (progesterone) and embryonic signals. These cells then alter uterine environment to support further embryonic development as well as producing cytokines related to prolactin (PRL) and have an innate immune function. | * '''decidual cell''' - The uterine stromal cells (fibroblast-like) that differentiate in response to both steroid hormones (progesterone) and embryonic signals. These cells then alter uterine environment to support further embryonic development as well as producing cytokines related to prolactin (PRL) and have an innate immune function. | ||
* '''decidualization''' - (decidualisation) The process by which uterine stromal cells differentiate in response to both steroid hormones and embryonic signals into large epitheliod decidual cells. This process is essential for the progress of implantation and establishing fetal-maternal communication. | * '''decidualization''' - (decidualisation) The process by which uterine stromal cells differentiate in response to both steroid hormones and embryonic signals into large epitheliod decidual cells. This process is essential for the progress of implantation and establishing fetal-maternal communication. | ||
* '''fetal drug addiction''' - occurs when drugs used maternally cross the placental barrier and can establish addiction in the unborn fetus. | * '''fetal drug addiction''' - occurs when drugs used maternally cross the placental barrier and can establish addiction in the unborn fetus. | ||
* '''fetal erythroblastosis''' - (Haemolytic Disease of the Newborn) A clinical term describing an immune response between fetal and maternal blood groups; from fetus Rh+ / maternal Rh-. The leakage of blood from fetus, particularly at birth, causes maternal anti-Rh antibodies, which is then dangerous for a 2nd or future pregnancies. | * '''fetal erythroblastosis''' - (Haemolytic Disease of the Newborn) A clinical term describing an immune response between fetal and maternal blood groups; from fetus Rh+ / maternal Rh-. The leakage of blood from fetus, particularly at birth, causes maternal anti-Rh antibodies, which is then dangerous for a 2nd or future pregnancies. | ||
* '''fibrinoid layer''' - ( | |||
* '''fibrinoid layer''' - (Nitabuch's layer) A layer formed at maternal/fetal interface during [[P#placenta|placentation]] and is thought to act to prevent excessively deep conceptus implantation. Fibrin-type fibrinoid (maternal blood-clot product) and matrix-type fibrinoid (secreted by invasive extravillous trophoblast cells). | |||
* '''floating chorionic villi''' - Term used to describe the placental microanatomy structure of [[C#chorionic villi|chorionic villi]] that '''are not''' attached to the maternal decidua and float in the maternal blood-filled space (lacunae). Structurally the same as [[A#anchoring chorionic villi|anchoring chorionic villi]] conceptus side that are attached to the maternal decidua.These villi go through the same stages of development: [[P#primary villi|primary]], [[S#secondary villi|secondary]] and [[T#tertiary villi|tertiary]] villi. | * '''floating chorionic villi''' - Term used to describe the placental microanatomy structure of [[C#chorionic villi|chorionic villi]] that '''are not''' attached to the maternal decidua and float in the maternal blood-filled space (lacunae). Structurally the same as [[A#anchoring chorionic villi|anchoring chorionic villi]] conceptus side that are attached to the maternal decidua.These villi go through the same stages of development: [[P#primary villi|primary]], [[S#secondary villi|secondary]] and [[T#tertiary villi|tertiary]] villi. | ||
* '''hemotrophic nutrition''' - Term used to describe in late | * '''hemotrophic nutrition''' - Term used to describe in late placenta development the transfer of blood-borne nutrition from maternal to embryo/fetuscompared to early histiotrophic nutrition. | ||
* '''histiotrophic nutrition''' - Term used to describe in early | |||
* '''histiotrophic nutrition''' - Term used to describe in early placenta development the intital transfer of nutrition from maternal to embryo (histiotrophic nutrition) compared to later blood-borne nutrition ([[H#hemotrophic_nutrition|hemotrophic nutrition]]). Histotroph is the nutritional material accumulated in spaces between the maternal and fetal tissues, derived from the maternal endometrium and the uterine glands. This nutritional material is absorbed by phagocytosis initially by blastocyst trophectoderm and then by trophoblast of the placenta. in later placental development nutrition is by the exchange of blood-borne materials between the maternal and fetal circulations, hemotrophic nutrition. | |||
