87-565: A camel is a hoofed mammal. Camel or Camels may also refer to: Camel A camel (from Latin : camelus and ‹See Tfd› Greek : κάμηλος ( kamēlos ) from Ancient Semitic : gāmāl ) is an even-toed ungulate in the genus Camelus that bears distinctive fatty deposits known as "humps" on its back. Camels have long been domesticated and, as livestock , they provide food ( camel milk and meat) and textiles (fiber and felt from camel hair ). Camels are working animals especially suited to their desert habitat and are
174-555: A blood bank for blood transfusion . The vast majority of vertebrates, including mammals and humans, have red blood cells. Red blood cells are cells present in blood to transport oxygen. The only known vertebrates without red blood cells are the crocodile icefish (family Channichthyidae ); they live in very oxygen-rich cold water and transport oxygen freely dissolved in their blood. While they no longer use hemoglobin, remnants of hemoglobin genes can be found in their genome . Vertebrate red blood cells consist mainly of hemoglobin ,
261-455: A cell nucleus . In comparison, the red blood cells of other vertebrates have nuclei; the only known exceptions are salamanders of the family Plethodontidae , where five different clades has evolved various degrees of enucleated red blood cells (most evolved in some species of the genus Batrachoseps ), and fish of the genus Maurolicus . The elimination of the nucleus in vertebrate red blood cells has been offered as an explanation for
348-423: A dulla in his throat, a large, inflatable sac that he extrudes from his mouth when in rut to assert dominance and attract females. It resembles a long, swollen, pink tongue hanging out of the side of the camel's mouth. Camels mate by having both male and female sitting on the ground, with the male mounting from behind. The male usually ejaculates three or four times within a single mating session. Camelids are
435-691: A torus -shaped rim on the edge of the disk. This shape allows for a high surface-area-to-volume (SA/V) ratio to facilitate diffusion of gases. However, there are some exceptions concerning shape in the artiodactyl order (even-toed ungulates including cattle, deer, and their relatives), which displays a wide variety of bizarre red blood cell morphologies: small and highly ovaloid cells in llamas and camels (family Camelidae ), tiny spherical cells in mouse deer (family Tragulidae ), and cells which assume fusiform, lanceolate, crescentic, and irregularly polygonal and other angular forms in red deer and wapiti (family Cervidae ). Members of this order have clearly evolved
522-412: A barrier against sand. If sand gets lodged in their eyes, they can dislodge it using their translucent third eyelid (also known as the nictitating membrane). The camels' gait and widened feet help them move without sinking into the sand. The kidneys and intestines of a camel are very efficient at reabsorbing water. Camels' kidneys have a 1:4 cortex to medulla ratio . Thus, the medullary part of
609-502: A camel's kidney occupies twice as much area as a cow's kidney. Secondly, renal corpuscles have a smaller diameter, which reduces surface area for filtration. These two major anatomical characteristics enable camels to conserve water and limit the volume of urine in extreme desert conditions. Camel urine comes out as a thick syrup, and camel faeces are so dry that they do not require drying when used to fuel fires. The camel immune system differs from those of other mammals. Normally,
696-420: A complex metalloprotein containing heme groups whose iron atoms temporarily bind to oxygen molecules (O 2 ) in the lungs or gills and release them throughout the body. Oxygen can easily diffuse through the red blood cell's cell membrane . Hemoglobin in the red blood cells also carries some of the waste product carbon dioxide back from the tissues; most waste carbon dioxide, however, is transported back to
783-579: A few hundred up to a million copies per red blood cell. Approximately 25 of these membrane proteins carry the various blood group antigens, such as the A, B and Rh antigens, among many others. These membrane proteins can perform a wide diversity of functions, such as transporting ions and molecules across the red cell membrane, adhesion and interaction with other cells such as endothelial cells, as signaling receptors, as well as other currently unknown functions. The blood types of humans are due to variations in surface glycoproteins of red blood cells. Disorders of
870-403: A foot taller. Camels can run at up to 65 km/h (40 mph) in short bursts and sustain speeds of up to 40 km/h (25 mph). Bactrian camels weigh 300 to 1,000 kg (660 to 2,200 lb) and dromedaries 300 to 600 kg (660 to 1,320 lb). The widening toes on a camel's hoof provide supplemental grip for varying soil sediments. The male dromedary camel has an organ called
