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Caudal Cell Mass
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 neurocoele 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 neurocoele from the initial neurulation. The caudal cell mass will ultimately differentiate and form into many sacra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human
Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing#Evolution of hairlessness, hairlessness, bipedality, bipedalism, and high Human intelligence, intelligence. Humans have large Human brain, brains, enabling more advanced cognitive skills that facilitate successful adaptation to varied environments, development of sophisticated tools, and formation of complex social structures and civilizations. Humans are Sociality, highly social, with individual humans tending to belong to a Level of analysis, multi-layered network of distinct social groups — from families and peer groups to corporations and State (polity), political states. As such, social interactions between humans have established a wide variety of Value theory, values, norm (sociology), social norms, languages, and traditions (co ... [...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 congenital disorder in which the fetal development of the lower Vertebral column, spine—the Caudal (anatomical term), 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. ... [...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 mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gestational Diabetes
Gestational diabetes is a condition in which a woman without diabetes develops hyperglycemia, high blood sugar levels during pregnancy. Gestational diabetes generally results in few symptoms. Obesity increases the rate of pre-eclampsia, cesarean sections, and embryo macrosomia, as well as gestational diabetes. Babies born to individuals 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 (medicine), screening is recommended betw ... [...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. In general, the more severe cases of limb fusion correlate with more severe dysplas ... [...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, is a failure of the normal development of the tissues of the anterior segment of the eye. It leads to anomalies in the structu ... [...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, ... [...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 Vertebral column, 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 Human vertebral column, 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 #Prevention, folate fortification of grain products was started. The num ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three Evolution of mammalian auditory ossicles, middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors Genetic divergence, diverged in the Carboniferous Period over 300 million years ago. Around 6,640 Neontology#Extant taxon, extant species of mammals have been described and divided into 27 Order (biology), orders. The study of mammals is called mammalogy. The largest orders of mammals, by number of species, are the rodents, bats, and eulipotyphlans (including hedgehogs, Mole (animal), moles and shrews). The next three are the primates (including humans, monkeys and lemurs), the Artiodactyl, even-toed ungulates (including pigs, camels, and whales), and the Carnivora (including Felidae, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conus Medullaris
The conus medullaris (Latin for "medullary cone") or conus terminalis is the tapered, lower end of the spinal cord. It occurs near lumbar vertebral levels 1 (L1) and 2 (L2), occasionally lower. The upper end of the conus medullaris is usually not well defined, however, its corresponding spinal cord segments are usually S1–S5. After the spinal cord tapers out, the spinal nerves continue to branch out diagonally, forming the cauda equina. The pia mater that surrounds the spinal cord, however, projects directly downward, forming a slender filament called the filum terminale, which connects the conus medullaris to the back of the coccyx. The filum terminale provides a connection between the conus medullaris and the coccyx which stabilizes the entire spinal cord. Blood supply The blood supply consists of three spinal arterial vessels—the anterior median longitudinal arterial trunk and the right and left posterior spinal arteries. Other less prominent sources of blood supply in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumen (anatomy)
In biology, a lumen (: 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 *the fluid-filled cavity forming in the blastocyst during pre-implantation development called the blastocoel In cell biology, lumen is a membrane-defined space that is found inside several organelles, cellular components, or structures, including thylakoid, endoplasmic reticulum, Golgi apparatus, lysosome, mitochondrion, and microtubule. Transluminal procedures ''Transluminal procedures'' are procedures occur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
