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The placenta (Latin for cake, referencing its appearance in humans) is an ephemeral organ present in placental vertebrates, such as eutherial mammals and sharks during gestation (pregnancy). Protherial (egg-laying) and metatherial (marsupial) mammals do not produce a placenta. The placenta develops from the same sperm and egg cells that form the fetus, and functions as a foetomaternal organ with two components, the foetal part (Chorion frondosum), and the maternal part (Decidua basailis). Image File history File links Broom_icon. ...
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Decidua is the term for the uterine lining (endometrium) during a pregnancy that forms the maternal part of the placenta. ...
For the entertainment company see Chorion (company). ...
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For the kind of film, see ephemeral film. ...
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Orders Superorder Xenarthra: Pilosa Cingulata Infraclass Epitheria: Superorder Afrotheria: Afrosoricida (Golden mole and tenrec) Macroscelidea (Elephant shrew) Tubulidentata (Aardvark) Hyracoidea (Hyrax) Proboscidea (Elephant) Sirenia (Manatee, Dugong) Superorder Laurasiatheria: Chiroptera (Bats) Insectivora (Shrews, Moles) Cetacea (Whale, dolphin) Artiodactyla (Ruminants et al) Perissodactyla(Horse et al. ...
Typical classes Petromyzontidae (lampreys) Placodermi - extinct Chondrichthyes (cartilaginous fish) Acanthodii - extinct Actinopterygii (ray-finned fish) Actinistia (coelacanths) Dipnoi (lungfish) Amphibia (amphibians) Reptilia (reptiles) Aves (birds) Mammalia (mammals) Vertebrata is a subphylum of chordates, specifically, those with backbones or spinal columns. ...
Orders[1] Bobolestes Eomaia Maelestes Montanalestes Murtoilestes Prokennalestes Placentalia Superorder Xenarthra: Cingulata (Armadillos) Pilosa (Sloths, True Anteaters) Superorder Afrotheria: Afrosoricida (Tenrecs, etc. ...
Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the presence of sweat glands, including milk producing sweat glands, and by the presence of: hair, three middle ear bones used in hearing, and a neocortex...
For other uses, see Shark (disambiguation). ...
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. ...
This article is about human pregnancy in biological females. ...
Metatheria is a grouping within the animal class Mammalia. ...
Structure
Functions For nine months the placenta feeds and nourishes the fetus while also disposing of toxic waste. Without it the baby could not survive. After the baby is born, the placenta no longer serves a function.
Among organs, it is unique. It is the only organ in the human body that serves a vital function and then becomes obsolete.
Filtration and transfer The placenta receives nutrients, oxygen, antibodies, and hormones from the mother's blood, and passes out waste. It forms a barrier (called the "placental barrier"), which filters out some substances that could harm the fetus. The placental barrier does not allow the blood from the mother and the blood from the embryo to mix, in order to avoid the possible transfusion of different blood types. However, many substances are not filtered out, including alcohol, all anesthesiatic drugs used in medical childbirth (opioids and cocaine derivatives), and some chemicals associated with smoking cigarettes. Several types of viruses, such as Human Cytomegalovirus, may also cross this barrier; this often leads to various degrees of birth defects in the infant. For other uses, see Blood (disambiguation). ...
This article does not cite any references or sources. ...
Anesthesia or anaesthesia (see spelling differences) has traditionally meant the condition of having the perception of pain and other sensations blocked. ...
A cigarette will burn to ash on one end. ...
This article is about biological infectious particles. ...
Species see text Cytomegalovirus (CMV) (from the Greek cyto-, cell, and -mega-, large) is a viral genus of the Herpesviruses group: in humans it is commonly known as human herpesvirus 5 (HHV-5). ...
A congenital disorder is a medical condition or defect that is present at or before birth (for example, congenital heart disease). ...
Placental circulation
Maternal placental circulation The Maternal blood enters the intervillous space through endometrial arteries (spiral arteries), 80 to 100 in number. They pierce the decidual plate and then pass through the gaps in cytotrophoblastic shell. As the artery enters, it is under high pressure because it enters through the small gap; this pressure forces the blood deep into intervillous spaces and bathes the villi. Exchange of gases takes place. As the pressure decreases, the deoxygenated blood flows backwards to the decidua and enters the endometrial veins. The trophoblast proliferates rapidly and forms a network of branching processes which cover the entire ovum and invade and destroy the maternal tissues and open into the maternal bloodvessels, with the result that the spaces in the trophoblastic network are filled with maternal blood; these spaces communicate freely with one...
