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103-574: General surgeons may sub-specialise into one or more of the following disciplines: In many parts of the world including North America , Australia and the United Kingdom , the overall responsibility for trauma care falls under the auspices of general surgery. Some general surgeons obtain advanced training in this field (most commonly surgical critical care) and specialty certification surgical critical care. General surgeons must be able to deal initially with almost any surgical emergency. Often, they are

206-550: A writing system , built huge pyramids and temples , had a complex calendar , and developed the concept of zero around 400 CE. The first recorded European references to North America are in Norse sagas where it is referred to as Vinland . The earliest verifiable instance of pre-Columbian trans-oceanic contact by any European culture with the North America mainland has been dated to around 1000 CE. The site , situated at

309-564: A Whipple's (pancreaticoduodenectomy + hemigastrectomy), but patients benefit from improved recovery of weight after a PPPD, so this should be performed when the tumour does not involve the stomach and the lymph nodes along the gastric curvatures are not enlarged. Compared to the standard Whipple procedure, the pylorus preserving pancreaticoduodenectomy technique is associated with shorter operation time and less intraoperative blood loss, requiring less blood transfusion. Post-operative complications, hospital mortality and survival do not differ between

412-523: A cardiothoracic surgery fellowship (typically 2–3 years). However, new programmes are currently offering cardiothoracic surgery as a residency (6–8 years). Pediatric surgery is a subspecialty of general surgery. Pediatric surgeons do surgery on patients under age 18. Pediatric surgery is 5–7 years of residency and a 2-3 year fellowship. In the 2000s, minimally invasive surgery became more prevalent. Considerable enthusiasm has been built around robot-assisted surgery (also known as robotic surgery ), despite

515-479: A factor of almost four depending on the number of times the surgeon has previously performed the procedure. de Wilde et al. have reported statistically significant mortality reductions concurrent with centralization of the procedure in the Netherlands. One study reported actual risk to be 2.4 times greater than the risk reported in the medical literature, with additional variation by type of institution. Three of

618-424: A general surgical oncologist (a specialty of a general surgeon), but thoracic surgical oncologists, gynecologist and so forth can all be considered surgeons who specialize in treating cancer patients. The importance of training surgeons who sub-specialize in cancer surgery lies in evidence, supported by a number of clinical trials, that outcomes in surgical cancer care are positively associated to surgeon volume (i.e.,

721-606: A lack of data suggesting it has significant benefits that justify its cost. In Canada, Australia, New Zealand, and the United States general surgery is a five to seven year residency and follows completion of medical school , either MD, MBBS, MBChB , or DO degrees. In Australia and New Zealand, a residency leads to eligibility for Fellowship of the Royal Australasian College of Surgeons . In Canada, residency leads to eligibility for certification by and Fellowship of

824-432: A particularly severe form of diabetes mellitus called brittle diabetes . Sometimes the pancreaticojejunostomy may not hold properly after the completion of the operation and infection may spread inside the patient. This may lead to another operation shortly thereafter in which the remainder of the pancreas (and sometimes the spleen ) is removed to prevent further spread of infection and possible morbidity . In recent years

927-648: A period of mountain building called the Laramide orogeny , between 80 and 55 mya. The formation of the Isthmus of Panama that connected the continent to South America arguably occurred approximately 12 to 15 mya, and the Great Lakes (as well as many other northern freshwater lakes and rivers) were carved by receding glaciers about 10,000 years ago. North America is the source of much of what humanity knows about geologic time periods. The geographic area that would later become

1030-571: A powerful earthquake killed seven people in 2009. Volcanic eruptions are common in the region. In 1968, the Arenal Volcano , in Costa Rica, erupted and killed 87 people. Fertile soils from weathered volcanic lavas have made it possible to sustain dense populations in agriculturally productive highland areas. Central America has many mountain ranges ; the longest are the Sierra Madre de Chiapas ,

1133-540: A variety of reactions, including curiosity, trading, cooperation, resignation, and resistance. The indigenous population declined substantially following European arrival, primarily due to the introduction of Eurasian diseases, such as smallpox , to which the indigenous peoples lacked immunity, and because of violent conflicts with Europeans. Indigenous culture changed significantly and their affiliation with political and cultural groups also changed. Several linguistic groups died out , and others changed quite quickly. On

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1236-514: A wide variety of major and minor colon and rectal diseases including inflammatory bowel diseases (such as ulcerative colitis or Crohn's disease ), diverticulitis , colon and rectal cancer, gastrointestinal bleeding and hemorrhoids. General surgeons can specialise in Upper Gastro-intestinal (or foregut ) surgery, which includes the surgical treatment of diseases of the stomach and oesophagus , liver , pancreas and gallbladder . In

