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Bone Age
Bone age is the degree of a person's skeletal development. In children, bone age serves as a measure of physiological maturity and aids in the diagnosis of growth abnormalities, endocrine disorders, and other medical conditions. As a person grows from fetal life through childhood, puberty, and finishes growth as a young adult, the bones of the skeleton change in size and shape. These changes can be seen by x-ray and other imaging techniques. A comparison between the appearance of a patient's bones to a standard set of bone images known to be representative of the average bone shape and size for a given age can be used to assign a "bone age" to the patient. Bone age is distinct from an individual's biological or chronological age, which is the amount of time that has elapsed since birth. Discrepancies between bone age and biological age can be seen in people with stunted growth, where bone age may be less than biological age. Similarly, a bone age that is older than a person's chron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Of Hand, Where Bone Age Is Automatically Found By BoneXpert Software
An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ranging from 10 Nanometre, nanometers to 10 Picometre, picometers, corresponding to frequency, frequencies in the range of 30 Hertz, petahertz to 30 Hertz, exahertz ( to ) and photon energies in the range of 100 electronvolt, eV to 100 keV, respectively. X-rays were discovered in 1895 in science, 1895 by the German scientist Wilhelm Röntgen, Wilhelm Conrad Röntgen, who named it ''X-radiation'' to signify an unknown type of radiation.Novelline, Robert (1997). ''Squire's Fundamentals of Radiology''. Harvard University Press. 5th edition. . X-rays can penetrate many solid substances such as construction materials and living tissue, so X-ray radiography is widely used in medical diagnostics (e.g., checking for Bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ossification Center
An ossification center is a point where ossification of the hyaline cartilage begins. The first step in ossification is that the chondrocytes at this point become hypertrophic and arrange themselves in rows. The matrix in which they are imbedded increases in quantity, so that the cells become further separated from each other. A deposit of calcareous material now takes place in this matrix, between the rows of cells, so that they become separated from each other by longitudinal columns of calcified matrix, presenting a granular and opaque appearance. Here and there the matrix between two cells of the same row also becomes calcified, and transverse bars of calcified substance stretch across from one calcareous column to another. Thus, there are longitudinal groups of the cartilage cells enclosed in oblong cavities, the walls of which are formed of calcified matrix which cuts off all nutrition from the cells; the cells, in consequence, atrophy, leaving spaces called the primary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adrenarche
Adrenarche is an early stage in sexual maturation that happens in some higher primates (including humans), typically peaks at around 20 years of age, and is involved in the development of pubic hair, body odor, skin oiliness#Oily skin, skin oiliness, axillary hair, sexual attraction/sexual desire/increased libido and mild acne. During adrenarche the adrenal glands secrete increased levels of weak adrenal androgens, including dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), and androstenedione (A4), but without increased cortisol levels. Adrenarche is the result of the development of a new zone of the adrenal cortex, the zona reticularis. Adrenarche is a process related to puberty, but distinct from hypothalamic–pituitary–gonadal axis (HPG axis) maturation and function. Occurrence Adrenarche occurs starting at the age of 6 years. After the first year of life, the adrenal glands secrete very low levels of adrenal androgens. Adrenarche begins on avera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Congenital Adrenal Hyperplasia
Congenital adrenal hyperplasia (CAH) is a group of Genetic disorder#Autosomal recessive, autosomal recessive disorders characterized by impaired cortisol synthesis. It results from the deficiency of one of the five enzymes required for the Biosynthesis, synthesis of cortisol in the adrenal cortex. Most of these disorders involve excessive or deficient production of hormones such as glucocorticoids, mineralocorticoids, or sex steroids, and can alter development of primary sex characteristic, primary or secondary sex characteristics in some affected infants, children, or adults. It is one of the most common autosomal recessive disorders in humans. Types CAH can occur in various forms. The clinical presentation of each form is different and depends to a large extent on the underlying enzyme defect, its precursor retention, and deficient products. Classical forms appear in infancy and nonclassical forms appear in late childhood. The presentation in patients with classic CAH can be fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Steroid
Sex hormones, also known as sex steroids, gonadocorticoids and gonadal steroids, are steroid hormones that interact with vertebrate steroid hormone receptors. The sex hormones include the androgens, estrogens, and progestogens. Their effects are mediated by slow genomic mechanisms through nuclear receptors as well as by fast nongenomic mechanisms through membrane-associated receptors and signaling cascades. Certain polypeptide hormones including the luteinizing hormone, follicle-stimulating hormone, and gonadotropin-releasing hormone – each associated with the gonadotropin axis – are usually not regarded as sex hormones, although they play major sex-related roles. Production Natural sex hormones are made by the gonads (ovaries or testicles), by adrenal glands, or by conversion from other sex steroids in other tissue such as liver or fat. Image:Steroidogenesis.svg Image:Biosinthesis of steroid hormones (simplified version).jpg Image:Biosinthesis of steroid hormones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delayed Puberty
