|
Brushfield Spots
Brushfield spots are small, white or greyish/brown spots on the periphery of the iris in the human eye due to aggregation of connective tissue, a normal constituent of the iris stroma. The spots are named after the physician Thomas Brushfield, who first described them in his 1924 M.D. thesis. Brushfield spots are a characteristic feature of the chromosomal disorder Down syndrome or trisomy 21. They occur in 35–78% of newborn infants with Down syndrome. Brushfield spots tend to be obscured by pigmentation of the anterior border layer of the iris in patients with darker irides. Hence, they are much more likely to be observed in children with lightly pigmented eyes. Brushfield spots are more commonly found in Down syndrome patients of European descent than similarly affected children of Asian heritage. Brushfield spots comprise focal areas of iris stromal hyperplasia, surrounded by relative hypoplasia Hypoplasia (from Ancient Greek ὑπo- ''hypo-'' 'under' + πλάσις '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brushfield Eyes Magnified
Brushfield is a hamlet and civil parish in the Derbyshire Dales district of Derbyshire, England, in the Peak District National Park. It is about 8 miles east of Buxton. According to the 2001 census it had a population of 13. In 2007 it had just three houses. Several holiday lets are run by two separate families. One of these cottages is called the 'Old School House', a small one-bed house of stone. There are three scheduled monuments in the parish: bowl barrow A bowl barrow is a type of burial mound or tumulus. A barrow is a mound of earth used to cover a tomb. The bowl barrow gets its name from its resemblance to an upturned bowl. Related terms include ''cairn circle'', ''cairn ring'', ''howe'', ''ke ...s at Brushfield Hough and Putwell Hill and High Field '' hlæw'', a rare pre-Christian burial monument dating from around 600AD. References Towns and villages of the Peak District Civil parishes in Derbyshire Hamlets in Derbyshire Derbyshire Dales {{Derbyshire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iris (anatomy)
In humans and most mammals and birds, the iris (plural: ''irides'' or ''irises'') is a thin, annular structure in the eye, responsible for controlling the diameter and size of the pupil, and thus the amount of light reaching the retina. Eye color is defined by the iris. In optical terms, the pupil is the eye's aperture, while the iris is the diaphragm. Structure The iris consists of two layers: the front pigmented fibrovascular layer known as a stroma and, beneath the stroma, pigmented epithelial cells. The stroma is connected to a sphincter muscle (sphincter pupillae), which contracts the pupil in a circular motion, and a set of dilator muscles ( dilator pupillae), which pull the iris radially to enlarge the pupil, pulling it in folds. The sphincter pupillae is the opposing muscle of the dilator pupillae. The pupil's diameter, and thus the inner border of the iris, changes size when constricting or dilating. The outer border of the iris does not change size. The constricti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Eye
The human eye is a sensory organ, part of the sensory nervous system, that reacts to visible light and allows humans to use visual information for various purposes including seeing things, keeping balance, and maintaining circadian rhythm. The eye can be considered as a living optical device. It is approximately spherical in shape, with its outer layers, such as the outermost, white part of the eye (the sclera) and one of its inner layers (the pigmented choroid) keeping the eye essentially light tight except on the eye's optic axis. In order, along the optic axis, the optical components consist of a first lens (the cornea—the clear part of the eye) that accomplishes most of the focussing of light from the outside world; then an aperture (the pupil) in a diaphragm (the iris—the coloured part of the eye) that controls the amount of light entering the interior of the eye; then another lens (the crystalline lens) that accomplishes the remaining focussing of light into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Connective Tissue
Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. The three meninges, membranes that envelop the brain and spinal cord are composed of connective tissue. Most types of connective tissue consists of three main components: elastic and collagen fibers, ground substance, and cells. Blood, and lymph are classed as specialized fluid connective tissues that do not contain fiber. All are immersed in the body water. The cells of connective tissue include fibroblasts, adipocytes, macrophages, mast cells and leucocytes. The term "connective tissue" (in German, ''Bindegewebe'') was introduced in 1830 by Johannes Peter Müller. The tissue was already recognized as a distinct class in the 18th century. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Brushfield
Thomas Brushfield (1858–1937) was an English psychiatrist who worked in the field of intellectual disability. He is remembered for describing Brushfield spots, and was the medical superintendent of the Fountain Hospital for Imbeciles, Tooting, from 1914 to 1927. He died on 17 May 1937, aged 79. He was the son of Thomas Nadauld Brushfield (1828–1910), a noted authority in the same field and expert on the life of Sir Walter Raleigh Sir Walter Raleigh (; – 29 October 1618) was an English statesman, soldier, writer and explorer. One of the most notable figures of the Elizabethan era, he played a leading part in English colonisation of North America, suppressed rebellion .... References English psychiatrists 1858 births 1937 deaths Eye color {{UK-psychiatrist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doctor Of Medicine