1339-534: Is a physiologic response to abdominal surgery, including the Whipple procedure. While post-operative ileus is typically self-limited, prolonged post-operative ileus occurs when patients develop nausea, abdominal distention, pain or intolerance of food by mouth. Various measures are taken in the immediate post-operative period to minimize prolonged post-operative ileus. A nasogastric tube is typically maintained to suction, to drain gastric and intestinal contents. Ambulation

1442-640: Is a very large continent that extends from north of the Arctic Circle to south of the Tropic of Cancer . Greenland, along with the Canadian Shield , is tundra with average temperatures ranging from 10 to 20 °C (50 to 68 °F), but central Greenland is composed of a very large ice sheet. This tundra radiates throughout Canada, but its border ends near the Rocky Mountains (but still contains Alaska) and at

1545-400: Is also derived from the celiac artery . The reason for the removal of the duodenum along with the head of the pancreas is that they share the same arterial blood supply (the superior pancreaticoduodenal artery and inferior pancreaticoduodenal artery). These arteries run through the head of the pancreas so that both organs must be removed if the single blood supply is severed. If only the head of

1648-511: Is an ancient craton which forms the geologic core of North America; it formed between 1.5 and 1.0 billion years ago during the Proterozoic eon. The Canadian Shield is the largest exposure of this craton. From the Late Paleozoic to Early Mesozoic eras, North America was joined with the other modern-day continents as part of the supercontinent Pangaea , with Eurasia to its east. One of

1751-403: Is an important first step as the presence of active metastatic disease is a contraindication to performing the operation. The vascular supply of the pancreas is from the celiac artery via the superior pancreaticoduodenal artery and the superior mesenteric artery from the inferior pancreaticoduodenal artery . There are additional smaller branches given off by the right gastric artery which

1854-920: Is bordered to the north by the Arctic Ocean , to the east by the Atlantic Ocean , to the southeast by South America and the Caribbean Sea , and to the west and south by the Pacific Ocean . The region includes the Bahamas , Bermuda , Canada , the Caribbean , Central America , Clipperton Island , Greenland , Mexico , Saint Pierre and Miquelon , Turks and Caicos Islands , and the United States . North America covers an area of about 24,709,000 square kilometers (9,540,000 square miles), representing approximately 16.5% of

1957-468: Is encouraged to stimulate return of bowel function. Use of opioid medications , which interfere with intestinal motility, is limited. This procedure was originally described by Alessandro Codivilla , an Italian surgeon, in 1898. The first resection for a periampullary cancer was performed by the German surgeon Walther Kausch in 1909 and described by him in 1912. It is often called Whipple's procedure or

2060-535: Is in present-day Panama at the Darien Gap on the Colombia -Panama border, placing almost all of Panama within North America. Alternatively, some geologists physiographically locate its southern limit at the Isthmus of Tehuantepec , Mexico, with Central America extending southeastward to South America from this point. The Caribbean islands, or West Indies, are considered part of North America. The continental coastline

2163-630: Is long and irregular. The Gulf of Mexico is the largest body of water indenting the continent, followed by Hudson Bay . Others include the Gulf of Saint Lawrence and the Gulf of California . Before the Central American isthmus formed, the region had been underwater. The islands of the West Indies delineate a submerged former land bridge , which had connected North and South America via what are now Florida and Venezuela . There are several islands off

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2266-471: Is now divided into two further phases (phases 2 and 3). Trainees are expected to declare a sub-specialty before the end of phase 2, and training during phase 3 focuses on that sub-specialty. Before the end of HST, the examination for Fellowship of the Royal College of Surgeons (FRCS) must be taken in general surgery plus the subspeciality. Upon completion of training, the surgeon will be eligible for entry on

2369-439: Is now evolving from this concept (see below). Gallbladders, appendices, and colons can all be removed with this technique. Hernias are also able to be repaired laparoscopically. Bariatric surgery can be performed laparoscopically and there a benefits of doing so to reduce wound complications in obese patients. General surgeons that are trained today are expected to be proficient in laparoscopic procedures. General surgeons treat

2472-548: Is part of North America geographically. In a geologic sense, Bermuda is not part of the Americas, but an oceanic island that was formed on the fissure of the Mid-Atlantic Ridge over 100 million years ago (mya). The nearest landmass to it is Cape Hatteras , North Carolina . However, Bermuda is often thought of as part of North America, especially given its historical, political and cultural ties to Virginia and other parts of

2575-431: Is particularly true of complex cancer resections such as pancreaticoduodenectomy for pancreatic cancer, and gastrectomy with extended (D2) lymphadenectomy for gastric cancer. Surgical oncology is generally a 2-year fellowship following completion of a general surgery residency (5–7 years). Most cardiothoracic surgeons in the U.S. (D.O. or M.D.) first complete a general surgery residency (typically 5–7 years), followed by

2678-686: Is the Morrison Formation of the western U.S. Canada is geologically one of the oldest regions in the world, with more than half of the region consisting of Precambrian rocks that have been above sea level since the beginning of the Palaeozoic era. Canada's mineral resources are diverse and extensive. Across the Canadian Shield and in the north there are large iron, nickel, zinc , copper, gold, lead, molybdenum , and uranium reserves. Large diamond concentrations have been recently developed in

