1.
Anatomical terminology
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Anatomical terminology is a form of scientific terminology used by anatomists, zoologists, and health professionals such as doctors. Anatomical terminology uses many terms, suffixes, and prefixes deriving from Ancient Greek. These terms can be confusing to those unfamiliar with them, but can be more precise reducing ambiguity, also, since these anatomical terms are not used in everyday conversation, their meanings are less likely to change, and less likely to be misinterpreted. By using precise anatomical terminology such ambiguity is eliminated, an international standard for anatomical terminology, Terminologia Anatomica has been created. Anatomical terminology has quite regular morphology, the prefixes and suffixes are used to add meanings to different roots. The root of a term refers to an organ, tissue. For example, in the disorder hypertension, the prefix hyper- means high or over, the roots, prefixes and suffixes are often derived from Greek or Latin, and often quite dissimilar from their English-language variants. Latin names of such as musculus biceps brachii can be split up and refer to, musculus for muscle, biceps for two-headed. The first word tells us what we are speaking about, the second describes it, when describing the position of anatomical structures, structures may be described according to the anatomical landmark they are near. These landmarks may include structures, such as the umbilicus or sternum, or anatomical lines, the cephalon or cephalic region refers to the head. This area is differentiated into the cranium, facies, frons, oculus, auris, bucca, nausus, oris. The neck area is called the cervicis or cervical region, examples of structures named according to this include the frontalis muscle, submental lymph nodes, buccal membrane and orbicularis oculi muscle. Sometimes, unique terminology is used to reduce confusion in different parts of the body, for example, different terms are used when it comes to the skull in compliance with its embryonic origin and its tilted position compared to in other animals. Here, Rostral refers to proximity to the front of the nose, similarly, in the arms, different terminology is often used in the arms, in part to reduce ambiguity as what is the front, back, inner and outer surfaces. For this reason, the terms below are used, Radial referring to the radius bone, ulnar referring to the ulna bone, medially positioned when in the standard anatomical position. Other terms are used to describe the movement and actions of the hands and feet. International morphological terminology is used by the colleges of medicine and dentistry and it facilitates communication and exchanges between scientists from different countries of the world and it is used daily in the fields of research, teaching and medical care. The international morphological terminology refers to morphological sciences as a biological sciences branch, in this field, the form and structure are examined as well as the changes or developments in the organism
2.
Epithelium
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Epithelial is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the cavities and surfaces of blood vessels and organs throughout the body, there are three principal shapes of epithelial cell, squamous, columnar, and cuboidal. All glands are made up of epithelial cells, functions of epithelial cells include secretion, selective absorption, protection, transcellular transport, and sensing. Epithelial layers contain no blood vessels, so they must receive nourishment via diffusion of substances from the connective tissue. Cell junctions are well-employed in epithelial tissues, in general, epithelial tissues are classified by the number of their layers and by the shape and function of the cells. The three principal shapes associated with epithelial cells are—squamous, cuboidal and columnar, squamous epithelium has cells that are wider than their height. Cuboidal epithelium has cells whose height and width are approximately the same, columnar epithelium has cells taller than they are wide. However, when taller simple columnar epithelial cells are viewed in cross section showing several nuclei appearing at different heights and this kind of epithelium is therefore described as pseudostratified columnar epithelium. Transitional epithelium has cells that can change from squamous to cuboidal, Simple epithelium is a single layer of cells with every cell in direct contact with the basement membrane that separates it from the underlying connective tissue. In general, it is found where absorption and filtration occur, the thinness of the epithelial barrier facilitates these processes. In general, simple epithelial tissues are classified by the shape of their cells, the four major classes of simple epithelium are, simple squamous, simple cuboidal, simple columnar, pseudostratified. Simple squamous, which is found lining areas where passive diffusion of gases occur, E. g. skin, walls of capillaries, linings of the pericardial, pleural, and peritoneal cavities, as well as the linings of the alveoli of the lungs. Simple cuboidal, these cells may have secretory, absorptive, or excretory functions, examples include small collecting ducts of kidney, pancreas and salivary gland. Simple columnar, cells can be secretory, absorptive, or excretory, Simple columnar epithelium can be ciliated or non-ciliated, ciliated columnar is found in the reproductive tract. Non-ciliated epithelium can also possess microvilli, pseudostratified columnar epithelium, can be ciliated or non-ciliated. The ciliated type is called respiratory epithelium as it is almost exclusively confined to the larger respiratory airways of the nasal cavity, trachea. Stratified epithelium differs from simple epithelium in that it is multilayered and it is therefore found where body linings have to withstand mechanical or chemical insult such that layers can be abraded and lost without exposing subepithelial layers. Cells flatten as the layers become more apical, though in their most basal layers the cells can be squamous, stratified epithelia can have the following specializations, The basic cell types are squamous, cuboidal, and columnar classed by their shape
3.
