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Tail Bud
In humans and other mammals, the caudal cell mass (also tail bud or caudal eminence in humans) is the aggregate of undifferentiated cells at the caudal end on the spine. The caudal end of the spinal cord first begins to form after primary neurulation has taken place, indicating that it develops after the cranial portion of the spinal cord has developed. Following neurulation, the caudal tail begins to form a neurocele as it develops a hollow core. After this, secondary neurulation occurs in which the medullary cord begins to form and is filled with many cavities that ultimately form the lumen. The cavities formed from the initial and secondary neurulation combine to form one uninterrupted cavity. There is still speculation on the formation of the caudal cell mass in humans with arguments being made for it arising from many cavities or the continuing growth of the neurocele from the initial neurulation. The caudal cell mass will ultimately differentiate and form into many sacral str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, and language. Humans are highly social and tend to live in complex social structures composed of many cooperating and competing groups, from families and kinship networks to political states. Social interactions between humans have established a wide variety of values, social norms, and rituals, which bolster human society. Its intelligence and its desire to understand and influence the environment and to explain and manipulate phenomena have motivated humanity's development of science, philosophy, mythology, religion, and other fields of study. Although some scientists equate the term ''humans'' with all members of the genus ''Homo'', in common usage, it generally refers to ''Homo sapiens'', the only extant member. Anatomically moder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Regression Syndrome
Caudal regression syndrome, or sacral agenesis (or hypoplasia of the sacrum), is a rare birth defect. It is a congenital disorder in which the fetal development of the lower spine—the caudal partition of the spine—is abnormal. It occurs at a rate of approximately one per 60,000 live births.Medline Plus. Caudal Regression Syndrome.https://medlineplus.gov/genetics/condition/caudal-regression-syndrome/#frequency Some babies are born with very small differences compared to typical development, and others have significant changes. Most grow up to be otherwise typical adults who have difficulty with walking and incontinence. Signs and symptoms This condition exists in a variety of forms, ranging from partial absence of the tail bone regions of the spine to absence of the lower vertebrae, pelvis and parts of the thoracic and/or lumbar areas of the spine. In some cases, where only a small part of the spine is absent, there may be no outward sign of the condition. In cases where more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphogenesis
Morphogenesis (from the Greek ''morphê'' shape and ''genesis'' creation, literally "the generation of form") is the biological process that causes a cell, tissue or organism to develop its shape. It is one of three fundamental aspects of developmental biology along with the control of tissue growth and patterning of cellular differentiation. The process controls the organized spatial distribution of cells during the embryonic development of an organism. Morphogenesis can take place also in a mature organism, such as in the normal maintenance of tissue by stem cells or in regeneration of tissues after damage. Cancer is an example of highly abnormal and pathological tissue morphogenesis. Morphogenesis also describes the development of unicellular life forms that do not have an embryonic stage in their life cycle. Morphogenesis is essential for the evolution of new forms. Morphogenesis is a mechanical process involving forces that generate mechanical stress, strain, and moveme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gestational Diabetes
Gestational diabetes is a condition in which a woman without diabetes develops high blood sugar levels during pregnancy. Gestational diabetes generally results in few symptoms; however, it increases the risk of pre-eclampsia, depression, and of needing a Caesarean section. Babies born to mothers with poorly treated gestational diabetes are at increased risk of macrosomia, of having hypoglycemia after birth, and of jaundice. If untreated, diabetes can also result in stillbirth. Long term, children are at higher risk of being overweight and of developing type 2 diabetes. Gestational diabetes can occur during pregnancy because of insulin resistance or reduced production of insulin. Risk factors include being overweight, previously having gestational diabetes, a family history of type 2 diabetes, and having polycystic ovarian syndrome. Diagnosis is by blood tests. For those at normal risk, screening is recommended between 24 and 28 weeks' gestation. For those at high risk, testin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sirenomelia
Sirenomelia, also called mermaid syndrome, is a rare congenital deformity in which the legs are fused together, giving the appearance of a mermaid's tail, hence the nickname. Classification Sirenomelia is classified by the skeletal structure of the lower limb, ranging from class I, where all bones are present and only the soft tissues are fused, to class VII where the only bone present is a fused femur. It has also been classified as an expanded part of the VACTERL association and as a form of caudal regression syndrome. Presentation Sirenomelia is mainly characterized by the fusion of both legs with rotation of the fibula. It may include the absence of the lower spine, as well as abnormalities of the pelvis and renal organs. It was previously thought to be a severe form of sacral agensis/caudal regression syndrome, but more recent research confirms that these two conditions are not related. NORD has a separate report on caudal regression syndrome. In general, the more seve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Currarino Syndrome