2781-516: Is the humid subtropical climate . This area has the wettest cities in the contiguous U.S. , with annual precipitation reaching 67 in (1,700 mm) in Mobile, Alabama . Stretching from the borders of the humid continental and subtropical climates, and going west to the Sierra Nevada , south to the southern tip of Durango , north to the border with tundra climate, the steppe / desert climates are

2884-600: Is undertaken by Hepatobiliary and Pancreatic Surgery sub-specialists. General surgeons perform a majority of all non-cosmetic breast surgery from lumpectomy to mastectomy , especially pertaining to the evaluation, diagnosis and treatment of breast cancer . General surgeons can perform vascular surgery if they receive special training and certification in vascular surgery. Otherwise, these procedures are typically performed by vascular surgery specialists. However, general surgeons are capable of treating minor vascular disorders. General surgeons are trained to remove all or part of

2987-705: The Americas at least 20,000 years ago, but various evidence points to possibly earlier dates. The Paleo-Indian period in North America followed the Last Glacial Period, and lasted until about 10,000 years ago when the Archaic period began. The classic stage followed the Archaic period, and lasted from approximately the 6th to 13th centuries. Beginning in 1000 AD, the Norse were the first Europeans to begin exploring and ultimately colonizing areas of North America. In 1492,

3090-551: The Bering Strait during the Early-Middle Holocene . Prior to the arrival of European explorers and colonists in North America, the natives of North America were divided into many different polities, ranging from small bands of a few families to large empires. They lived in several culture areas , which roughly correspond to geographic and biological zones that defined the representative cultures and lifestyles of

3193-576: The British Columbia Coast , Western Canada , and Northern Canada . In the U.S., they include New England , the Mid-Atlantic , South Atlantic states , East North Central states , West North Central states , East South Central states , West South Central states , Mountain states , and Pacific states . The Great Lakes region and the Pacific Northwest include areas in both Canada and

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3296-863: The Caribbean Plate , whereas the Juan de Fuca Plate and Cocos Plate border the North American Plate on its western frontier. The continent can be divided into four great regions (each of which contains many subregions): the Great Plains stretching from the Gulf of Mexico to the Canadian Arctic ; the geologically young, mountainous west, including the Rocky Mountains , the Great Basin , California , and Alaska ;

3399-553: The Cordillera Isabelia , and the Cordillera de Talamanca . Between the mountain ranges lie fertile valleys that are suitable for the people; in fact, most of the population of Honduras, Costa Rica, and Guatemala live in valleys. Valleys are also suitable for the production of coffee, beans, and other crops. The indigenous peoples of the Americas have many creation myths , based on which they assert that they have been present on

3502-498: The Earth 's land area and 4.8% of its total surface area. It is the third-largest continent by size after Asia and Africa , and the fourth-largest continent by population after Asia, Africa, and Europe . As of 2021 , North America's population was estimated as over 592 million people in 23 independent states , or about 7.5% of the world's population. In human geography , the terms "North America" and "North American" can refer to Canada,

3605-459: The East Coast to eastern North Dakota , and stretching down to Kansas , is the humid continental climate featuring intense seasons, with a large amount of annual precipitation, with places like New York City averaging 50 in (1,300 mm). Starting at the southern border of the humid continental climate and stretching to the Gulf of Mexico (whilst encompassing the eastern half of Texas)

3708-658: The GMC Specialist Register. They may then apply to work both in the NHS and independent sector as a consultant surgeon, although many trainees complete further fellowships. The implementation of the European Working Time Directive limited UK surgical residents to an average 48-hour working week. North America North America is a continent in the Northern and Western Hemispheres . North America

3811-608: The Inuit of the high Arctic arrived in North America much later than other native groups, evidenced by the disappearance of Dorset culture artifacts from the archaeological record and their replacement by the Thule people . During the thousands of years of native habitation on the continent, cultures changed and shifted. One of the oldest yet discovered is the Clovis culture (c. 9550–9050 BCE) in modern New Mexico . Later groups include

3914-694: The Mississippian culture and related Mound building cultures, found in the Mississippi River valley and the Pueblo culture of what is now the Four Corners . The more southern cultural groups of North America were responsible for the domestication of many common crops now used around the world, such as tomatoes, squash , and maize . As a result of the development of agriculture in the south, many other cultural advances were made there. The Mayans developed

4017-583: The Royal College of Physicians and Surgeons of Canada , while in the United States, completion of a residency in general surgery leads to eligibility for board certification by the American Board of Surgery or the American Osteopathic Board of Surgery which is also required upon completion of training for a general surgeon to have operating privileges at most hospitals in the United States. In