957-604: A key role in the CO 2 transport process, for two reasons. First, because, besides hemoglobin, they contain a large number of copies of the enzyme carbonic anhydrase on the inside of their cell membrane. Carbonic anhydrase, as its name suggests, acts as a catalyst of the exchange between carbonic acid and carbon dioxide (which is the anhydride of carbonic acid). Because it is a catalyst, it can affect many CO 2 molecules, so it performs its essential role without needing as many copies as are needed for O 2 transport by hemoglobin. In
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#17327719151861044-660: A minimum thickness in the centre of 0.8–1 μm, being much smaller than most other human cells . These cells have an average volume of about 90 fL with a surface area of about 136 μm , and can swell up to a sphere shape containing 150 fL, without membrane distension. Adult humans have roughly 20–30 trillion red blood cells at any given time, constituting approximately 70% of all cells by number. Women have about 4–5 million red blood cells per microliter (cubic millimeter) of blood and men about 5–6 million; people living at high altitudes with low oxygen tension will have more. Red blood cells are thus much more common than
1131-467: A mixture of wool and camel hair was used. By at least 1200 BC the first camel saddles had appeared, and Bactrian camels could be ridden. The first saddle was positioned to the back of the camel, and control of the Bactrian camel was exercised by means of a stick. However, between 500 and 100 BC, Bactrian camels came into military use. New saddles, which were inflexible and bent, were put over
1218-795: A mode of red blood cell development substantially different from the mammalian norm. Overall, mammalian red blood cells are remarkably flexible and deformable so as to squeeze through tiny capillaries , as well as to maximize their apposing surface by assuming a cigar shape, where they efficiently release their oxygen load. Red blood cells in mammals are unique amongst vertebrates as they do not have nuclei when mature. They do have nuclei during early phases of erythropoiesis , but extrude them during development as they mature; this provides more space for hemoglobin. The red blood cells without nuclei, called reticulocytes , subsequently lose all other cellular organelles such as their mitochondria , Golgi apparatus and endoplasmic reticulum . The spleen acts as
1305-471: A pH buffer. In summary, carbon dioxide produced by cellular respiration diffuses very rapidly to areas of lower concentration, specifically into nearby capillaries. When it diffuses into a RBC, CO 2 is rapidly converted by the carbonic anhydrase found on the inside of the RBC membrane into bicarbonate ion. The bicarbonate ions in turn leave the RBC in exchange for chloride ions from the plasma, facilitated by
1392-446: A pan- Trypanozoon test, which would also be useful for T. b. brucei , T. b. gambiense , T. b. rhodesiense , and T. equiperdum . The karyotypes of different camelid species have been studied earlier by many groups, but no agreement on chromosome nomenclature of camelids has been reached. A 2007 study flow sorted camel chromosomes, building on the fact that camels have 37 pairs of chromosomes (2n=74), and found that
1479-420: A reservoir of red blood cells, but this effect is somewhat limited in humans. In some other mammals such as dogs and horses, the spleen sequesters large numbers of red blood cells, which are dumped into the blood during times of exertion stress, yielding a higher oxygen transport capacity. A typical human red blood cell has a disk diameter of approximately 6.2–8.2 μm and a maximum thickness of 2–2.5 μm and
1566-463: A result of not containing mitochondria , red blood cells use none of the oxygen they transport; instead they produce the energy carrier ATP by the glycolysis of glucose and lactic acid fermentation on the resulting pyruvate . Furthermore, the pentose phosphate pathway plays an important role in red blood cells; see glucose-6-phosphate dehydrogenase deficiency for more information. As red blood cells contain no nucleus, protein biosynthesis
1653-421: A signalling gas that acts to relax vessel walls. It is believed that the cardioprotective effects of garlic are due to red blood cells converting its sulfur compounds into hydrogen sulfide. Red blood cells also play a part in the body's immune response : when lysed by pathogens such as bacteria, their hemoglobin releases free radicals , which break down the pathogen's cell wall and membrane, killing it. As
1740-429: A third of the total cell volume. Hemoglobin is responsible for the transport of more than 98% of the oxygen in the body (the remaining oxygen is carried dissolved in the blood plasma ). The red blood cells of an average adult human male store collectively about 2.5 grams of iron, representing about 65% of the total iron contained in the body. Red blood cells in mammals are anucleate when mature, meaning that they lack