Mammal
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Mammals are any vertebrates within the class Mammalia, a clade of endothermic amniotes distinguished from reptiles by the possession of a neocortex, hair, three middle ear bones and mammary glands. All female mammals nurse their young with milk, secreted from the mammary glands, Mammals include the largest animals on the planet, the great whales. The basic body type is a quadruped, but some mammals are adapted for life at sea, in the air, in trees. The largest group of mammals, the placentals, have a placenta, Mammals range in size from the 30–40 mm bumblebee bat to the 30-meter blue whale. With the exception of the five species of monotreme, all modern mammals give birth to live young, most mammals, including the six most species-rich orders, belong to the placental group. The largest orders are the rodents, bats and Soricomorpha, the next three biggest orders, depending on the biological classification scheme used, are the Primates, the Cetartiodactyla, and the Carnivora. Living mammals are divided into the Yinotheria and Theriiformes There are around 5450 species of mammal, in some classifications, extant mammals are divided into two subclasses, the Prototheria, that is, the order Monotremata, and the Theria, or the infraclasses Metatheria and Eutheria. The marsupials constitute the group of the Metatheria, and include all living metatherians as well as many extinct ones. Much of the changes reflect the advances of cladistic analysis and molecular genetics, findings from molecular genetics, for example, have prompted adopting new groups, such as the Afrotheria, and abandoning traditional groups, such as the Insectivora. The mammals represent the only living Synapsida, which together with the Sauropsida form the Amniota clade, the early synapsid mammalian ancestors were sphenacodont pelycosaurs, a group that produced the non-mammalian Dimetrodon. At the end of the Carboniferous period, this group diverged from the line that led to todays reptiles. Some mammals are intelligent, with some possessing large brains, self-awareness, Mammals can communicate and vocalize in several different ways, including the production of ultrasound, scent-marking, alarm signals, singing, and echolocation. Mammals can organize themselves into fission-fusion societies, harems, and hierarchies, most mammals are polygynous, but some can be monogamous or polyandrous. They provided, and continue to provide, power for transport and agriculture, as well as commodities such as meat, dairy products, wool. Mammals are hunted or raced for sport, and are used as model organisms in science, Mammals have been depicted in art since Palaeolithic times, and appear in literature, film, mythology, and religion. Defaunation of mammals is primarily driven by anthropogenic factors, such as poaching and habitat destruction, Mammal classification has been through several iterations since Carl Linnaeus initially defined the class. No classification system is accepted, McKenna & Bell and Wilson & Reader provide useful recent compendiums. Though field work gradually made Simpsons classification outdated, it remains the closest thing to a classification of mammals
4.
Menstruation
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Menstruation, also known as a period or monthly, is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. The first period usually begins between twelve and fifteen years of age, a point in time known as menarche, however, periods may occasionally start as young as eight years old and still be considered normal. The average age of the first period is later in the developing world. The typical length of time between the first day of one period and the first day of the next is 21 to 45 days in young women, bleeding usually lasts around 2 to 7 days. Menstruation stops occurring after menopause, which occurs between 45 and 55 years of age. Periods also stop during pregnancy and typically do not resume during the months of breastfeeding. Up to 80% of women report having some symptoms prior to menstruation, common signs and symptoms include acne, tender breasts, bloating, feeling tired, irritability, and mood changes. These may interfere with life, therefore qualifying as premenstrual syndrome. In 3 to 8%, symptoms are severe, a lack of periods, known as amenorrhea, is when periods do not occur by age 15 or have not occurred in 90 days. Other problems with the cycle include painful periods and abnormal bleeding such as bleeding between periods or heavy bleeding. Menstruation in other animals occurs in primates, such as apes and monkeys, as well as bats, the menstrual cycle occurs due to the rise and fall of hormones. This cycle results in the thickening of the lining of the uterus, the egg is released from an ovary around day fourteen in the cycle, the thickened lining of the uterus provides nutrients to an embryo after implantation. If pregnancy does not occur, the lining is released in what is known as menstruation, the first menstrual period occurs after the onset of pubertal growth, and is called menarche. The average age of menarche is 12 to 15, however, it may start as early as eight. The average age of the first period is later in the developing world. The average age of menarche has changed little in the United States since the 1950s, Menstruation is the most visible phase of the menstrual cycle and its beginning is used as the marker between cycles. The first day of bleeding is the date used for the last menstrual period. The typical length of time between the first day of one period and the first day of the next is 21 to 45 days in young women, the medical definition of menopause is one year without a period and typically occurs between 45 and 55 in Western countries
5.