Endometrial arteries are those arteries that enter the endometrium to supply nutrition and oxygen to the fetus Category: ...
Fetoplacental circulation Deoxygenated fetal blood passes through umbilical arteries to placenta. At the junction of umbilical cord and placenta, the umbilical arteries branch radially to form chorionic arteries. Chorionic arteries also branch before they enter into the villi. In the villi, they form an extensive arteriocapillary venous system, bringing the fetal blood extremely close to the maternal blood; but normally no intermingling of fetal and maternal blood occurs.
Metabolic and endocrine activity In addition to the transfer of gases and nutrients, the placenta also has metabolic and endocrine activity. It produces, among other hormones, progesterone, which is important in maintaining the pregnancy; somatomammotropin (also known as placental lactogen), which acts to increase the amount of glucose and lipids in the maternal blood; estrogen; relaxin, and human chorionic gonadotrophin (hCG). This results in increased transfer of these nutrients to the fetus and is also the main cause of the increased blood sugar levels seen in pregnancy. The hormone HCG (human chorionic gonadotrophin) ensures that progesterone and oestrogen is still being secreted as these hormones make sure the uterus lining is developing and is a good environment for the foetus. However after about 2 months the placenta takes on the role of producing progesterone and therefore HCG is no longer needed. HCG is excreted in urine and this is how pregnancy tests work. Major endocrine glands. ...
Hormone is also the NATO reporting name for the Soviet/Russian Kamov Ka-25 military helicopter. ...
Progesterone is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy (supports gestation) and embryogenesis of humans and other species. ...
Also called human placental lactogen, somatomammotropin is an important hormone of pregnancy. ...
Estriol. ...
Categories: Possible copyright violations ...
Human chorionic gonadotropin (hCG) is a peptide hormone produced in pregnancy, that is made by the embryo soon after conception and later by the trophoblast (part of the placenta). ...
Materno-foetal circulation passes through the duct of Smith-Bessant before crossing the laura-brain barrier.
Parasitic cloaking from immune system of mother To hide itself from the mother's immune system the placenta secretes Neurokinin B containing phosphocholine molecules. This is the same mechanism used by the parasitic nematode to avoid detection by the immune system of its host.[1] Neurokinin B is a tachykinin peptide. ...
Phosphocholine (PC) is an intermediate in the synthesis of phosphatidylcholine in tissues. ...
A parasite is an organism that lives in or on the living tissue of a host organism at the expense of it. ...
Classes Adenophorea Subclass Enoplia Subclass Chromadoria Secernentea Subclass Rhabditia Subclass Spiruria Subclass Diplogasteria Subclass Tylenchia The nematodes or roundworms (Phylum nematoda from Greek (nema): thread + -ode like) are one of the most common phyla of animals, with over 80,000 different described species (over 15,000 are parasitic). ...
Birth When the fetus is born, its placenta begins a physiological separation for spontaneous expulsion afterwards (and for this reason is often called the afterbirth). The umbilical cord is routinely clamped and severed prior to the delivery of the placenta, often within seconds or minutes of birth, a medical protocol known as 'active management of third stage' which has been called into question by advocates of natural birth and 'passive management of third stage'[2] The site of the former umbilical cord attachment in the center of the front of the abdomen is known as the umbilicus, navel, or belly-button. In placental mammals, the umbilical cord is a tube that connects a developing embryo or fetus to the placenta. ...
For the human abdomen, see human abdomen. ...
This article or section does not cite its references or sources. ...
Modern obstetric practice has decreased maternal death rates enormously. The addition of active management of the third stage of labor is a major contributor towards this. It involves giving oxytocin via IM injection, followed by cord traction to assist in delivering the placenta. Premature cord traction can pull the placenta before it has naturally detached from the uterine wall, resulting in hemorrhage. The BMJ summarized the Cochrane group metanalysis (2000) of the benefits of active third stage as follows: Oxytocin (Greek: quick birth) is a mammalian hormone that also acts as a neurotransmitter in the brain. ...
The British Medical Journal (BMJ) is a medical journal published weekly in the United Kingdom by the British Medical Association (BMA)which published its first issue in 1845. ...
