The thorax ( pl. : thoraces or thoraxes ) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen .
53-609: The Podocopa are a subclass of ostracods . Members of the subclass Podocopa can be differentiated from the other subclass of ostracods ( Myodocopa ) by the morphology of the second antenna : the Podocopa have a relatively long endopod, whereas the Myodocopa have a relatively long exopod. The seventh limb of the Podocopa has a variety of forms or is absent, but is never an annulated worm-like limb (as seen in some Myodocopa). The following orders and unplaced families are recognised in
106-544: A circulatory system where hemolymph sinuses absorbs oxygen through special areas on the inner wall of the carapace. In addition, the respiratory protein hemocyanin has been found in the two orders Myodocopida and Platycopida. Nitrogenous waste is excreted through glands on the maxillae, antennae, or both. The primary sense of ostracods is likely touch, as they have several sensitive hairs on their bodies and appendages. Compound eyes are only found in Myodocopina within
159-488: A light organ in which they produce luminescent chemicals. These ostracods are called "blue sand" or "blue tears" and glow blue in the dark. Their bioluminescent properties made them valuable to the Japanese during World War II , when the Japanese army collected large amounts from the ocean to use as a convenient light for reading maps and other papers at night. The light from these ostracods, called umihotaru in Japanese,
212-418: A more or less pigmented disc, the areola . The apex of a normal heart is in the fifth left intercostal space, three and a half inches from the mid-line. Different types of diseases or conditions that affect the chest include pleurisy , flail chest , atelectasis , and the most common condition, chest pain. These conditions can be hereditary or caused by birth defects or trauma . Any condition that lowers
265-431: A symptom of myocardial infarctions ('heart attack'). If this condition is present in the body, discomfort will be felt in the chest that is similar to a heavy weight placed on the body. Sweating, shortness of breath, lightheadedness , and irregular heartbeat may also be experienced. If a heart attack occurs, the bulk of the damage is caused during the first six hours, so getting the proper treatment as quickly as possible
318-413: A water current between the body and the inner surface of the carapace. Podocopa, the largest subclass, have no gills, heart or circulatory system, so the gas exchange take place all over the surface. The other subclass of ostracods, the Myodocopa, do have a heart, and the family Cylindroleberididae also have 6-8 lamellar gills. Certain other larger members of Myodocopa, even if they don't have gills, have
371-401: Is blocked and traps air. The blockage may be caused by something inside the bronchus , such as a plug of mucus, a tumour , or an inhaled foreign object such as a coin, piece of food, or a toy. It is possible for something outside of the bronchus to cause the blockage. Pneumothorax is the condition where air or gas can build up in the pleural space. It can occur without a known cause or as
424-551: Is eight or nine (but family Entocytheridae and suborder Bairdiocopina has only seven), the Halocyprida goes through six or seven, and Myodocopida only four to six. They are able to produce several offspring many times as adults ( iteroparity ). A variety of fauna prey upon ostracods in both aquatic and terrestrial environments. An example of predation in the marine environment is the action of certain Cytherocopina in
477-473: Is encased by a carapace originating from the head region, and consists of two valves superficially resembling the shell of a clam. A distinction is made between the valve (hard parts) and the body with its appendages (soft parts). Studies of the embryonic development in Myodocopida shows that the bivalved carapace develops from two independent buds of the carapace valves. As the two halves grows, they meet in
530-404: Is generally felt when deep breaths are taken or during a cough. Another non-cardiac cause of chest pain is atelectasis . It is a condition that occurs when a portion of the lung collapses from being airless. When bronchial tubes are blocked, this condition develops and causes patients to feel shortness of breath. The most common cause of atelectasis is when a bronchi that extends from the windpipe
583-526: Is important. Some people, especially those who are elderly or have diabetes, may not have typical chest pain but may have many of the other symptoms of a heart attack. It is important that these patients and their caregivers have a good understanding of heart attack symptoms. Just like with a heart attack, not all chest pain is caused by conditions involving the heart . Chest wall pain can be experienced after an increase in activity. Persons who add exercise to their daily routine generally feel this type of pain at