Ape
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The simians are the monkeys, cladistically including the apes, the New World monkeys or platyrrhines, and the catarrhine clade consisting of the Old World monkeys and apes. The simian line and the line diverged about 60 million years ago. Forty million years ago, simians from Africa colonized South America, the remaining simians split 25 million years ago into apes and Old World monkeys. Under modern classification, the tarsiers and simians are grouped under the suborder Haplorhini while the strepsirrhines are placed in suborder Strepsirrhini, in anthropoidea, evidences indicate that the Old and the New World primates went through parallel evolution. Primatology, paleoanthropology, and other related fields are split on their usage of the synonymous infraorder names, Simiiformes and Anthropoidea. According to Robert Hoffstetter, the term Simiiformes has priority over Anthropoidea because of the taxonomic term Simii by van der Hoeven, from which it is constructed, dates to 1833. In contrast, Anthropoidea by Mivart dates to 1864, while Simiiformes by Haeckel dates to 1866, Hoffstetter also argued that Simiiformes is also constructed like a proper infraorder name, whereas Anthropoidea ends in -oidea, which is reserved for superfamilies. He also noted that Anthropoidea is too easily confused with anthropoïdes, the simians are split into three distinct groups. The New World monkeys in parvorder Platyrrhini split from the rest of the line about 40 mya. This group split about 25 mya between the Old World monkeys and the apes
6.
Old World monkey
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The Old World monkeys or Cercopithecidae are a family of catarrhines, the only family in the superfamily Cercopithecoidea in the clade of Catarrhini. However, a group of monkeys still survives in Gibraltar to this day. Old World monkeys include many of the most familiar species of primates, such as baboons. Old World monkeys are medium to large in size, and range from arboreal forms, such as the monkeys, to fully terrestrial forms. By superficial appearance, Old World monkeys are unlike apes in that most have tails and, unlike the New World monkeys, technically, the distinction of catarrhines from platyrrhines depends on the structure of the nose, and the distinction of Old World monkeys from apes depends on dentition. In platyrrhines, the nostrils face sideways, while in catarrhines, for example, the colobus monkeys have stubs for thumbs to assist with their arboreal movement, the proboscis monkey has an extraordinary nose, while the snub-nosed monkeys have almost no nose at all. The male mandrills penis is red and the scrotum is lilac, the coloration is more pronounced in dominant males. Most Old World monkeys are at least partially omnivorous, but all prefer plant matter, the Barbary macaques diet consists mostly of leaves and roots, though it will also eat insects and uses cedar trees as a water source. Gestation in the Old World monkeys lasts between five and seven months, births are usually single, although, as with humans, twins occur from time to time. The young are born relatively well-developed, and are able to cling onto their mothers fur with their hands from birth, compared with most other mammals, they take a long time to reach sexual maturity, with four to six years being typical of most species. In most species, daughters remain with their mothers for life, males leave the group on reaching adolescence, and find a new troop to join. In many species, only an adult male lives with each group, driving off all rivals. Group sizes are variable, even within species, depending on the availability of food. Therefore, cladistically, apes, catarrhines and related contemporary extinct groups such as Parapithecidaea are monkeys as well, for any consistent definition of monkey
7.