1827-866: A thousand more camels), the outbreak of the American Civil War in 1861 saw the end of the Camel Corps: Texas became part of the Confederacy, and most of the camels were left to wander away into the desert. France created a méhariste camel corps in 1912 as part of the Armée d'Afrique in the Sahara in order to exercise greater control over the camel-riding Tuareg and Arab insurgents, as previous efforts to defeat them on foot had failed. The Free French Camel Corps fought during World War II , and camel-mounted units remained in service until
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#17327719151861914-412: A typical lipid bilayer , similar to what can be found in virtually all human cells. Simply put, this lipid bilayer is composed of cholesterol and phospholipids in equal proportions by weight. The lipid composition is important as it defines many physical properties such as membrane permeability and fluidity. Additionally, the activity of many membrane proteins is regulated by interactions with lipids in
2001-411: A vital means of transport for passengers and cargo. There are three surviving species of camel. The one-humped dromedary makes up 94% of the world's camel population, and the two-humped Bactrian camel makes up 6%. The wild Bactrian camel is a distinct species that is not ancestral to the domestic Bactrian camel, and is now critically endangered , with fewer than 1,000 individuals. The word camel
2088-399: Is a camel-llama hybrid bred by scientists to see how closely related the parent species are. Scientists collected semen from a camel via an artificial vagina and inseminated a llama after stimulating ovulation with gonadotrophin injections. The cama is halfway in size between a camel and a llama and lacks a hump. It has ears intermediate between those of camels and llamas, longer legs than
2175-430: Is a net decrease in water. Camels have a series of physiological adaptations that allow them to withstand long periods of time without any external source of water. The dromedary camel can drink as seldom as once every 10 days even under very hot conditions, and can lose up to 30% of its body mass due to dehydration. Unlike other mammals, camels' red blood cells are oval rather than circular in shape. This facilitates
2262-461: Is a very bright red in color. Flushed, confused patients with a saturation reading of 100% on pulse oximetry are sometimes found to be suffering from carbon monoxide poisoning. Having oxygen-carrying proteins inside specialized cells (as opposed to oxygen carriers being dissolved in body fluid) was an important step in the evolution of vertebrates as it allows for less viscous blood, higher concentrations of oxygen, and better diffusion of oxygen from
2349-568: Is also used informally in a wider sense, where the more correct term is "camelid", to include all seven species of the family Camelidae : the true camels (the above three species), along with the "New World" camelids: the llama , the alpaca , the guanaco , and the vicuña , which belong to the separate tribe Lamini . Camelids originated in North America during the Eocene , with the ancestor of modern camels, Paracamelus , migrating across
2436-641: Is currently assumed to be absent in these cells. Because of the lack of nuclei and organelles, mature red blood cells do not contain DNA and cannot synthesize any RNA (although it does contain RNAs), and consequently cannot divide and have limited repair capabilities. The inability to carry out protein synthesis means that no virus can evolve to target mammalian red blood cells. However, infection with parvoviruses (such as human parvovirus B19 ) can affect erythroid precursors while they still have DNA, as recognized by
2523-504: Is estimated to have stood around nine feet (2.7 metres) tall. The Bactrian camel diverged from the dromedary about 1 million years ago, according to the fossil record. The last camel native to North America was Camelops hesternus , which vanished along with horses , short-faced bears , mammoths and mastodons , ground sloths , sabertooth cats , and many other megafauna as part of the Quaternary extinction event , coinciding with
2610-963: Is held in Saudi Arabia. In addition to camel racing and camel milk tasting, the festival holds a camel " beauty pageant " with prize money of $ 57m (£40m). In 2018, 12 camels were disqualified from the beauty contest after their owners were found to have injected them with botox . In a similar incident in 2021, over 40 camels were disqualified. Camel meat and milk are foods that are found in many cuisines, typically in Middle Eastern , North African and some Australian cuisines . Red blood cell Red blood cells ( RBCs ), referred to as erythrocytes (from Ancient Greek erythros 'red' and kytos 'hollow vessel', with - cyte translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells , erythroid cells , and rarely haematids , are