Doctor of Medicine (abbreviated M.D., from the Latin language, Latin ''Medicinae Doctor'') is a medical degree, the meaning of which varies between different jurisdictions. In the United States, and some other countries, the M.D. denotes a professional degree. This generally arose because many in 18th-century medical professions trained in Scotland, which used the M.D. degree nomenclature. In England, however, Bachelor of Medicine, Bachelor of Surgery was used and eventually in the 19th century became the standard in Scotland too. Thus, in the United Kingdom, Republic of Ireland, Ireland and other countries, the M.D. is a research doctorate, honorary degree, honorary doctorate or applied clinical degree restricted to those who already hold a professional degree (Bachelor's/Master's/Doctoral) in medicine. In those countries, the equivalent professional degree to the North American, and some others use of M.D., is still typically titled Bachelor of Medicine, Bachelor of Surgery (M.B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Down Syndrome
Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with physical growth delays, mild to moderate intellectual disability, and characteristic facial features. The average IQ of a young adult with Down syndrome is 50, equivalent to the mental ability of an eight- or nine-year-old child, but this can vary widely. The parents of the affected individual are usually genetically normal. The probability increases from less than 0.1% in 20-year-old mothers to 3% in those of age 45. The extra chromosome is believed to occur by chance, with no known behavioral activity or environmental factor that changes the probability. Down syndrome can be identified during pregnancy by prenatal screening followed by diagnostic testing or after birth by direct observation and genetic testing. Since the introduction of screening, Down syndrome pregnancies are often abor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia and it is located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. Comprising the westernmost peninsulas of Eurasia, it shares the continental landmass of Afro-Eurasia with both Africa and Asia. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south and Asia to the east. Europe is commonly considered to be Boundaries between the continents of Earth#Asia and Europe, separated from Asia by the drainage divide, watershed of the Ural Mountains, the Ural (river), Ural River, the Caspian Sea, the Greater Caucasus, the Black Sea and the waterways of the Turkish Straits. "Europe" (pp. 68–69); "Asia" (pp. 90–91): "A commonly accepted division between Asia and E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area of , about 30% of Earth's total land area and 8.7% of Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Its 4.7 billion people constitute roughly 60% of the world's population. In general terms, Asia is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, and on the north by the Arctic Ocean. The border of Asia with Europe is a historical and cultural construct, as there is no clear physical and geographical separation between them. It is somewhat arbitrary and has moved since its first conception in classical antiquity. The division of Eurasia into two continents reflects East–West cultural, linguistic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stroma Of Iris
The stroma of the iris is a fibrovascular layer of tissue. It is the upper layer of two in the iris. Structure The stroma is a delicate interlacement of fibres. Some circle the circumference of the iris and the majority radiate toward the pupil. Blood vessels and nerves intersperse this mesh. In dark eyes, the stroma often contains pigment granules. Blue eyes and the eyes of albinos, however, lack pigment. The stroma connects to a sphincter muscle (sphincter pupillae), which contracts the pupil in a circular motion, and a set of dilator muscles (dilator pupillae) which pull the iris radially to enlarge the pupil, pulling it in folds. The back surface is covered by a commonly, heavily pigmented epithelial Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ... layer that is two cells ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperplasia
Hyperplasia (from ancient Greek ὑπέρ ''huper'' 'over' + πλάσις ''plasis'' 'formation'), or hypergenesis, is an enlargement of an organ or tissue caused by an increase in the amount of organic tissue that results from cell proliferation. It may lead to the gross enlargement of an organ, and the term is sometimes confused with benign neoplasia or benign tumor. Hyperplasia is a common preneoplastic response to stimulus. Microscopically, cells resemble normal cells but are increased in numbers. Sometimes cells may also be increased in size (hypertrophy). Hyperplasia is different from hypertrophy in that the adaptive cell change in hypertrophy is an increase in the ''size'' of cells, whereas hyperplasia involves an increase in the ''number'' of cells. Causes Hyperplasia may be due to any number of causes, including proliferation of basal layer of epidermis to compensate skin loss, chronic inflammatory response, hormonal dysfunctions, or compensation for damage o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoplasia
Hypoplasia (from Ancient Greek ὑπo- ''hypo-'' 'under' + πλάσις ''plasis'' 'formation'; adjective form ''hypoplastic'') is underdevelopment or incomplete development of a tissue or organ. Dictionary of Cell and Molecular Biology (11 March 2008) Although the term is not always used precisely, it properly refers to an inadequate or below-normal number of cells.Hypoplasia Stedman's Medical Dictionary. lww.com Hypoplasia is similar to |
.svg "Click for more on -> Europe")