4120-662: The United Kingdom , surgical trainees may apply to enter training after five years of medical school and two years of the Foundation Programme . During the two year core surgical training programme ("phase 1"), doctors are required to sit the Membership of the Royal College of Surgeons (MRCS) examination. On award of the MRCS by one of the four surgical colleges, surgeons may hold the title ' Mister ' or ' Miss / Ms. / Mrs ' rather than doctor. This tradition dates back hundreds of years in

4223-623: The Whipple procedure , after the American surgeon Allen Whipple who devised an improved version of the surgery in 1935 while at Columbia-Presbyterian Medical Center in New York and subsequently came up with multiple refinements to his technique. Fingerhut et al. argue that while the terms pancreatoduodenectomy and pancreaticoduodenectomy are often used interchangeably in the medical literature, scrutinizing their etymology yields different definitions for

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4326-480: The first official name given to Mexico. North America includes several regions and subregions, each of which have their own respective cultural, economic, and geographic regions. Economic regions include several regions formalized in 20th- and 21st-century trade agreements, including NAFTA between Canada , Mexico , and the United States , and CAFTA between Central America , the Dominican Republic , and

4429-582: The inferior vena cava . These structures are important to consider in this operation especially if done for resection of a tumor located in the head of the pancreas. Pancreaticoduodenectomy is most often performed as a curative treatment for periampullary cancer , which includes cancer of the bile duct, duodenum, ampulla or head of the pancreas. The shared blood supply of the pancreas, duodenum and common bile duct necessitates en bloc resection of these multiple structures. Other indications for pancreaticoduodenectomy include chronic pancreatitis , benign tumors of

4532-453: The 1490s, building cities, putting the resident indigenous populations to work, raising crops for Spanish settlers and panning gold to enrich the Spaniards. Much of the indigenous population died due to disease and overwork, spurring the Spaniards on to claim new lands and peoples. An expedition under the command of Spanish settler, Hernán Cortés , sailed westward in 1519 to what turned out to be

4635-615: The Arctic, making Canada one of the world's largest producers. Throughout the Shield, there are many mining towns extracting these minerals. The largest, and best known, is Sudbury , Ontario. Sudbury is an exception to the normal process of forming minerals in the Shield since there is significant evidence that the Sudbury Basin is an ancient meteorite impact crater . The nearby, but less-known Temagami Magnetic Anomaly has striking similarities to

4738-635: The Caribbean islands. France took the western half of Hispaniola and developed Saint-Domingue as a cane sugar producing colony worked by black slave labor. Britain took Barbados and Jamaica , and the Dutch and Danes took islands previously claimed by Spain. Britain did not begin settling on the North American mainland until a hundred years after the first Spanish settlements, since it sought first to control nearby Ireland . The first permanent English settlement

4841-616: The Cod fish", in reference to the abundance of cod fish on the East Coast . Waldseemüller used the Latin version of Vespucci's name, Americus Vespucius, in its feminine form of "America", following the examples of "Europa", "Asia", and "Africa". Americus originated from Medieval Latin Emericus (see Saint Emeric of Hungary ), coming from the Old High German name Emmerich . Map makers later extended

4944-419: The North America's southeastern coast, Spanish explorer Juan Ponce de León , who had accompanied Columbus's second voyage, visited and named in 1513 La Florida . As the colonial period unfolded, Spain, England, and France appropriated and claimed extensive territories in North America eastern and southern coastlines. Spain established permanent settlements on the Caribbean islands of Hispaniola and Cuba in

5047-472: The Sudbury Basin. Its magnetic anomalies are very similar to the Sudbury Basin, and so it could be a second metal-rich impact crater. The Shield is also covered by vast boreal forests that support an important logging industry. The United States can be divided into twelve main geological provinces: Each province has its own geologic history and unique features. The geology of Alaska is typical of that of

5150-522: The U.S. North America occupies the northern portion of the landmass generally referred to as the New World, the Western Hemisphere , the Americas, or simply America, which, in many countries, is considered a single continent with North America a subcontinent . North America is the third-largest continent by area after Asia and Africa . North America's only land connection to South America

5253-508: The UK, Upper GI surgeons can subspecialise further as benign surgeons, dealing with hiatus hernias and gallbladder diseases, bariatric surgeons, providing surgical care for weight management and metabolic diseases, or oesophago-gastric surgeons, dealing with complex problems related to the upper gastrointestinal tract (the foregut), including cancer. Surgical care of complex liver and pancreatic problems (including liver cancer and pancreatic cancer )

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5356-547: The United Kingdom from when only physicians attended medical school and surgeons did not, but were rather associated with barbers in the Barber Surgeon's Guild. The tradition is also present in many Commonwealth countries including New Zealand and some states of Australia . After completion of phase 1 training, trainees may apply for a nationally awarded Higher Surgical Training (HST) programme, which lasts six years and