2697-520: Is reabsorbed into the body as a means to conserve water. Camels eating green herbage can ingest sufficient moisture in milder conditions to maintain their bodies' hydrated state without the need for drinking. The camel's thick coat insulates it from the intense heat radiated from desert sand; a shorn camel must sweat 50% more to avoid overheating. During the summer the coat becomes lighter in color, reflecting light as well as helping avoid sunburn. The camel's long legs help by keeping its body farther from
Camel (disambiguation) - Misplaced Pages Continue
2784-407: Is responsible for the red color of the cells and the blood. Each human red blood cell contains approximately 270 million hemoglobin molecules. The cell membrane is composed of proteins and lipids , and this structure provides properties essential for physiological cell function such as deformability and stability of the blood cell while traversing the circulatory system and specifically
2871-407: Is −15.7 milli volts (mV). Much of this potential appears to be contributed by the exposed sialic acid residues in the membrane: their removal results in zeta potential of −6.06 mV. Recall that respiration , as illustrated schematically here with a unit of carbohydrate, produces about as many molecules of carbon dioxide, CO 2 , as it consumes of oxygen, O 2 . Thus, the function of
2958-879: The Achaemenid Persians when fighting Lydia in the Battle of Thymbra (547 BC). The United States Army established the U.S. Camel Corps , stationed in California , in the 19th century. One may still see stables at the Benicia Arsenal in Benicia, California , where they nowadays serve as the Benicia Historical Museum. Though the experimental use of camels was seen as a success ( John B. Floyd , Secretary of War in 1858, recommended that funds be allocated towards obtaining
3045-532: The Arabian Peninsula , dating to around 930 BC. This garnered considerable media coverage, as it is strong evidence that the stories of Abraham , Jacob , Esau , and Joseph were written after this time . The existence of camels in Mesopotamia—but not in the eastern Mediterranean lands—is not a new idea. The historian Richard Bulliet did not think that the occasional mention of camels in
3132-465: The Aravah Valley enable us to pinpoint the introduction of domestic camels to the southern Levant more precisely based on stratigraphic contexts associated with an extensive suite of radiocarbon dates . The data indicate that this event occurred not earlier than the last third of the 10th century [BC] and most probably during this time. The coincidence of this event with a major reorganization of
3219-469: The Battle of Qarqar in 853 BC. Armies have also used camels as freight animals instead of horses and mules. The East Roman Empire used auxiliary forces known as dromedarii , whom the Romans recruited in desert provinces. The camels were used mostly in combat because of their ability to scare off horses at close range (horses are afraid of the camels' scent), a quality famously employed by
3306-465: The Bering land bridge into Asia during the late Miocene , around 6 million years ago. Three species are extant : [REDACTED] [REDACTED] [REDACTED] The average life expectancy of a camel is 40 to 50 years. A full-grown adult dromedary camel stands 1.85 m (6 ft 1 in) at the shoulder and 2.15 m (7 ft 1 in) at the hump. Bactrian camels can be
3393-812: The British Indian Army in World Wars I and II. The Tropas Nómadas (Nomad Troops) were an auxiliary regiment of Sahrawi tribesmen serving in the colonial army in Spanish Sahara (today Western Sahara ). Operational from the 1930s until the end of the Spanish presence in the territory in 1975, the Tropas Nómadas were equipped with small arms and led by Spanish officers. The unit guarded outposts and sometimes conducted patrols on camelback. The annual King Abdulaziz Camel Festival
3480-655: The Gobi Desert . When humans first domesticated camels is disputed. Dromedaries may have first been domesticated by humans in Somalia or South Arabia sometime during the 3rd millennium BC , the Bactrian in central Asia around 2,500 BC, as at Shar-i Sokhta (also known as the Burnt City), Iran . A study from 2016, which genotyped and used world-wide sequencing of modern and ancient mitochondrial DNA (mtDNA), suggested that they were initially domesticated in
3567-441: The band 3 anion transport protein colocated in the RBC membrane. The bicarbonate ion does not diffuse back out of the capillary, but is carried to the lung. In the lung the lower partial pressure of carbon dioxide in the alveoli causes carbon dioxide to diffuse rapidly from the capillary into the alveoli. The carbonic anhydrase in the red cells keeps the bicarbonate ion in equilibrium with carbon dioxide. So as carbon dioxide leaves
Camel (disambiguation) - Misplaced Pages Continue