* '''Hofbauer cells''' - Cells found within [[P#placenta|placental]] villi connective tissue. Have a role as macrophages of mesenchymal origin with potentially additional functions (remodeling, vasculogenesis, regulation of stromal water content). | * '''Hofbauer cells''' - Cells found within [[P#placenta|placental]] villi connective tissue. Have a role as macrophages of mesenchymal origin with potentially additional functions (remodeling, vasculogenesis, regulation of stromal water content). | ||
* '''Human chorionic corticotropin''' - (hCACTH) placental derived hormone equivilant to corticotropin (ACTH) from the pituitary. | * '''Human chorionic corticotropin''' - (hCACTH) placental derived hormone equivilant to corticotropin (ACTH) from the pituitary. | ||
* '''Human chorionic gonadotrophin''' - (hCG) like leutenizing hormone, supports corpus luteum, originally secreted by trophoblast cells. | * '''Human chorionic gonadotrophin''' - (hCG) like leutenizing hormone, supports corpus luteum, originally secreted by trophoblast cells. | ||
* '''Human chorionic somatommotropin ''' - (hCS, placental lactogen) hormone level increases in maternal blood through pregnancy, decreases maternal insulin sensitivity (raising maternal blood glucose levels and decreasing maternal glucose utilization) aiding fetal nutrition. | * '''Human chorionic somatommotropin ''' - (hCS, placental lactogen) hormone level increases in maternal blood through pregnancy, decreases maternal insulin sensitivity (raising maternal blood glucose levels and decreasing maternal glucose utilization) aiding fetal nutrition. | ||
* '''hydatiform mole''' - A uterine tumour with "grape-like" placenta appearance without enclosed | * '''hydatiform mole''' - A uterine tumour with "grape-like" placenta appearance without enclosed embryo formation, arises mainly from a haploid sperm fertilizing an egg without a female pronucleus. It is one form of gestational trophoblastic disease(GTD), a number of abnormalities including [[H#hydatiform mole|hydatiform mole]], invasive mole, choriocarcinoma and placental site trophoblastic tumor (PSTT). | ||
* '''hysterectomy''' – clinical term for the surgical removal of the uterus. | * '''hysterectomy''' – clinical term for the surgical removal of the uterus. | ||
* '''Langhans layer''' - cytotrophoblast cell layer. | * '''Langhans layer''' - cytotrophoblast cell layer. | ||
* '''maternal antibodies''' - antibodies from the mother's immune system that are capable of crossing placental barrier. They can provide immune protection to the embryo, but may also participate in immune disease (fetal erythroblastosis). | * '''maternal antibodies''' - antibodies from the mother's immune system that are capable of crossing placental barrier. They can provide immune protection to the embryo, but may also participate in immune disease (fetal erythroblastosis). | ||
* '''maternal sinusoids''' - placental spaces around chorionic villi that are filled with maternal blood. This is the closest maternal/fetal exchange site. | * '''maternal sinusoids''' - placental spaces around chorionic villi that are filled with maternal blood. This is the closest maternal/fetal exchange site. | ||
* '''Nitabuch's layer''' - ([[F#fibrinoid layer|fibrinoid layer]]) The layer formed at maternal/fetal interface during [[P#placenta|placentation]] and is thought to act to prevent excessively deep conceptus [[I#implantation|implantation]]. Fibrin-type fibrinoid (maternal blood-clot product) and matrix-type fibrinoid (secreted by invasive extravillous | |||
* '''Nitabuch's layer''' - ([[F#fibrinoid layer|fibrinoid layer]]) The layer formed at maternal/fetal interface during [[P#placenta|placentation]] and is thought to act to prevent excessively deep conceptus [[I#implantation|implantation]]. Fibrin-type fibrinoid (maternal blood-clot product) and matrix-type fibrinoid (secreted by invasive extravillous trophoblast cells). | |||
* '''Morbidly adherent placenta''' (MAP) A general clinical term used to describe the different forms of abnormal placental implantation (Accreta, Increta and Percreta). | * '''Morbidly adherent placenta''' (MAP) A general clinical term used to describe the different forms of abnormal placental implantation (Accreta, Increta and Percreta). | ||
* '''persistent right umbilical vein''' - (PRUV) A placental cord abnormality associated with fetal abnormalities and poor neonatal prognosis. The estimated incidence of persistent right umbilical vein in a low-risk population is 1 : 526. [http://www.ncbi.nlm.nih.gov/pubmed/12047534 PMID | |||
* '''oligohydramnios''' - Clinical term for the accumulation a deficiency of amniotic fluid during pregnancy. See also polyhydramnios, an excess of amniotic fluid. | |||