5459-429: The United States has been the source of more varieties of dinosaurs than any other modern country. According to paleontologist Peter Dodson, this is primarily due to stratigraphy, climate and geography, human resources, and history. Much of the Mesozoic Era is represented by exposed outcrops in the many arid regions of the continent. The most significant Late Jurassic dinosaur-bearing fossil deposit in North America

5562-452: The United States, Mexico, and Greenland or, alternatively, Canada, Greenland and the US (Mexico being classified as part of Latin America ) or simply Canada and the US (Greenland being classified as either Arctic or European (due to its political status as a part of Denmark) and Mexico classified as Latin American). It is unknown with certainty how and when first human populations first reached North America. People were known to live in

5665-550: The United States, and Mexico. France , Italy , Portugal , Spain , Romania , Greece , and the countries of Latin America use a six-continent model , with the Americas viewed as a single continent and North America designating a subcontinent comprising Canada , the United States , Mexico, and Saint Pierre and Miquelon (politically part of France), and often including Greenland and Bermuda . North America has historically been known by other names, including Spanish North America, New Spain , and América Septentrional,

5768-527: The United States. North America is divided linguistically and culturally into two primary regions, Anglo-America and Latin America . Anglo-America includes most of North America, Belize , and Caribbean islands with English -speaking populations. There are also regions, including Louisiana and Quebec , with large Francophone populations; in Quebec , French is the official language. . The southern portion of North America includes Central America and non-English speaking Caribbean nations. The north of

5871-407: The Whipple procedure. Surgery may follow neoadjuvant chemotherapy , which aims to shrink the tumor and increase the likelihood of complete resection. Post-operative death and complications associated with pancreaticoduodenectomy have become less common, with rates of post-operative mortality falling from 30 to 10% in the 1980s to less than 5% in the 2000s. Ampullary cancer arises from the lining of

5974-416: The ampulla of Vater. Duodenal cancer arises from the lining of the duodenal mucosa. Majority of duodenal cancers originate in the second part of the duodenum, where ampulla is located. Cholangiocarcinoma , or cancer of the bile duct , is an indication for the Whipple procedure when the cancer is present in the distal biliary system, usually the common bile duct that drains into the duodenum. Depending on

6077-450: The area are often removed during the operation as well (lymphadenectomy). However, not all lymph nodes are removed in the most common type of pancreaticoduodenectomy because studies showed that patients did not benefit from the more extensive surgery. At the very beginning of the procedure, after the surgeons have gained access to the abdomen, the surfaces of the peritoneum and the liver are inspected for disease that has metastasized. This

6180-435: The area had shifted to the Aztec Empire , whose capital city Tenochtitlan was located further north in the Valley of Mexico . The Aztecs were conquered in 1521 by Hernán Cortés . During the so-called Age of Discovery , Europeans explored overseas and staked claims to various parts of North America, much of which was already settled by indigenous peoples. Upon Europeans' arrival in the " New World ", indigenous peoples had

6283-458: The common bile duct and jejunum) is made. This new connection may leak in 1–2% of operations. As this complication is fairly common, it is normal in this procedure for the surgeon to leave a drain in place at the end. This allows for detection of a bile leak via elevated bilirubin in the fluid drained. Pancreatic leak or pancreatic fistula, defined as fluid drained after postoperative day 3 that has an amylase content greater than or equal to 3 times

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6386-432: The continent maintains recognized regions as well. In contrast to the common definition of North America, which encompasses the whole North American continent, the term "North America" is sometimes used more narrowly to refer only to four nations, Canada, Greenland, Mexico, and the U.S. The U.S. Census Bureau includes Saint Pierre and Miquelon, but excludes Mexico from its definition. The term Northern America refers to

6489-452: The continent's coasts; principally, the Arctic Archipelago, the Bahamas , Turks and Caicos , the Greater and Lesser Antilles , the Aleutian Islands (some of which are in the Eastern Hemisphere proper), the Alexander Archipelago , the many thousand islands of the British Columbia Coast, and Newfoundland. Greenland , a self-governing Danish island, and the world's largest , is on the same tectonic plate (the North American Plate ) and

6592-410: The continent. The vast majority of North America is on the North American Plate. Parts of western Mexico, including Baja California, and of California , including the cities of San Diego , Los Angeles , and Santa Cruz , lie on the eastern edge of the Pacific Plate , with the two plates meeting along the San Andreas Fault . The southernmost portion of the continent and much of the West Indies lie on

6695-604: The cordillera, while the major islands of Hawaii consist of Neogene volcanics erupted over a hot spot . Central America is geologically active with volcanic eruptions and earthquakes occurring from time to time. In 1976 Guatemala was hit by a major earthquake , killing 23,000 people; Managua, the capital of Nicaragua, was devastated by earthquakes in 1931 and 1972, the last one killing about 5,000 people; three earthquakes devastated El Salvador, one in 1986 and two in 2001; one earthquake devastated northern and central Costa Rica in 2009, killing at least 34 people; in Honduras