Bat
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Bats are mammals of the order Chiroptera whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, Bats do not flap their entire forelimbs, as birds do, but instead flap their spread-out digits, which are very long and covered with a thin membrane or patagium. About 70% of bat species are insectivores, most of the rest are frugivores, or fruit eaters. A few species, such as the bat, feed from animals other than insects, with the vampire bats being hematophagous. Bats are present throughout most of the world, with the exception of cold regions. They perform the vital roles of pollinating flowers and dispersing fruit seeds. Bats are economically important, as they consume insect pests, reducing the need for pesticides, the smallest bat is the Kittis hog-nosed bat, measuring 29–34 mm in length,15 cm across the wings and 2–2.6 g in mass. It is also arguably the smallest extant species of mammal, with the Etruscan shrew being the other contender. The largest species of bat are a few species of Pteropus, the Mexican free-tailed bat is the fastest flying animal in horizontal flight. An older English name for bats is flittermouse, which matches their name in other Germanic languages, middle English had bakke, most likely cognate with Old Swedish natbakka, which may have undergone a shift from -k- to -t- influenced by Latin blatta, moth, nocturnal insect. They were formerly grouped in the superorder Archonta, along with the treeshrews, colugos, genetic studies have now placed bats in the superorder Laurasiatheria, along with carnivorans, pangolins, odd-toed ungulates, even-toed ungulates, and cetaceans. A recent study by Zhang et al. places Chiroptera as a taxon to the clade Perissodactyla. The phylogenetic relationships of the different groups of bats have been the subject of much debate and this hypothesis recognized differences between microbats and megabats and acknowledged that flight has only evolved once in mammals. Most molecular biological evidence supports the view that bats form a single or monophyletic group, in the 1980s, a hypothesis based on morphological evidence was offered that stated the Megachiroptera evolved flight separately from the Microchiroptera. The so-called flying primate hypothesis proposes that, when adaptations to flight are removed, one example is that the brains of megabats show a number of advanced characteristics that link them to primates. Although recent genetic studies support the monophyly of bats, debate continues as to the meaning of available genetic. Genetic evidence indicates that megabats originated during the early Eocene and should be placed within the four lines of microbats. Consequently, two new suborders based on molecular data have been proposed and these two new suborders are strongly supported by statistical tests
8.
Placenta
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The placenta provides oxygen and nutrients to growing babies and removes waste products from the babys blood. The placenta attaches to the wall of the uterus, and the umbilical cord develops from the placenta. The umbilical cord is what connects the mother and the baby, Placentas are a defining characteristic of placental mammals, but are also found in some non-mammals with varying levels of development. The homology of structures in various viviparous organisms is debatable. The classical plural is placentae, but the form placentas is common in modern English, prototherial and metatherial mammals produce a choriovitelline placenta that, while connected to the uterine wall, provides nutrients mainly derived from the egg sac. In humans, the placenta averages 22 cm in length and 2–2.5 cm in thickness, with the center being the thickest, and it typically weighs approximately 500 grams. It has a dark reddish-blue or crimson color and it connects to the fetus by an umbilical cord of approximately 55–60 cm in length, which contains two umbilical arteries and one umbilical vein. The umbilical cord inserts into the chorionic plate, vessels branch out over the surface of the placenta and further divide to form a network covered by a thin layer of cells. This results in the formation of villous tree structures, on the maternal side, these villous tree structures are grouped into lobules called cotyledons. In humans, the placenta usually has a shape. The placental flora more closely resembles that of the oral microbiome than either the vaginal or rectal microbiome, in non-human animals, part of the microbiome is passed onto offspring even before the offspring are born. Bacteriologists assume that the same holds true for humans. The placenta begins to develop upon implantation of the blastocyst into the maternal endometrium, the outer layer of the blastocyst becomes the trophoblast, which forms the outer layer of the placenta. This outer layer is divided into two layers, the underlying cytotrophoblast layer and the overlying syncytiotrophoblast layer. The syncytiotrophoblast is a continuous cell layer that covers the surface of the placenta. It forms as a result of differentiation and fusion of the underlying cytotrophoblast cells, the syncytiotrophoblast, thereby contributes to the barrier function of the placenta. Development of the blood supply to the placenta is complete by the end of the first trimester of pregnancy. In preparation for implantation of the blastocyst, the uterine endometrium undergoes decidualisation, spiral arteries in decidua are remodeled so that they become less convoluted and their diameter is increased
9.