"One systematic review found that active management of the third stage of labour, consisting of controlled cord traction, early cord clamping plus drainage, and a prophylactic oxytocic agent, reduced postpartum haemorrhage of 500 or 1000 mL or greater and related morbidities including mean blood loss, postpartum haemoglobin less than 9 g/dL, blood transfusion, need for supplemental iron postpartum, and length of third stage of labour. Although active management increased adverse effects such as nausea, vomiting, and headache, one RCT identified by the review found that women were less likely to be dissatisfied when their third stage of labour was actively managed."[1] Risks of retained placenta include hemorrhage and infection. If the placenta fails to deliver in 30 minutes in a hospital environment, manual extraction may be required if heavy ongoing bleeding occurs, and very rarely a curettage is necessary to ensure that no remnants of the placenta remain (in rare conditions with very adherent placenta (placenta accreta)). However, in birth centers and attended home birth environments, it is common for licensed care providers to wait for the placenta's birth up to 2 hours in some instances. In surgery, the use of a curette to remove tissue by scraping or scooping. ...
Non-humans In most mammalian species, the mother bites through the cord and consumes the placenta, primarily for the benefit of prostaglandin on the uterus after birth. This is known as placentophagy. However, it has been observed in zoology that chimpanzees, with which humans share 99% of genetic material, apply themselves to nurturing their offspring, and keep the fetus, cord, and placenta intact until the cord dries and detaches the next day. E1 - Alprostadil I2 - Prostacyclin A prostaglandin is any member of a group of lipid compounds that are derived enzymatically from fatty acids and have important functions in the animal body. ...
Mother goat eating placenta Rat eating its offsprings placenta after birth Placentophagy (from placenta + Greek φαγειν, to eat) is the act of mammals eating the placenta of their young after childbirth. ...
 Top: Human placenta shown a few minutes after birth. The side shown faces the baby with the umbilical cord top right. The white fringe surrounding the bottom is the remnants of the amniotic sac. Bottom: A different placenta displays side that connects to the uterine wall. Image File history File linksMetadata Size of this preview: 397 × 600 pixelsFull resolution (1200 × 1813 pixel, file size: 365 KB, MIME type: image/jpeg) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
Image File history File linksMetadata Size of this preview: 397 × 600 pixelsFull resolution (1200 × 1813 pixel, file size: 365 KB, MIME type: image/jpeg) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
In placental mammals, the umbilical cord is a tube that connects a developing embryo or fetus to the placenta. ...
A drawing of the amniotic sac from Grays Anatomy. ...
This article is about female reproductive anatomy. ...
Pathology See: Placenta accreta is a severe obstetric complication involving an abnormal attachment of the placenta to the myometrium (the middle layer of the uterine wall). ...
Placental abruption (Also known as abruptio placentae) is a complication of pregnancy, wherein the placental lining has separated from the uterus of the mother. ...
Cultural practices and beliefs The placenta often plays an important role in various human cultures, with many societies conducting rituals regarding its disposal. In the Western world, the placenta is most often incinerated.[3] For other uses, see Culture (disambiguation). ...
Occident redirects here. ...
Incineration is the process of burning waste streams under controlled industrial conditions. ...
Some cultures bury the placenta for various reasons. The Māori of New Zealand traditionally bury the placenta from a newborn child to emphasize the relationship between humans and the earth.[4] Similarly, the Navajo bury the placenta and umbilical cord at a specially-chosen site,[5] particularly if the baby dies during birth.[6] In Cambodia and Costa Rica, burial of the placenta protects and ensures the health of the baby and the mother.[7] If a mother dies in childbirth, the Aymara of Bolivia bury the placenta in a secret place so that the mother's spirit will not return to claim her baby's life.[8] This article needs additional references or sources for verification. ...
This article is about the MÄori people of New Zealand. ...
For other uses, see Navajo (disambiguation). ...
The Aymara are a native ethnic group in the Andes region of South America; about 2. ...
The placenta is believed by some communities to have power over the lives of the baby or its parents. The Kwakiutl of British Columbia bury girls' placentas to give the girl skill in digging clams, and expose boys' placentas to ravens to encourage future prophetic visions. In Turkey, the proper disposal of the placenta and umbilical cord is believed to promote devoutness in the child later in life. In Ukraine, Transylvania, and Japan, interaction with a disposed placenta is thought to influence the parents' future fertility. The ancient Egyptians believed that the placenta was imbued with magical powers.[7] bye Until the 1980s the term Kwakiutl was usually applied to all of the various First Nations peoples of northern Vancouver Island, Queen Charlotte Strait and the Johnstone Strait whose traditional Wakashan language was Kwakwala and also a group of peoples erroneously called for many years the Northern Kwakiutl...