6798-514: The cultures of the region commonly reflect Western traditions . However, relatively small parts of North America in Canada, the United States, Mexico, and Central America have indigenous populations that continue adhering to their respective pre-European colonial cultural and linguistic traditions. The Americas were named after the Italian explorer Amerigo Vespucci by German cartographers Martin Waldseemüller and Matthias Ringmann . Vespucci explored South America between 1497 and 1502, and

6901-447: The driest in the U.S. Highland climates cut from north to south of the continent, where subtropical or temperate climates occur just below the tropics, as in central Mexico and Guatemala . Tropical climates appear in the island regions and in the subcontinent's bottleneck, found in countries and states bathed by the Caribbean Sea or to the south of the Gulf of Mexico and the Pacific Ocean . Precipitation patterns vary across

7004-408: The end of the Canadian Shield, near the Great Lakes . Climate west of the Cascade Range is described as being temperate weather with average precipitation 20 inches (510 millimeters). Climate in coastal California is described to be Mediterranean , with average temperatures in cities like San Francisco ranging from 57 to 70 °F (14 to 21 °C) over the course of the year. Stretching from

7107-544: The exploratory voyages of Christopher Columbus led to a transatlantic exchange , including migrations of European settlers during the Age of Discovery and the early modern period . Present-day cultural and ethnic patterns reflect interactions between European colonists, indigenous peoples , enslaved Africans , immigrants from Europe, Asia, and descendants of these respective groups. Europe's colonization in North America led to most North Americans speaking European languages, such as English , Spanish , and French , and

7210-421: The first American inhabitants sailed from Beringia some 13,000 years ago, with widespread habitation of the Americas during the end of the Last Glacial Period , in what is known as the Late Glacial Maximum , around 12,500 years ago. The oldest petroglyphs in North America date from 15,000 to 10,000 years before present. Genetic research and anthropology indicate additional waves of migration from Asia via

7313-494: The first port of call to critically ill or gravely injured patients, and must perform a variety of procedures to stabilize such patients, such as thoracostomy, cricothyroidotomy , compartment fasciotomies and emergency laparotomy or thoracotomy to stanch bleeding. They are also called upon to staff surgical intensive care units or trauma intensive care units. All general surgeons are trained in emergency surgery. Bleeding, infections, bowel obstructions and organ perforations are

7416-843: The geographic center of either the 50 states, the conterminous United States, or the North American continent." Nonetheless, there is a 4.6-meter (15 ft) field stone obelisk in Rugby claiming to mark the center. The North American continental pole of inaccessibility is located 1,650 km (1,030 mi) from the nearest coastline, between Allen and Kyle, South Dakota at 43°22′N 101°58′W  /  43.36°N 101.97°W  / 43.36; -101.97  ( Pole of Inaccessibility North America ) . Canada can be divided into roughly seven physiographic divisions: The lower 48 U.S. states can be divided into roughly eight physiographic divisions: Mexico can be divided into roughly fifteen physiographic divisions: North America

7519-424: The head of the pancreas also necessitates removal of the duodenum , proximal jejunum , gallbladder , and, occasionally, part of the stomach . The most common technique of a pancreaticoduodenectomy consists of the en bloc removal of the distal segment (antrum) of the stomach, the first and second portions of the duodenum, the head of the pancreas , the common bile duct , and the gallbladder . Lymph nodes in

7622-414: The head of the pancreas can relieve pancreatic duct obstruction associated with chronic pancreatitis. Damage to the pancreas and duodenum from blunt abdominal trauma is uncommon. In rare cases when this pattern of trauma has been reported, it has been seen as a result of a lap belt in motor vehicle accidents. Pancreaticoduodenectomy has been performed when abdominal trauma has resulted in bleeding around

7725-419: The indigenous people who lived there, including the bison hunters of the Great Plains and the farmers of Mesoamerica . Native groups also are classified by their language families , which included Athapascan and Uto-Aztecan languages. Indigenous peoples with similar languages did not always share the same material culture , however, and were not necessarily always allies. Anthropologists speculate that

7828-422: The initial part of a pancreaticoduodenectomy that was cancelled due to metastatic disease. Further contraindications include encasement of major vessels (such as celiac artery, inferior vena cava, or superior mesenteric artery) as mentioned above. Clinical trials have failed to demonstrate significant survival benefits of total pancreatectomy , mostly because patients who submit to this operation tend to develop

7931-460: The land since its creation, but there is no evidence that humans evolved there. The specifics of the initial settlement of the Americas by ancient Asians are subject to ongoing research and discussion. The traditional theory has been that hunters entered the Bering Land Bridge between eastern Siberia and present-day Alaska from 27,000 to 14,000 years ago. A growing viewpoint is that

8034-417: The location and extension of the cholangiocarcinoma, curative surgical resection may require hepatectomy , or removal of part of the liver, with or without pancreaticoduodenectomy. Treatment of chronic pancreatitis typically includes pain control and management of exocrine insufficiency . Intractable abdominal pain is the main surgical indication for surgical management of chronic pancreatitis. Removal of