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#1732797618988636-456: Is in development called mutual ostracod temperature range (MOTR), similar to the mutual climatic range (MCR) used for beetles, which can be used to infer palaeotemperatures. The ratio of oxygen-18 to oxygen-16 (δ18O) and the ratio of magnesium to calcium (Mg/Ca) in the calcite of ostracod valves can be used to infer information about past hydrological regimes, global ice volume and water temperatures. Ecologically, marine ostracods can be part of
689-453: Is known from humid forest soils of South Africa , Australia and New Zealand . As of 2008, around 2000 species and 200 genera of non-marine ostracods are found. However, a large portion of diversity is still undescribed, indicated by undocumented diversity hotspots of temporary habitats in Africa and Australia. Non-marine species have been found to live in sulfidic cave ecosystems such as
742-441: Is no larval stage or metamorphosis ( direct development ). Instead they hatch from the egg as juveniles with the bivalved carapace and at least three functional limbs. As the juvenile grows through a series of molts they acquire more limbs and develop further the already existing ones. They reach sexual maturity in the final instar and then never molts again. The number of instars they go through before adulthood varies. In Podocopa it
795-497: The Guinness World Record for the oldest penis. Males had observable sperm that is the oldest yet seen and, when analysed, showed internal structures and has been assessed as being the largest sperm (per body size) of any animal recorded. It was assessed that the fossilisation was achieved within several days, due to phosphorus in the bat droppings of the cave where the ostracods were living. The body of an ostracod
848-567: The Movile Cave , deep groundwaters, hypersaline waters, acidic waters with pH as low as 3.4, phytotelmata in plants like bromeliads , and in temperatures varying from almost freezing to more than 50 °C in hot springs. Of the known specific and generic diversity of non-marine ostracods, half (1000 species, 100 genera) belongs to one family (of 13 families), Cyprididae . Many Cyprididae occur in temporary water bodies and have drought-resistant eggs, mixed/ parthenogenetic reproduction, and
901-766: The biozonation of marine strata on a local or regional scale, and they are invaluable indicators of paleoenvironments because of their widespread occurrence, small size, easily preservable, generally moulted, calcified bivalve carapaces; the valves are a commonly found microfossil . A find in Queensland, Australia in 2013, announced in May 2014, at the Bicentennary Site in the Riversleigh World Heritage area, revealed both male and female specimens with very well preserved soft tissue. This set
954-431: The cuspidariid clams in detecting ostracods with cilia protruding from inhalant structures, thence drawing the ostracod prey in by a violent suction action. Predation from higher animals also occurs; for example, amphibians such as the rough-skinned newt prey upon certain ostracods. Whale sharks also seem to eat them as part of their filter feeding process. Some ostracods, such as Vargula hilgendorfii , have
1007-408: The zooplankton or (most commonly) are part of the benthos , living on or inside the upper layer of the sea floor. Ostracods has been found as deep as 9,307 m (genus Krithe in family Krithidae ). Subclass Myodocopa and the two podocop orders Palaeocopida and Platycopida are restricted to marine environments (except for Platycopida which have a few brackish species), but we find non-marine forms in
1060-458: The "thoracic skeleton" is a component of the axial skeleton . It consists of the ribs and sternum . The ribs of the thorax are numbered in ascending order from 1–12. 11 and 12 are known as floating ribs because they have no anterior attachment point in particular the cartilage attached to the sternum, as 1 through 7 are, and therefore are termed "floating". Whereas ribs 8 through 10 are termed false ribs as their costal cartilage articulates with
1113-420: The Myodocopa. The order Halocyprida in the same subclass is eyeless. Podocopid ostracods have just a naupliar eye consisting of two lateral ocelli and a single ventral ocellus, but the ventral one is absent in some species. Platycopida was assumed to be completely eyeless, but two species, Keijcyoidea infralittoralis and Cytherella sordida, have been found to both possess a nauplius eye too. A new method