Oxygen
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Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the group on the periodic table and is a highly reactive nonmetal. By mass, oxygen is the third-most abundant element in the universe, after hydrogen, at standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O2. This is an important part of the atmosphere and diatomic oxygen gas constitutes 20. 8% of the Earths atmosphere, additionally, as oxides the element makes up almost half of the Earths crust. Most of the mass of living organisms is oxygen as a component of water, conversely, oxygen is continuously replenished by photosynthesis, which uses the energy of sunlight to produce oxygen from water and carbon dioxide. Oxygen is too reactive to remain a free element in air without being continuously replenished by the photosynthetic action of living organisms. Another form of oxygen, ozone, strongly absorbs ultraviolet UVB radiation, but ozone is a pollutant near the surface where it is a by-product of smog. At low earth orbit altitudes, sufficient atomic oxygen is present to cause corrosion of spacecraft, the name oxygen was coined in 1777 by Antoine Lavoisier, whose experiments with oxygen helped to discredit the then-popular phlogiston theory of combustion and corrosion. One of the first known experiments on the relationship between combustion and air was conducted by the 2nd century BCE Greek writer on mechanics, Philo of Byzantium. In his work Pneumatica, Philo observed that inverting a vessel over a burning candle, Philo incorrectly surmised that parts of the air in the vessel were converted into the classical element fire and thus were able to escape through pores in the glass. Many centuries later Leonardo da Vinci built on Philos work by observing that a portion of air is consumed during combustion and respiration, Oxygen was discovered by the Polish alchemist Sendivogius, who considered it the philosophers stone. In the late 17th century, Robert Boyle proved that air is necessary for combustion, English chemist John Mayow refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus. From this he surmised that nitroaereus is consumed in both respiration and combustion, Mayow observed that antimony increased in weight when heated, and inferred that the nitroaereus must have combined with it. Accounts of these and other experiments and ideas were published in 1668 in his work Tractatus duo in the tract De respiratione. Robert Hooke, Ole Borch, Mikhail Lomonosov, and Pierre Bayen all produced oxygen in experiments in the 17th and the 18th century but none of them recognized it as a chemical element. This may have been in part due to the prevalence of the philosophy of combustion and corrosion called the phlogiston theory, which was then the favored explanation of those processes. Established in 1667 by the German alchemist J. J. Becher, one part, called phlogiston, was given off when the substance containing it was burned, while the dephlogisticated part was thought to be its true form, or calx. The fact that a substance like wood gains overall weight in burning was hidden by the buoyancy of the combustion products
10.
Embryo
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An embryo is an early stage of development of a multicellular diploid eukaryotic organism. In general, in organisms that reproduce sexually, an embryo develops from a zygote, the zygote possesses half the DNA of each of its two parents. In plants, animals, and some protists, the zygote will begin to divide by mitosis to produce a multicellular organism, the result of this process is an embryo. First attested in English in the mid-14c, the word embryon derives from Medieval Latin embryo, itself from Greek ἔμβρυον, lit. Young one, which is the neuter of ἔμβρυος, lit, growing in, from ἐν, in and βρύω, swell, be full, the proper Latinized form of the Greek term would be embryum. In animals, the development of the zygote into an embryo proceeds through specific stages of blastula, gastrula. The blastula stage typically features a fluid-filled cavity, the blastocoel, surrounded by a sphere or sheet of cells, in a placental mammal, an ovum is fertilized in a fallopian tube through which it travels into the uterus. An embryo is called a fetus at an advanced stage of development. In humans, this is from the week of gestation. During gastrulation the cells of the blastula undergo coordinated processes of cell division, invasion, in triploblastic organisms, the three germ layers are called endoderm, ectoderm, and mesoderm. The position and arrangement of the layers are highly species-specific, however. For example, in neurogenesis, a subpopulation of cells is set aside to become the brain, spinal cord. Modern developmental biology is extensively probing the molecular basis for every type of organogenesis, including angiogenesis, chondrogenesis, myogenesis, osteogenesis, and many others. In botany, a plant embryo is part of a seed, consisting of precursor tissues for the leaves, stem. Once the embryo begins to germinate — grow out from the seed — it is called a seedling, bryophytes and ferns also produce an embryo, but do not produce seeds. In these plants, the embryo begins its existence attached to the inside of the archegonium on a parental gametophyte from which the egg cell was generated, the structure and development of the rest of the embryo varies by group of plants. Once the embryo has expanded beyond the enclosing archegonium, it is no longer termed an embryo, embryos are used in various fields of research and in techniques of assisted reproductive technology. An egg may be fertilized in vitro and the embryo may be frozen for later use
11.