* '''persistent right umbilical vein''' - (PRUV) A placental cord abnormality associated with fetal abnormalities and poor neonatal prognosis. The estimated incidence of persistent right umbilical vein in a low-risk population is 1 : 526. [http://www.ncbi.nlm.nih.gov/pubmed/12047534 PMID 12047534] | |||
* '''polyhydramnios''' - Clinical term for the accumulation of excess amniotic fluid during pregnancy. See also oligohydramnios, a deficiency of amniotic fluid. | |||
* '''placenta''' - (Greek, ''plakuos'' = flat cake) The developmental organ formed from maternal and fetal contributions in animals with placental development. In human, the placenta at term is a discoid shape "flat cake" shape; 20 cm diameter, 3 cm thick and weighs 500-600 gm. Placenta are classified by the number of layers between maternal and fetal blood (Haemochorial, Endotheliochorial and Epitheliochorial) and shape (Discoid, Zonary, Cotyledenary and Diffuse). The placenta has many different functions including metabolism, transport and endocrine. | * '''placenta''' - (Greek, ''plakuos'' = flat cake) The developmental organ formed from maternal and fetal contributions in animals with placental development. In human, the placenta at term is a discoid shape "flat cake" shape; 20 cm diameter, 3 cm thick and weighs 500-600 gm. Placenta are classified by the number of layers between maternal and fetal blood (Haemochorial, Endotheliochorial and Epitheliochorial) and shape (Discoid, Zonary, Cotyledenary and Diffuse). The placenta has many different functions including metabolism, transport and endocrine. | ||
* '''placenta accreta''' - The abnormal placental adherence, either in whole or in part of the | |||
* '''placental arteries''' - ( | * '''placenta accreta''' - The abnormal placental adherence, either in whole or in part of the placenta with absence of decidua basalis, leading to retention as an after-birth to the underlying uterine wall. The incidence of placenta accreta also significantly increases in women with previous cesarean section compared to those without a prior surgical delivery. | ||
* '''placental cord''' - ( | |||
* '''placental arteries''' - (umbilical arteries) In placental animals, the blood vessels which develop within the placental cord carrying relatively deoxygenated blood from the embryo/fetus to the placenta. In humans, there are two placental arteries continuous with the paired internal iliac arteries (hypogastric arteries) arising off the [[D#dorsal aorta|dorsal aortas]]. At birth this vessel regresses and form the remnant medial umbilical ligament. | |||
* '''placental cord''' - (umbilical cord) The placental cord is the structure connecting the embryo/fetus to the placenta. It is initially extra-embryonic mesoderm forming the connecting stalk within which the placental blood vessels (arteries and veins) form. In human placental cords the placental blood vessels are initially paired, later in development only a single placental vein remains with a pair of placental arteries. This structure also contains the allantois, an extension from the hindgut cloaca then urogenital sinus. Blood collected from the placental cord following delivery is a source of cord blood stem cells.) | |||
* '''placental diameter''' - is measured in the transverse section by calculating the maximum dimensions of the chorionic surface. | * '''placental diameter''' - is measured in the transverse section by calculating the maximum dimensions of the chorionic surface. | ||
* '''placental growth factor''' - ([[#PlGF|PlGF]]) A growth factor of the vascular endothelial growth factor (VEGF) family, released from the placental | |||
* '''placental malaria''' - The malarial infection of the | * '''placental growth factor''' - ([[#PlGF|PlGF]]) A growth factor of the vascular endothelial growth factor (VEGF) family, released from the placental trophoblast cells and other sources that stimulates blood vessel growth. | ||
* '''placental malaria''' - The malarial infection of the placenta by sequestration of the infected red blood cells. This condition can be common in regions where malaria is endemic with women carrying their first pregnancy ([[P#primigravida|primigravida]]). | |||
* '''placental membranes''' - [[C#chorionic membrane|chorionic membrane]] [[A#amniotic membrane]]) General term to describe the membrane bound extra-embryonic fluid-filled cavities surrounding the embryo then fetus. In humans the [[A#amniotic membrane]] and [[C#chorionic membrane|chorionic membrane]] fuse. | * '''placental membranes''' - [[C#chorionic membrane|chorionic membrane]] [[A#amniotic membrane]]) General term to describe the membrane bound extra-embryonic fluid-filled cavities surrounding the embryo then fetus. In humans the [[A#amniotic membrane]] and [[C#chorionic membrane|chorionic membrane]] fuse. | ||