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#17327976189881166-834: The ability to either breathe deeply or to cough is considered a chest disease or condition. Injury to the chest (also referred to as chest trauma, thoracic injury, or thoracic trauma) results in up to 1 / 4 of all deaths due to trauma in the United States. The major pathophysiologies encountered in blunt chest trauma involve derangements in the flow of air, blood, or both in combination. Sepsis due to leakage of alimentary tract contents, as in esophageal perforations, also must be considered. Blunt trauma commonly results in chest wall injuries (e.g., rib fractures). The pain associated with these injuries can make breathing difficult, and this may compromise ventilation. Direct lung injuries, such as pulmonary contusions (see
1219-495: The ability to swim. These biological attributes preadapt them to form successful radiations in these habitats. Male ostracods have two penises , corresponding to two genital openings ( gonopores ) on the female. The individual sperm are often large, and are coiled up within the testis prior to mating; in some cases, the uncoiled sperm can be up to six times the length of the male ostracod itself. Mating typically occurs during swarming, with large numbers of females swimming to join
1272-429: The beginning. It is important to monitor the pain to ensure that it is not a sign of something more serious. Pain can also be experienced in persons who have an upper respiratory infection . This virus is also accompanied by a fever and cough. Shingles is another viral infection that can give symptoms of chest or rib pain before a rash develops. Injuries to the rib cage or sternum is also a common cause of chest pain. It
1325-399: The case of the marine Gigantocypris . The largest known freshwater species is Megalocypris princeps , which reach 8 mm in length. In most cases, their bodies are flattened from side to side and protected by a bivalve -like valve or "shell" made of chitin , and often calcium carbonate. The family Entocytheridae and many planktonic forms do not have calcium carbonate. The hinge of
1378-421: The cause of the pain. While cardiac issues cause feelings of sudden pressure in the chest or a crushing pain in the back, neck, and arms, pain that is felt due to noncardiac issues gives a burning feeling along the digestive tract or pain when deep breaths are attempted. Different people feel pains differently for the same condition. Only a patient truly knows if the symptoms are mild or serious. Chest pain may be
1431-418: The chest does not correspond to that part of the thoracic skeleton that encloses the heart and lungs . All the breadth of the shoulders is due to the shoulder girdle, and contains the axillae and the heads of the humeri . In the middle line the suprasternal notch is seen above, while about three fingers' breadth below it a transverse ridge can be felt, which is known as the sternal angle and this marks
1484-509: The chest, and one of the most common symptoms is chest pain . The word thorax comes from the Greek θώραξ thṓrax " breastplate , cuirass , corslet " via Latin : thorax . In humans and other hominids , the thorax is the chest region of the body between the neck and the abdomen , along with its internal organs and other contents. It is mostly protected and supported by the rib cage , spine , and shoulder girdle . The contents of
1537-418: The costal cartilage of the rib above. The thorax bones also have the main function of protecting the heart, lungs, and major blood vessels in the thorax area, such as the aorta . The anatomy of the chest can also be described through the use of anatomical landmarks . The nipple in the male is situated in front of the fourth rib or a little below; vertically it lies a little external to a line drawn down from
1590-637: The eggs are released directly into the sea, except for a single genus with brood care. In the subclass Podocopa, brood care is only found in Darwinulocopina and some Cytherocopina in the order Podocopida. In the remaining Podocopa it is common to glue the eggs to a firm surface, like vegetation or the substratum. These eggs are often resting eggs, and remain dormant during desiccation and extreme temperatures, only hatching when exposed to more favorable conditions. Species adapted to vernal pools can reach sexual maturity in just 30 days after hatching. There
1643-414: The extinct trilobites , the thorax is one of the three main divisions of the creature's body, each of which is in turn composed of multiple segments. It is the area where the wings and legs attach in insects, or an area of multiple articulating plates in trilobites. In most insects, the thorax itself is composed of three segments; the prothorax , the mesothorax , and the metathorax . In extant insects,
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1696-652: The female is able to read the display to pinpoint the male's location. In one species hundreds of thousands of males synchronize their light display, and when one male creates a pattern of light, the new pattern will spread out as the neighboring males repeat it. Early work indicated that Ostracoda may not be monophyletic , and early molecular phylogeny was ambiguous on this front. Recent combined analyses of molecular and morphological data suggested monophyly in analyses with broadest taxon sampling, but this monophyly had no or very little support (Fig. 1 - bootstrap 0, 17 and 46, often values above 95 are considered sufficient for