Delayed puberty is when a person lacks or has incomplete development of specific sexual characteristics past the usual age of onset of puberty. The person may have no physical or hormone, hormonal signs that puberty has begun. In the United States, girls are considered to have delayed puberty if they lack breast development by age 13 or have not started menstruating by age 15. Boys are considered to have delayed puberty if they lack enlargement of the testicles by age 14. Delayed puberty affects about 2% of adolescents. Most commonly, puberty may be delayed for several years and still occur normally, in which case it is considered constitutional delay of growth and puberty, a common variation of healthy physical development. Delay of puberty may also occur due to various causes such as malnutrition, various systemic diseases, or defects of the reproductive system (hypogonadism) or the body's responsiveness to sex hormones. Initial workup for delayed puberty not due to a chronic co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Springer Publishing
Springer Publishing Company is an American publishing company of academic journals and books, focusing on the fields of nursing, gerontology, psychology, social work, counseling, public health, and rehabilitation (neuropsychology). It was established in 1951 by Bernhard Springer, a great-grandson of Julius Springer, and is based in Midtown Manhattan, New York City. History Springer Publishing Company was founded in 1950 by Bernhard Springer, the Berlin-born great-grandson of Julius Springer, who founded Springer Science+Business Media, Springer-Verlag (now Springer Science+Business Media). Springer Publishing's first landmark publications included ''Livestock Health Encyclopedia'' by R. Seiden and the 1952 ''Handbook of Cardiology for Nurses''. The company's books soon branched into other fields, including medicine and psychology. Nursing publications grew rapidly in number, as Modell's ''Drugs in Current Use'', a small annual paperback, sold over 150,000 copies over several edi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Deviation
In statistics, the standard deviation is a measure of the amount of variation of the values of a variable about its Expected value, mean. A low standard Deviation (statistics), deviation indicates that the values tend to be close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the values are spread out over a wider range. The standard deviation is commonly used in the determination of what constitutes an outlier and what does not. Standard deviation may be abbreviated SD or std dev, and is most commonly represented in mathematical texts and equations by the lowercase Greek alphabet, Greek letter Sigma, σ (sigma), for the population standard deviation, or the Latin script, Latin letter ''s'', for the sample standard deviation. The standard deviation of a random variable, Sample (statistics), sample, statistical population, data set, or probability distribution is the square root of its variance. (For a finite population, v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cervical Vertebral Maturation Method
Cervical vertebral maturation method is an assessment of skeletal age based on the cervical vertebrae, as seen in a cephalometric radiograph. also called as CVM. It was developed by Lamparski in 1972. Cephalometric radiographs are usually obtained for orthodontic patients, which offer the benefit of avoiding additional radiation exposure when gauging the adolescent growth spurt. Nevertheless, several studies have contested the reliability and accuracy of deriving skeletal age from cervical vertebrae, with one study contending that chronologic age is just as reliable as CVM method. Research into CVM has yielded notable findings in regards to intraobserver and interobserver reliability. Comparable results to that of hand–wrist radiographs have been recorded, which was further affirmed by the outcome of one specific prospective review of the literature. History Estimating the bone age of a living child is typically performed by comparing images of their bones to images of models of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Mourilyan Tanner
James Mourilyan Tanner (1 August 1920 – 11 August 2010) was a British paediatric endocrinologist who was best known for his development of the Tanner scale, which measures the stages of sexual development during puberty. He was a professor emeritus of the Institute of Child Health at the University of London. Biography Tanner was born on 1 August 1920 in Camberley, Surrey, United Kingdom and was educated at Marlborough College and University College of the South West of England. His family travelled widely while he was a youth because his father, a soldier in the British Army, was stationed in various locations. Tanner was a top-ranked hurdler who might well have participated in the 1940 Summer Olympics which were to be held in London, but were cancelled after the outbreak of World War II. He decided to become a doctor and not follow his father into the military after his brother was killed early in the war. He attended St Mary's Hospital, London, under a scholarship in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bones Of The Hand And Wrist Used For Bone Age Estimation In The Tanner-Whitehouse Method
A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, and enable mobility. Bones come in a variety of shapes and sizes and have complex internal and external structures. They are lightweight yet strong and hard and serve multiple functions. Bone tissue (osseous tissue), which is also called bone in the uncountable sense of that word, is hard tissue, a type of specialised connective tissue. It has a honeycomb-like matrix internally, which helps to give the bone rigidity. Bone tissue is made up of different types of bone cells. Osteoblasts and osteocytes are involved in the formation and mineralisation of bone; osteoclasts are involved in the resorption of bone tissue. Modified (flattened) osteoblasts become the lining cells that form a protective layer on the bone surface. The mineralised matrix ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wrist
In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; "The wrist contains eight bones, roughly aligned in two rows, known as the carpal bones." (2) the wrist joint or radiocarpal joint, the joint between the radius and the carpus and; (3) the anatomical region surrounding the carpus including the distal parts of the bones of the forearm and the proximal parts of the metacarpus or five metacarpal bones and the series of joints between these bones, thus referred to as ''wrist joints''. "With the large number of bones composing the wrist (ulna, radius, eight carpas, and five metacarpals), it makes sense that there are many, many joints that make up the structure known as the wrist." This region also includes the carpal tunnel, the anatomical snuff box, bracelet lines, the flexor retinaculum, and the extensor retinaculum. As a consequence of these various definitions, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