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* '''placenta percreta''' - abnormal placentation where the villi penetrate myometrium. | * '''placenta percreta''' - abnormal placentation where the villi penetrate myometrium. | ||
* '''placenta previa''' - placenta overlies internal os of uterus, abnormal bleeding, may require cesarian delivery. | * '''placenta previa''' - placenta overlies internal os of uterus, abnormal bleeding, may require cesarian delivery. | ||
* '''placental thickness''' - is measured at its mid-portion from the chorionic plate to the basilar plate, on a longitudinal plane (less than 4 cm at term). Excludes any abnormalities (fibroids, myometrial contractions, or venous lakes). The placental thickness approximates in millimeters to the weeks of gestation. | * '''placental thickness''' - is measured at its mid-portion from the chorionic plate to the basilar plate, on a longitudinal plane (less than 4 cm at term). Excludes any abnormalities (fibroids, myometrial contractions, or venous lakes). The placental thickness approximates in millimeters to the weeks of gestation. | ||
* '''placental vein''' - ([[U#umbilical vein|umbilical vein]]) In placental animals, the blood vessels which develop within the placental cord carrying relatively oxygenated blood from the | * '''placental vein''' - ([[U#umbilical vein|umbilical vein]]) In placental animals, the blood vessels which develop within the placental cord carrying relatively oxygenated blood from the placenta to the embryo/fetus. In humans, there are initially two placental veins which fuse to form a single vein. The resence of paired veins in the placental cord can be indicative of developmental abnormalities. | ||
* '''placentophagia''' - Term used to descrbe the maternal ingestion of afterbirth materials (placental membranes and amniotic fluid) that can occur following mammalian parturition (birth). | * '''placentophagia''' - Term used to descrbe the maternal ingestion of afterbirth materials (placental membranes and amniotic fluid) that can occur following mammalian parturition (birth). | ||
* '''primary villi''' - (primary chorionic villi) Term describing the earliest stage of embryonic placenta development. In humans, the conceptus during week 2 this first stage of [[C#chorion|chorionic]] villi development consists of only the [[T#trophoblast|trophoblastic shell cells]] ([[S#syncitiotrophoblast|syncitiotrophoblasts]] and [[C#cytotrophoblast|cytotrophoblasts]]) forming finger-like extensions into maternal decidua. Initially these finger-like projections cover the entire surface of chorionic sac and later become restricted to the placental surface. The villi stages are ongoing as the placenta continues to grow through both the embryonic and fetal development. | * '''primary villi''' - (primary chorionic villi) Term describing the earliest stage of embryonic placenta development. In humans, the conceptus during week 2 this first stage of [[C#chorion|chorionic]] villi development consists of only the [[T#trophoblast|trophoblastic shell cells]] ([[S#syncitiotrophoblast|syncitiotrophoblasts]] and [[C#cytotrophoblast|cytotrophoblasts]]) forming finger-like extensions into maternal decidua. Initially these finger-like projections cover the entire surface of chorionic sac and later become restricted to the placental surface. The villi stages are ongoing as the placenta continues to grow through both the embryonic and fetal development. | ||
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* '''vasculogenesis''' - formation of first blood vessels by differentiation of pluripotent mesenchymal cells (extraembryonic mesoderm) followed by angiogenesis which is the development of new vessels from already existing vessels. | * '''vasculogenesis''' - formation of first blood vessels by differentiation of pluripotent mesenchymal cells (extraembryonic mesoderm) followed by angiogenesis which is the development of new vessels from already existing vessels. | ||
* '''villi''' - Plural of villus, which is a thin projection from a surface. The term in development is used to describe the individual functional units together of the fetal | * '''villi''' - Plural of villus, which is a thin projection from a surface. The term in development is used to describe the individual functional units together of the fetal placenta. | ||
* '''virus''' - small infectious agents that may cross the placental barrier. Can infect embryo and/or placenta and cause developmental abnormalities. (e.g. cytomegalovirus, rubella, measles). | * '''virus''' - small infectious agents that may cross the placental barrier. Can infect embryo and/or placenta and cause developmental abnormalities. (e.g. cytomegalovirus, rubella, measles). |
Revision as of 17:11, 4 April 2018
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