Micrograph
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A micrograph or photomicrograph is a photograph or digital image taken through a microscope or similar device to show a magnified image of an item. This is opposed to an image, which is at a scale that is visible to the naked eye. Micrography is the practice or art of using microscopes to make photographs, a micrograph contains extensive details that form the features of a microstructure. The neuropathologist Solomon C. Fuller designed and created the first photomicrograph in 1900, micrographs are widely used in all fields of microscopy. A light micrograph or photomicrograph is a micrograph prepared using an optical microscope, at a basic level, photomicroscopy may be performed simply by hooking up a regular camera to a microscope, thereby enabling the user to take photographs at reasonably high magnification. Roman Vishniac was a pioneer in the field of photomicroscopy, specializing in the photography of living creatures in full motion and he also made major developments in light-interruption photography and color photomicroscopy. An electron micrograph is a micrograph prepared using an electron microscope, however, the term electron micrograph is not used in electron microscopy. Digital micrography is a digital picture obtained either directly with a microscope or by scanning of a photomicrograph, digital micrographs are now commonly obtained using a USB microscope attached directly to a home computer or laptop. Today, an add-on three-in-one macro lens which has capability to take wide-angle, fish-eye and macro with 7x, 14x, micrographs usually have micron bars, or magnification ratios, or both. Magnification is a ratio between size of object on a picture and its real size, unfortunately, magnification is somewhat a misleading parameter. It depends on a size of a printed picture. Editors of journals and magazines routinely resize a figure to fit the page, a scale bar, or micron bar, is a bar of known length displayed on a picture. The bar can be used for measurements on a picture, when a picture is resized a bar is also resized. If a picture has a bar, the magnification can be easily calculated, ideally, all pictures destined for publication/presentation should be supplied with a scale bar, the magnification ratio is optional. All but one of the micrographs presented on this page do not have a bar, supplied magnification ratios are likely incorrect. The microscope has been used for scientific discovery. It has also linked to the arts since its invention in the 17th century. At first scientists used the microscope to view and draw objects not visible with the unaided eye, early adopters of the microscope, such as Robert Hooke and Antonie van Leeuwenhoek, were excellent illustrators
12.
Breast
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The breast is one of two prominences located on the upper ventral region of the torso of female primates. In females, it serves as the mammary gland, which produces and secretes milk, both females and males develop breasts from the same embryological tissues. At puberty, estrogens, in conjunction with growth hormone, cause breast development, the breasts of females are typically far more prominent than those of males. Subcutaneous fat covers and envelops a network of ducts that converge on the nipple, at the ends of the ducts are lobules, or clusters of alveoli, where milk is produced and stored in response to hormonal signals. Upon childbirth, the alveoli are stimulated to produce and secrete milk for infants, along with their function in feeding infants, female breasts have social and sexual characteristics. Breasts have been featured in ancient and modern sculpture, art. Female breasts can figure prominently in a perception of her body image. A number of Western cultures associate breasts with sexuality and tend to regard bare breasts in public as immodest or indecent, Breasts and especially the nipples are an erogenous zone on women. The English word breast derives from the Old English word brēost from Proto-Germanic breustam, the breast spelling conforms to the Scottish and North English dialectal pronunciations. The Merriam-Webster Dictionary states that Middle English brest, from Old English brēost, Old Irish brú, Russian bryukho, the first known usage of the term was before the 12th century. A large number of terms for breasts are used in English. Some vulgar slang expressions may be considered to be derogatory or sexist to women, at the front of the chest, the breast tissue can extend from the clavicle to the middle of the sternum. At the sides of the chest, the breast tissue can extend into the axilla, as a mammary gland, the breast is composed of differing layers of tissue, predominantly two types, adipose tissue, and glandular tissue, which affects the lactation functions of the breasts. Morphologically the breast is a cone, with the base at the chest wall and the apex at the nipple, the superficial tissue layer is separated from the skin by 0. 5–2.5 cm of subcutaneous fat. The suspensory Coopers ligaments are fibrous-tissue prolongations that radiate from the superficial fascia to the skin envelope, the female adult breast contains 14–18 irregular lactiferous lobes that converge at the nipple. Milk exits the breast through the nipple, which is surrounded by an area of skin called the areola. The size of the areola can vary widely among women, the areola contains modified sweat glands known as Montgomerys glands. These glands secrete oily fluid that lubricate and protect the nipple during breastfeeding, volatile compounds in these secretions may also serve as an olfactory stimulus for the newborns appetite
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