3654-440: The bone marrow and circulate for about 100–120 days in the body before their components are recycled by macrophages . Each circulation takes about 60 seconds (one minute). Approximately 84% of the cells in the human body are the 20–30 trillion red blood cells. Nearly half of the blood's volume ( 40% to 45% ) is red blood cells. Packed red blood cells are red blood cells that have been donated, processed, and stored in
3741-415: The capillary network. In humans, mature red blood cells are flexible biconcave disks . They lack a cell nucleus (which is expelled during development ) and organelles , to accommodate maximum space for hemoglobin; they can be viewed as sacks of hemoglobin, with a plasma membrane as the sack. Approximately 2.4 million new erythrocytes are produced per second in human adults. The cells develop in
3828-411: The pulmonary capillaries of the lungs as bicarbonate (HCO 3 ) dissolved in the blood plasma . Myoglobin , a compound related to hemoglobin, acts to store oxygen in muscle cells. The color of red blood cells is due to the heme group of hemoglobin. The blood plasma alone is straw-colored, but the red blood cells change color depending on the state of the hemoglobin: when combined with oxygen
3915-689: The Bible meant that the domestic camels were common in the Holy Land at that time. The archaeologist William F. Albright , writing even earlier, saw camels in the Bible as an anachronism . The official report by Sapir-Hen and Ben-Joseph says: The introduction of the dromedary camel (Camelus dromedarius) as a pack animal to the southern Levant ... substantially facilitated trade across the vast deserts of Arabia, promoting both economic and social change (e.g., Kohler 1984; Borowski 1998: 112–116; Jasmin 2005). This ... has generated extensive discussion regarding
4002-599: The Y-shaped antibody molecules consist of two heavy (or long) chains along the length of the Y, and two light (or short) chains at each tip of the Y. Camels, in addition to these, also have antibodies made of only two heavy chains, a trait that makes them smaller and more durable. These "heavy-chain-only" antibodies, discovered in 1993, are thought to have developed 50 million years ago, after camelids split from ruminants and pigs. Camels suffer from surra caused by Trypanosoma evansi wherever camels are domesticated in
4089-443: The bilayer. Unlike cholesterol, which is evenly distributed between the inner and outer leaflets, the 5 major phospholipids are asymmetrically disposed, as shown below: Outer monolayer Inner monolayer This asymmetric phospholipid distribution among the bilayer is the result of the function of several energy-dependent and energy-independent phospholipid transport proteins. Proteins called " Flippases " move phospholipids from
4176-433: The blood to the tissues. The size of red blood cells varies widely among vertebrate species; red blood cell width is on average about 25% larger than capillary diameter, and it has been hypothesized that this improves the oxygen transfer from red blood cells to tissues. The red blood cells of mammals are typically shaped as biconcave disks: flattened and depressed in the center, with a dumbbell -shaped cross section, and
4263-401: The body depleted of oxygen. Red blood cells can also synthesize nitric oxide enzymatically, using L-arginine as substrate, as do endothelial cells . Exposure of red blood cells to physiological levels of shear stress activates nitric oxide synthase and export of nitric oxide, which may contribute to the regulation of vascular tonus. Red blood cells can also produce hydrogen sulfide ,
4350-450: The capillary, act to reduce the oxygen binding affinity of hemoglobin, the Bohr effect . The second major contribution of RBC to carbon dioxide transport is that carbon dioxide directly reacts with globin protein components of hemoglobin to form carbaminohemoglobin compounds. As oxygen is released in the tissues, more CO 2 binds to hemoglobin, and as oxygen binds in the lung, it displaces
4437-510: The capillary, and CO 2 is displaced by O 2 on hemoglobin, sufficient bicarbonate ion converts rapidly to carbon dioxide to maintain the equilibrium. When red blood cells undergo shear stress in constricted vessels, they release ATP , which causes the vessel walls to relax and dilate so as to promote normal blood flow. When their hemoglobin molecules are deoxygenated, red blood cells release S-Nitrosothiols , which also act to dilate blood vessels, thus directing more blood to areas of
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#17327719151864524-441: The circulatory system is as much about the transport of carbon dioxide as about the transport of oxygen. As stated elsewhere in this article, most of the carbon dioxide in the blood is in the form of bicarbonate ion. The bicarbonate provides a critical pH buffer . Thus, unlike hemoglobin for O 2 transport, there is a physiological advantage to not having a specific CO 2 transporter molecule. Red blood cells, nevertheless, play