Motto: Splendor sine occasu (Latin: Splendour without diminishment) Capital Victoria Largest city Vancouver Official languages English (de facto) Government Lieutenant-Governor Steven Point Premier Gordon Campbell (BC Liberal) Federal representation in Canadian Parliament House seats 36 Senate seats 6 Confederation July 20, 1871 (6th province) Area Ranked 5th Total 944...
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For other senses of this word, see Prophet (disambiguation). ...
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Khafres Pyramid and the Great Sphinx of Giza, built about 2550 BC during the Fourth Dynasty of the Old Kingdom,[1] are enduring symbols of the civilization of ancient Egypt Ancient Egypt was a civilization in Northeastern Africa concentrated along the middle to lower reaches of the Nile River...
Several cultures believe the placenta to be or have been alive, often a relative of the baby. Nepalese think of the placenta as a friend of the baby's; Malaysians regard it as the baby's older sibling. The Ibo of Nigeria and Ghana consider the placenta the deceased twin of the baby, and conduct full funeral rites for it.[7] Native Hawaiians believe that the placenta is a part of the baby, and traditionally plant it with a tree which can then grow alongside the child.[3] IBO can stand for: Independent Business Owner - an owner of a franchise, especially in a multi-level marketing business. ...
Hawaiian could refer to the Hawaiian language the native Hawaiian people within Hawaii. ...
In some cultures, the placenta is eaten, a practice known as placentophagy. Placenta can be eaten fried, grilled or even microwaved. Mother goat eating placenta Rat eating its offsprings placenta after birth Placentophagy (from placenta + Greek φαγειν, to eat) is the act of mammals eating the placenta of their young after childbirth. ...
Additional images Fetus of about eight weeks, enclosed in the amnion. Magnified a little over two diameters. Image File history File links Gray30. ...
| Picture of freshly delivered placenta and umbillical cord |
See also For other uses, see Embryo (disambiguation). ...
Parturition redirects here. ...
This article is about female reproductive anatomy. ...
References - ^ Placenta 'fools body's defences'. BBC News (2007-11-10).
- ^ http:www.sarahjbuckley.com/articles/leaving-well-alone.htm
- ^ a b "Why eat a placenta?", BBC, 2006-04-18. Retrieved on 2008-01-08.
- ^ Metge, Joan. 2005. "Working in/Playing with three languages: English, Te Reo Maori, and Maori Bod Language." In Sites N.S vol. 2, No 2:83-90.
- ^ Francisco, Edna (2004-12-03). Bridging the Cultural Divide in Medicine. Minority Scientists Network. Retrieved on 2008-01-07.
- ^ Shepardson, Mary (1978). Changes in Navajo Mortuary Practices and Beliefs. American Indian Quarterly. University of Nebraska Press. Retrieved on 2008-01-07.
- ^ a b c Buckley, Sarah J.. Placenta Rituals and Folklore from around the World. Mothering. Retrieved on 2008-01-07.
- ^ Davenport, Ann (June 2005). The Love Offer. Johns Hopkins Magazine. Retrieved on 2008-01-07.
Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ...
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2008 (MMVIII) will be a leap year starting on Tuesday of the Anno Domini (common) era, in accordance with the Gregorian calendar. ...
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2008 (MMVIII) will be a leap year starting on Tuesday of the Anno Domini (common) era, in accordance with the Gregorian calendar. ...
is the 7th day of the year in the Gregorian calendar. ...
2008 (MMVIII) will be a leap year starting on Tuesday of the Anno Domini (common) era, in accordance with the Gregorian calendar. ...
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External links Wikimedia Commons has media related to: - Additional Human placenta photography [2]
| Developmental biology > Human embryogenesis (development of embryo) and development of fetus (some dates are approximate - see Carnegie stages and a timeline) | | Week 1 | Fertilization - Egg activation - Zygote - Cleavage - Morula - Blastula (Blastomere) - Blastocyst - Inner cell mass | | Week 2 | Bilaminar disc (Hypoblast, Epiblast) | Week 3 (Trilaminar embryo,
germ layers) | Archenteron/Primitive streak (Primitive pit, Primitive knot/Blastopore, Primitive groove) - Gastrula/Gastrulation - Regional specification Ectoderm: Surface ectoderm - Neuroectoderm - Somatopleure - Neurulation - Neural crest Image File history File links Commons-logo. ...