Currarino syndrome is an inherited congenital disorder where either the sacrum (the fused vertebrae forming the back of the pelvis) is not formed properly, or there is a mass in the presacral space in front of the sacrum, and there are malformations of the anus or rectum. It occurs in approximately 1 in 100,000 people. Anterior sacral meningocele is the most common presacral mass in patients with Currarino syndrome, occurring in 60% of cases. Its presence may significantly affect the surgical management of these patients. Other potential presacral masses include presacral teratoma and enteric cyst. Presacral teratoma usually is considered to be a variant of sacrococcygeal teratoma. However, the presacral teratoma that is characteristic of the Currarino syndrome may be a distinct kind. Genetics The disorder is an autosomal dominant genetic trait caused by a mutation in the HLXB9 homeobox gene. In 2000 the first large series of Currarino cases was genetically screened for HLXB9 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysgenesis (embryology)
Dysgenesis is an abnormal organ development during embryonic growth and development. As opposed to agenesis, which refers to the complete failure of an organ to develop, dysgenesis usually implies disordered development or malformation and in some cases represents the milder end of a spectrum of abnormalities. Dysgenesis occurs during fetal development immediately after conception. Classification One of the first organs that is affected is the brain, this is known as cerebral dysgenesis. Dysplasia is a form of dysgenesis in adults that alters the size and shape of their cells that lead to abnormal development. One of the most common forms of dysgenesis is within the gonads. Examples: * Gonadal dysgenesis * Adrenal dysgenesis * Thyroid dysgenesis * Anterior segment dysgenesis Anterior segment mesenchymal dysgenesis, or simply anterior segment dysgenesis (ASD), is a failure of the normal development of the tissues of the anterior segment of the eye. It leads to anomalies in the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agenesis
In medicine, agenesis () refers to the failure of an organ to develop during embryonic growth and development due to the absence of primordial tissue. Many forms of agenesis are referred to by individual names, depending on the organ affected: * Agenesis of the corpus callosum - failure of the Corpus callosum to develop *Renal agenesis - failure of one or both of the kidneys to develop * Amelia - failure of the arms or legs to develop *Penile agenesis - failure of penis to develop *Müllerian agenesis - failure of the uterus and part of the vagina to develop *Agenesis of the gallbladder - failure of the Gallbladder to develop. A person may not realize they have this condition unless they undergo surgery or medical imaging, since the gallbladder is neither externally visible nor essential. __TOC__ Eye agenesis Eye agenesis is a medical condition in which people are born with no eyes. Dental & oral agenesis *Anodontia, absence of all primary or permanent teeth. *Aglossia, absence o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Dysraphism
Neural tube defects (NTDs) are a group of birth defects in which an opening in the spine or cranium remains from early in human development. In the third week of pregnancy called gastrulation, specialized cells on the dorsal side of the embryo begin to change shape and form the neural tube. When the neural tube does not close completely, an NTD develops. Specific types include: spina bifida which affects the spine, anencephaly which results in little to no brain, encephalocele which affects the skull, and iniencephaly which results in severe neck problems. NTDs are one of the most common birth defects, affecting over 300,000 births each year worldwide. For example, spina bifida affects approximately 1,500 births annually in the United States, or about 3.5 in every 10,000 (0.035% of US births), which has decreased from around 5 per 10,000 (0.05% of US births) since folate fortification of grain products was started. The number of deaths in the US each year due to neural tube d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together with Saur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conus Medullaris
''Conus'' is a genus of predatory sea snails, or cone snails, marine gastropod mollusks in the family Conidae.Bouchet, P.; Gofas, S. (2015). Conus Linnaeus, 1758. In: MolluscaBase (2015). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=137813 on 2015-11-12 Prior to 2009, cone snail species had all traditionally been grouped into the single genus ''Conus''. However, ''Conus'' is now more precisely defined, and there are several other accepted genera of cone snails. For a list of the currently accepted genera, see Conidae. Description The thick shell of species in the genus ''Conus'' sensu stricto, is obconic, with the whorls enrolled upon themselves. The spire is short, smooth or tuberculated. The narrow aperture is elongated with parallel margins and is truncated at the base. The operculum is very small relative to the size of the shell. It is corneous, narrowly elongated, with an apical nucleus, and the impression ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumen (anatomy)
In biology, a lumen (plural lumina) is the inside space of a tubular structure, such as an artery or intestine. It comes . It can refer to: *The interior of a vessel, such as the central space in an artery, vein or capillary through which blood flows. *The interior of the gastrointestinal tract *The pathways of the bronchi in the lungs *The interior of renal tubules and urinary collecting ducts *The pathways of the female genital tract, starting with a single pathway of the vagina, splitting up in two lumina in the uterus, both of which continue through the Fallopian tubes In cell biology, a lumen is a membrane-defined space that is found inside several organelles, cellular components, or structures: *thylakoid, endoplasmic reticulum, Golgi apparatus, lysosome, mitochondrion, or microtubule Transluminal procedures ''Transluminal procedures'' are procedures occurring through lumina, including: *Natural orifice transluminal endoscopic surgery in the lumina of, for example, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