1749-569: The four superfamilies Terrestricytheroidea, Cypridoidea, Darwinuloidea, and Cytheroidea in the order Podocopida . Terrestricytheroidea is semi-terrestrial and usually found in brackish and marine-influenced environments such as salt marshes, but not in freshwater. The other three superfamilies also live in freshwater (Darwinuloidea is exclusively non-marine). Of these three, only Cypridoidea have freshwater species able to swim. Representatives living in terrestrial habitats are also found in all three freshwater groups, such as genus Mesocypris which
1802-434: The functional thorax is composed of four segments, and is therefore typically called the mesosoma to distinguish it from the "thorax" of other insects. Each thoracic segment in an insect is further subdivided into various parts, the most significant of which are the dorsal portion (the notum ), the lateral portion (the pleuron ; one on each side), and the ventral portion (the sternum ). In some insects, each of these parts
1855-445: The image below), are frequently associated with major chest trauma and may impair ventilation by a similar mechanism. Chest pain can be the result of multiple issues, including respiratory problems, digestive issues, and musculoskeletal complications. The pain can trigger cardiac issues as well. Not all pain that is felt is associated with the heart, but it should not be taken lightly either. Symptoms can be different depending on
1908-402: The junction between the manubrium and body of the sternum . Level with this line the second ribs join the sternum, and when these are found the lower ribs can often be counted. At the lower part of the sternum, where the seventh or last true ribs join it, the ensiform cartilage begins, and above this there is often a depression known as the pit of the stomach . The bones of the thorax, called
1961-514: The lung or as a shortness of breath. In mammals , the thorax is the region of the body formed by the sternum , the thoracic vertebrae , and the ribs . It extends from the neck to the diaphragm , and does not include the upper limbs . The heart and the lungs reside in the thoracic cavity , as well as many blood vessels . The inner organs are protected by the rib cage and the sternum. Thoracic vertebrae are also distinguished in birds , but not in reptiles . In insects , crustaceans , and
2014-778: The male of at least 75 known species of the Cypridinidae, restricted to the Caribbean, use pulses of light to attract females. Some species are the opposite where the females use pulses of light to attract males. This is seen in one example such as the glow worm . This bioluminiscent courtship display has only evolved once in ostracods, in a cypridinid group named Luxorina that originated at least 151 million years ago. Ostracods with bioluminescent courtship show higher rates of speciation than those who simply use light as protection against predators. The male will continue to swim after releasing its small ball of bioluminescent mucus, but
2067-415: The males. Some species are partially or wholly parthenogenetic . Superfamily Darwinuloidea was assumed to have reproduced asexually for the last 200 million years, but rare males have since been discovered in one of the species. In the subclass Myodocopa, all members of the order Myodocopida have brood care, releasing their offspring as first instars, allowing a pelagic lifestyle. In the order Halocyprida
2120-406: The middle of the clavicle ; in the female it is not so constant. A little below it the lower limit of the great pectoral muscle is seen running upward and outward to the axilla; in the female this is obscured by the breast , which extends from the second to the sixth rib vertically and from the edge of the sternum to the mid-axillary line laterally. The female nipple is surrounded for half an inch by
2173-413: The middle. In Manawa, an ostracod in the order Palaeocopida, the carapace originates as a single element and during growth folds at the midline. The body consists of a head and thorax , separated by a slight constriction. Unlike many other crustaceans, the body is not clearly divided into segments . Most species have completely or partly lost their trunk segmentation, and there are no boundaries between
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2226-460: The most common arthropods in the fossil record" with fossils being found from the early Ordovician to the present. An outline microfaunal zonal scheme based on both Foraminifera and Ostracoda was compiled by M. B. Hart. Freshwater ostracods have even been found in Baltic amber of Eocene age, having presumably been washed onto trees during floods. Ostracods have been particularly useful for