Views of a Foetus in the Womb, Leonardo da Vinci, ca. ...
Human embryogenesis is the process of cell division and cellular differentiation of the human embryo during early prenatal development. ...
This article or section is in need of attention from an expert on the subject. ...
For other uses, see Embryo (disambiguation). ...
This article is about prenatal development in humans. ...
For other uses, see Fetus (disambiguation). ...
This article does not cite any references or sources. ...
The following list describes a timeline of specific changes in human prenatal development by week of gestational age. ...
This article is about fertilisation in animals and plants. ...
After the fusion of the sperm plasma membrane and the egg plasma membrane after fertilization, animal eggs go through a process called egg activation to prepare the egg for development. ...
It has been suggested that Biparental zygote be merged into this article or section. ...
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. ...
Blastulation. ...
A blastomere is the structure which results from the divisions of a fertilised egg during embryonic development . ...
The blastocyst is an early stage of the human (or any other mammal) development early in pregnancy. ...
The inner cell mass is surrounded by the single cell layer of cells called trophoblast. ...
This article, image, template or category should belong in one or more categories. ...
The hypoblast is a tissue type from the inner cell mass. ...
In embryology, the epiblast is a feature present during gastrulation. ...
It has been suggested that this article or section be merged with Embryogenesis. ...
Organs derived from each germ layer. ...
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. ...
The primitive pit is a depression in the center of the primitive node, connecting to the notochord. ...
The primitive knot (or Primitive node) is the organizer for gastrulation in vertebrates. ...
A blastopore is an opening into the archenteron during the embryonic stages of an organism. ...
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. ...
1 - blastula, 2 - gastrula; orange - ectoderm, red - endoderm. ...
It has been suggested that epiboly be merged into this article or section. ...
Regional specification is the process by which different areas are identified in the development of the early embryo. ...
The ectoderm is outermost of the three germ layers of the developing embryo, the other two being the mesoderm and the endoderm. ...
The surface ectoderm (or external ectoderm forms the following structures: Skin(only epidermis;as dermis is derived from mesoderm) (along with glands, hair, nail (anatomy)) Epithelium of the mouth and nasal cavity saliavary glands, and glands of mouth and nasal cavity Enamel (in teeth) - as a side note dentin and...
Neuroectoderm is the term for ectoderm which receives inhibitory signals from proteins such as noggin, which leads to the development of the nervous system from this tissue. ...
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. ...
Neurulation is a part of organogenesis in vertebrate embryos. ...
The neural crest, a component of the ectoderm, is one of several ridgelike clusters of cells found on either side of the neural tube in vertebrate embryos. ...
Endoderm: Splanchnopleure Endoderm is one of the germ layers formed during animal embryogenesis. ...
In the anatomy of an embryo, the splanchnopleure is a structure created during embryogenesis when the lateral mesoderm splits into two layers. ...
Mesoderm: Chorda- - Paraxial (Somite/Somitomere/Sclerotome/Myotome/Dermatome) -
Intermediate - Lateral plate (Intraembryonic coelom, Splanchnopleure/Somatopleure) | | Extraembryonic/uterus | Trophoblast (Cytotrophoblast, Syncytiotrophoblast) Blastocoele - Yolk sack/exocoelomic cavity - Heuser's membrane - Extraembryonic coelom - Vitelline duct 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. ...
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. ...
The cutis plate is the dorsal portion of the paraxial mesoderm somite which gives rise to dermis. ...
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. ...
The intraembryonic coelom (or somatic coelom) is a a portion of the conceptus forming in the mesoderm. ...
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. ...
This article is about female reproductive anatomy. ...
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. ...
A blastocoel(e) or blastocele or cleavage cavity or segmentation cavity is the central region of a blastocyst. ...
The yolk sac is the first element seen in the gestational sac during pregnancy, usually at 5 weeks gestation. ...
Heusers membrane (or the exocoelomic membrane) is a short lived combination of hypoblast cells and extracellular matrix. ...
The extraembryonic coelom is a portion of the conceptus consisting of a cavity between Heusers membrane and the hypoblast. ...
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. ...
Umbilical cord (Umbilical artery, Umbilical vein, Wharton's jelly) - Allantois In placental mammals, the umbilical cord is a tube that connects a developing embryo or fetus to the 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. ...
Allantois is a part of a developing animal embryo. ...