8137-547: The main problems they deal with. Cholecystectomy , the surgical removal of the gallbladder, is one of the most common surgical procedures done worldwide. This is most often done electively, but the gallbladder can become acutely inflamed and require an emergency operation. Infections and rupture of the appendix and small bowel obstructions are other common emergencies. This is a relatively new specialty dealing with minimal access techniques using cameras and small instruments inserted through 3- to 15-mm incisions. Robotic surgery

8240-640: The mainland in Mexico. With local indigenous allies, the Spanish conquered the Aztec empire in central Mexico in 1521. Spain then established permanent cities in Mexico, Central America, and Spanish South America in the sixteenth century. Once Spaniards conquered the high civilization of the Aztecs and Incas, the Caribbean was a backwater of the Spanish empire. Other European powers began to intrude on areas claimed by Spain, including

8343-912: The middle into the main range of the Rockies and the coast ranges in California , Oregon , Washington , and British Columbia , with the Great Basin—a lower area containing smaller ranges and low-lying deserts—in between. The highest peak is Denali in Alaska. The U.S. Geographical Survey (USGS) states that the geographic center of North America is "6 miles [10 km] west of Balta, Pierce County, North Dakota " at about 48°10′N 100°10′W  /  48.167°N 100.167°W  / 48.167; -100.167 , about 24 kilometers (15 mi) from Rugby, North Dakota . The USGS further states that "No marked or monumented point has been established by any government agency as

8446-402: The more cancer cases a surgeon treats, the more proficient he or she becomes, and his or her patients experience improved survival rates as a result). This is another controversial point, but it is generally accepted, even as common sense, that a surgeon who performs a given operation more often, will achieve superior results when compared with a surgeon who rarely performs the same procedure. This

8549-426: The most common post-operative complications are delayed gastric emptying, bile leak, and pancreatic leak. Delayed gastric emptying, normally defined as an inability to tolerate a regular diet by the end of the first post-op week and the requirement for nasogastric tube placement, occurs in approximately 17% of operations. During the surgery, a new biliary connection (normally a choledochal-jejunal anastamosis connecting

8652-450: The name America to North America. In 1538, Gerardus Mercator used the term America on his world map of the entire Western Hemisphere . On his subsequent 1569 map , Mercator called North America "America or New India" ( America sive India Nova ). The Spanish Empire called its territories in North and South America "Las Indias", and the name given to the state body that oversaw the region

8755-493: The northernmost countries and territories of North America: the U.S., Bermuda , Canada, Greenland, and St. Pierre and Miquelon. Although the term does not refer to a unified region, Middle America includes Mexico, Central America, and the Caribbean. North America's largest countries by land area are Canada and the U.S., both of which have well-defined and recognized subregions. In Canada, these include (from east to west) Atlantic Canada , Central Canada , Canadian Prairies ,

8858-440: The northernmost extent of the island named Newfoundland , has provided unmistakable evidence of Norse settlement. Norse explorer Leif Erikson (c. 970–1020 CE) is thought to have visited the area. Erikson was the first European to make landfall on the continent (excluding Greenland). The Mayan culture was still present in southern Mexico and Guatemala when the Spanish conquistadors arrived, but political dominance in

8961-429: The omentum. In order to determine if there are metastases, surgeons will inspect the abdomen at the beginning of the procedure after gaining access. Alternatively, they may perform a separate procedure called a diagnostic laparoscopy which involves insertion of a small camera through a small incision to look inside the abdomen. This may spare the patient the large abdominal incision that would occur if they were to undergo

9064-422: The pancreas , cancer metastatic to the pancreas, multiple endocrine neoplasia type 1 and gastrointestinal stromal tumors . Pancreaticoduodenectomy is the only potentially curative intervention for malignant tumors of the pancreas . However, the majority of patients with pancreatic cancer present with metastatic or locally advanced un-resectable disease; thus only 15–20% of patients are candidates for

9167-460: The pancreas and duodenum, damage to the common bile duct, pancreatic leakage, or transection of the duodenum. Due to the rarity of this procedure in the setting of trauma, there is not robust evidence regarding post-operative outcomes. In order to be considered for surgical removal, the tumor cannot encase more than 50% of any of the following vessels: the celiac artery, superior mesenteric artery, or inferior vena cava. In cases where less than 50% of

9270-422: The pancreas were removed it would compromise blood flow to the duodenum, resulting in tissue necrosis . While the blood supply to the liver is left intact, the common bile duct is removed. This means that while the liver remains with a good blood supply the surgeon must make a new connection to drain bile produced in the liver. This is done at the end of the surgery. The surgeon will make a new attachment between

9373-404: The pancreatic duct and the jejunum or stomach. During the surgery, a cholecystectomy is performed to remove the gallbladder . This portion is not done en bloc, as the gallbladder is removed separately. Relevant nearby anatomy not removed during the procedure include the major vascular structures in the area: the portal vein , the superior mesenteric vein , and the superior mesenteric artery ,