2279-417: The prothorax never has wings, though legs are always present in adults; wings (when present) are restricted to at least the mesothorax, and typically also the metathorax, though the wings may be reduced or modified on either or both segments. In the apocritan Hymenoptera , the first abdominal segment is fused to the metathorax, where it forms a structure known as the propodeum . Accordingly, in these insects,
2332-413: The result of a lung disease or acute lung injury. The size of the pneumothorax changes as air or gas builds up, so a medical procedure can release the pressure with a needle. If it is untreated, blood flow can be interrupted and cause a drop in blood pressure known as tension pneumothorax. It is possible for smaller cases to clear up on their own. Symptoms of this condition are often felt only on one side of
2385-463: The second and third pair are absent in suborder Cladocopina . In the Myodocopina the third pair is a multisegmented cleaning organ that resembles a worm. Their external genitals seem to originate from the fusion of three to five appendages. The two "rami", or projections, from the tip of the tail point downward and slightly forward from the rear of the shell. All ostracods have a pair of "ventilatory appendages" that beat rhythmically, which create
2438-557: The subclass Podocopa: This Ostracod -related article is a stub . You can help Misplaced Pages by expanding it . Ostracod Ostracods , or ostracodes, are a class of the Crustacea (class Ostracoda ), sometimes known as seed shrimp . Some 33,000 species (only 13,000 of which are extant ) have been identified, grouped into 7 valid orders. They are small crustaceans, typically around 1 mm (0.04 in) in size, but varying from 0.2 to 30 mm (0.008 to 1 in) in
2491-491: The taxon support). Class Ostracoda is divided into following living clades: Thorax In insects , crustaceans , and the extinct trilobites , the thorax is one of the three main divisions of the body, each in turn composed of multiple segments. The human thorax includes the thoracic cavity and the thoracic wall . It contains organs including the heart , lungs , and thymus gland, as well as muscles and various other internal structures. Many diseases may affect
2544-421: The thorax and abdomen , and it has therefore been impossible to tell if the first pair of limbs after the maxillae belongs to the head or the thorax. With a few exception, like platycopids which have an 11-segmented trunk, the abdomen in ostracods has no visible segments. The head is the largest part of the body, and bears four pairs of appendages. Two pairs of well-developed antennae are used to swim through
2597-453: The thorax include the heart and lungs (and the thymus gland); the major and minor pectoral muscles, trapezius muscles , and neck muscle; and internal structures such as the diaphragm , the esophagus , the trachea , and a part of the sternum known as the xiphoid process . Arteries and veins are also contained – ( aorta , superior vena cava , inferior vena cava and the pulmonary artery ); bones (the shoulder socket containing
2650-457: The two valves is in the upper (dorsal) region of the body. Ostracods are grouped together based on shell and soft part morphology, and molecular studies have not unequivocally supported the group's monophyly . They have a wide range of diets, and the class includes carnivores, herbivores, scavengers and filter feeders, but most ostracods are deposit feeders. Ostracod comes from the Greek óstrakon meaning shell or tile. Ostracods are "by far
2703-414: The upper part of the humerus , the scapula , sternum , thoracic portion of the spine , collarbone , and the rib cage and floating ribs ). External structures are the skin and nipples . In the human body , the region of the thorax between the neck and diaphragm in the front of the body is called the chest. The corresponding area in an animal can also be referred to as the chest. The shape of
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#17327976189882756-463: The water. In addition, there are a pair of mandibles and a pair of maxillae . The thorax has three primary pairs of appendages. The first of these has different functions in different groups. It can be used for feeding (Cypridoidea) or for walking (Cytheroidea), and in some species it has evolved into a male clasping organ. The second pair is mainly used for locomotion, and the third is used for walking or cleaning, but can also be reduced or absent. Both
2809-532: Was sufficient to read by but not bright enough to give away troops' position to enemies. Bioluminescence has evolved twice in ostracods; once in Cypridinidae , and once in Halocyprididae . In bioluminescent Halocyprididae a green light is produced within carapace glands, and in Cypridinidae a blue light is produced and extruded from the upper lip. Most species use the light as predation defense, but
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