Placenta - Decidua (Decidual cells) - Chorionic villi/Intervillous space - Gestational sac (Amnion/Amniotic sac/Amniotic cavity, Chorion) | | Histogenesis | Programmed cell death - Stem cells - Germ line development | | Organogenesis | Limb development: Limb bud - Apical ectodermal ridge/AER
other structures: Eye development - Cutaneous structure development - Heart development - Development of the urinary and reproductive organs | | Human anatomy, endocrine system: endocrine glands | | Hypothalamic/pituitary axes | Adrenal axis: Adrenal gland Thyroid axis: Thyroid gland (Parafollicular cell, Thyroid epithelial cell, Thyroid isthmus) - Parathyroid gland (Oxyphil cell, Chief cell) Decidua is the term for the uterine lining (endometrium) during a pregnancy. ...
Before the fertilized ovum reaches the uterus, the mucous membrane of the body of the uterus undergoes important changes and is then known as the decidua. ...
Chorionic villi are villi that sprout from the chorion, in order to give a maximum area of contact with the maternal blood. ...
The trophoblast proliferates rapidly and forms a network of branching processes which cover the entire ovum and invade and destroy the maternal tissues and open into the maternal bloodvessels, with the result that the spaces in the trophoblastic network are filled with maternal blood; these spaces communicate freely with one...
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. ...
For the alien race in Stephen Donaldsons The Gap Cycle, see Amnion (Gap Cycle). ...
A drawing of the amniotic sac from Grays Anatomy. ...
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. ...
For the entertainment company see Chorion (company) The chorion surrounds the embryo and other membranes. ...
An Introduction to Histogenesis Histogenesis is defined as the formation of tissues and organs from undifferentiated cells (Encarta Dictionary). ...
Programmed cell death (PCD) is the deliberate suicide of an unwanted cell in a multicellular organism. ...
Mouse embryonic stem cells. ...
The cells that give rise to the gametes are often set aside during cleavage. ...
Organogenesis is a stage of animal development where the ectoderm, endoderm, and mesoderm are formed. ...
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. ...
Transverse section showing the lens and the optic cup. ...
Cutaneous structures arise from the epidermis and include a variety of features such as hair, feathers, claws and nails. ...
The heart is the first functional organ in a vertebrate embryo. ...
In prenatal development, the urinary and reproductive organs are developed from the intermediate mesoderm. ...
List of bones of the human skeleton Human anatomy is primarily the scientific study of the morphology of the adult human body. ...
Major endocrine glands. ...
An endocrine gland is one of a set of internal organs involved in the secretion of hormones into the blood. ...
The hypothalamus links the nervous system to the endocrine system via the pituitary gland (hypophysis). ...
| Latin = hypophysis, glandula pituitaria | GraySubject = 275 | GrayPage = 1275 | Image = Gray1180. ...
It has been suggested that HTPA be merged into this article or section. ...
In mammals, the adrenal glands (also known as suprarenal glands) are the triangle-shaped endocrine glands that sit on top of the kidneys; their name indicates that position (ad-, near or at + -renes, kidneys). They are chiefly responsible for regulating the stress response through the synthesis of corticosteroids and catecholamines...
The hypothalamic-pituitary-thyroid axis (HPT axis for short) is part of the endocrine system responsible in part for the regulation of metabolism. ...
For other uses, see Thyroid cartilage. ...
Parafollicular cells also called C cells, are cells in the thyroid which produce and secrete calcitonin. ...
Thyroid epithelial cells are cells in the thyroid gland which produce and secrete thyroxine and triiodothyronine. ...
The four human parathyroid glands are adjacent to the thyroid. ...
Parathyroid chief cells are cells in the parathyroid glands which produce parathyroid hormone. ...
Gonadal axis: Testes - Ovaries - Corpus luteum | | Other | Pineal gland • Islets of pancreas | [[zh:胎 The hypothalamic-pituitary-gonadal axis (also HPTA) is a way of referring to the combined effects of the hypothalamus, pituitary gland, and gonads as if these individual endocrine glands were a single entity. ...
Look up testes in Wiktionary, the free dictionary. ...
// For ovary as part of plants see ovary (plants) An ovary is an egg-producing reproductive organ found in female organisms. ...
The corpus luteum (Latin for yellow body) is a small, temporary endocrine structure in animals. ...
The pineal gland (also called the pineal body or epiphysis) is a small endocrine gland in the brain. ...
A porcine islet of Langerhans. ...
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