9476-484: The pylorus-preserving pancreaticoduodenectomy (also known as Traverso–Longmire procedure/PPPD) has been gaining popularity, especially among European surgeons. The main advantage of this technique is that the pylorus , and thus normal gastric emptying, should in theory be preserved. There is conflicting data as to whether pylorus-preserving pancreaticoduodenectomy is associated with increased likelihood of gastric emptying. In practice, it shows similar long-term survival as

9579-586: The raised but relatively flat plateau of the Canadian Shield in the northeast; and the varied eastern region, which includes the Appalachian Mountains, the coastal plain along the Atlantic seaboard, and the Florida peninsula. Mexico, with its long plateaus and cordilleras , falls largely in the western region, although the eastern coastal plain does extend south along the Gulf. The western mountains are split in

9682-500: The region, and as such rainforest , monsoon , and savanna types can be found, with rains and high temperatures throughout the year. Notable North American fauna include the bison , black bear , jaguar , cougar , prairie dog , turkey , pronghorn , raccoon , coyote , and monarch butterfly . Notable plants that were domesticated in North America include tobacco , maize , squash , tomato , sunflower , blueberry , avocado , cotton , chile pepper , and vanilla . Laurentia

9785-478: The results of the formation of Pangaea was the Appalachian Mountains , which formed some 480 mya, making it among the oldest mountain ranges in the world. When Pangaea began to rift around 200 mya, North America became part of Laurasia , before it separated from Eurasia as its own continent during the mid- Cretaceous period. The Rockies and other western mountain ranges began forming around this time from

9888-548: The thyroid and parathyroid glands in the neck and the adrenal glands just above each kidney in the abdomen. In many communities, they are the only surgeon trained to do this. In communities that have a number of subspecialists, other subspecialty surgeons may assume responsibility for these procedures. Responsible for all aspects of pre-operative, operative, and post-operative care of abdominal organ transplant patients. Transplanted organs include liver, kidney, pancreas, and more rarely small bowel. Surgical oncologist refers to

9991-737: The two methods. Pancreaticoduodenectomy is considered, by any standard, to be a major surgical procedure. Many studies have shown that hospitals where a given operation is performed more frequently have better overall results (especially in the case of more complex procedures, such as pancreaticoduodenectomy). A frequently cited study published in The New England Journal of Medicine found operative mortality rates to be four times higher (16.3 v. 3.8%) at low-volume (averaging less than one pancreaticoduodenectomy per year) hospitals than at high-volume (16 or more per year) hospitals. Even at high-volume hospitals, morbidity has been found to vary by

10094-400: The upper limit of normal, occurs in 5–10% of operations, although changes in the definition of fistula may now include a much larger proportion of patients (upwards of 40%). Immediately after surgery, patients are monitored for return of bowel function and appropriate closed-suction drainage of the abdomen. Ileus , which refers to functional obstruction or aperistalsis of the intestine,

10197-407: The vessel is involved, vascular surgeons remove the involved portion of the vessel, and repair the residual artery or vein. Tumors are still borderline resectable even if they involve the superior mesenteric or portal veins, gastroduodenal artery, superior mesenteric vein or colon. Metastatic disease is another contradiction to surgery. It most often occurs in the peritoneum, in the liver, and in

10300-540: Was called the Council of the Indies . The United Nations and its statistics division recognize North America as including three regions: Northern America, Central America , and the Caribbean . "Northern America" is a distinct term from "North America", excluding Central America, which itself may or may not include Mexico . In the limited context of regional trade agreements, the term is used to reference three nations: Canada,

10403-790: Was in Jamestown, Virginia in 1607, followed by additional colonial establishments on the east coast from present-day Georgia in the south to Massachusetts in the north, forming the Thirteen Colonies of British America. The English did not establish settlements north or east of the St. Lawrence Valley in present-day Canada until after the conclusion of the American Revolutionary War . Britain's early settlements in present-day Canada included St. John's, Newfoundland in 1630 and Halifax, Nova Scotia in 1749. The first permanent French settlement

10506-505: Was in Quebec City, Quebec in 1608 Pancreaticoduodenectomy A pancreaticoduodenectomy , also known as a Whipple procedure , is a major surgical operation most often performed to remove cancerous tumours from the head of the pancreas . It is also used for the treatment of pancreatic or duodenal trauma, or chronic pancreatitis . Due to the shared blood supply of organs in the proximal gastrointestinal system, surgical removal of

10609-468: Was the first European to suggest that the Americas represented a landmass not then known to the Europeans. In 1507, Waldseemüller published a world map, and placed the word "America" on the continent of present-day South America. The continent north of present-day Mexico was then referred to as Parias. On a 1553 world map published by Petrus Apianus , North America was called "Baccalearum", meaning "realm of

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