4611-413: The copper industry of the region—attributed to the results of the campaign of Pharaoh Shoshenq I —raises the possibility that the two were connected, and that camels were introduced as part of the efforts to improve efficiency by facilitating trade. Desert tribes and Mongolian nomads use camel hair for tents, yurts , clothing, bedding and accessories. Camels have outer guard hairs and soft inner down, and
4698-477: The date of the earliest domestic camel in the southern Levant (and beyond) (e.g., Albright 1949: 207; Epstein 1971: 558–584; Bulliet 1975; Zarins 1989; Köhler-Rollefson 1993; Uerpmann and Uerpmann 2002; Jasmin 2005; 2006; Heide 2010; Rosen and Saidel 2010; Grigson 2012). Most scholars today agree that the dromedary was exploited as a pack animal sometime in the early Iron Age (not before the 12th century [BC]) and concludes: Current data from copper smelting sites of
4785-807: The end of French rule over Algeria in 1962. In 1916, the British created the Imperial Camel Corps . It was originally used to fight the Senussi , but was later used in the Sinai and Palestine Campaign in World War I . The Imperial Camel Corps comprised infantrymen mounted on camels for movement across desert, though they dismounted at battle sites and fought on foot. After July 1918, the Corps began to become run down, receiving no new reinforcements, and
4872-399: The fibers may also be sorted by color and age of the animal. The guard hairs can be felted for use as waterproof coats for the herdsmen, while the softer hair is used for premium goods. The fiber can be spun for use in weaving or made into yarns for hand knitting or crochet. Pure camel hair is recorded as being used for western garments from the 17th century onwards, and from the 19th century
4959-491: The flow of red blood cells during dehydration and makes them better at withstanding high osmotic variation without rupturing when drinking large amounts of water. Camels are able to withstand changes in body temperature and water consumption that would kill most other mammals. Their temperature ranges from 34 °C (93 °F) at dawn and steadily increases to 40 °C (104 °F) by sunset, before they cool off at night again. In general, to compare between camels and
5046-463: The ground, which can heat up to 70 °C (158 °F). Dromedaries have a pad of thick tissue over the sternum called the pedestal . When the animal lies down in a sternal recumbent position, the pedestal raises the body from the hot surface and allows cooling air to pass under the body. Camels' mouths have a thick leathery lining, allowing them to chew thorny desert plants. Long eyelashes and ear hairs, together with nostrils that can close, form
5133-487: The hemoglobin bound CO 2 , this is called the Haldane effect . Despite the fact that only a small amount of the CO 2 in blood is bound to hemoglobin in venous blood, a greater proportion of the change in CO 2 content between venous and arterial blood comes from the change in this bound CO 2 . That is, there is always an abundance of bicarbonate in blood, both venous and arterial, because of its aforementioned role as
5220-546: The humps and divided the rider's weight over the animal. In the seventh century BC the military Arabian saddle evolved, which again improved the saddle design slightly. Military forces have used camel cavalries in wars throughout Africa, the Middle East, and their use continues into the modern-day within the Border Security Force (BSF) of India . The first documented use of camel cavalries occurred in
5307-428: The karyotype consisted of one metacentric , three submetacentric, and 32 acrocentric autosomes. The Y is a small metacentric chromosome, while the X is a large metacentric chromosome. The hybrid camel , a hybrid between Bactrian and dromedary camels, has one hump, though it has an indentation 4–12 cm (1.6–4.7 in) deep that divides the front from the back. The hybrid is 2.15 m (7 ft 1 in) at
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#17327719151865394-793: The late Miocene, between 7.5 and 6.5 million years ago. During the Pleistocene, around 3 to 1 million years ago, the North American Camelidae spread to South America as part of the Great American Interchange via the newly formed Isthmus of Panama , where they gave rise to guanacos and related animals. Populations of Paracamelus continued to exist in the North American Arctic into the Early Pleistocene . This creature
5481-415: The lipid bilayer and membrane skeleton, likely enabling the red cell to maintain its favorable membrane surface area by preventing the membrane from collapsing (vesiculating). The zeta potential is an electrochemical property of cell surfaces that is determined by the net electrical charge of molecules exposed at the surface of cell membranes of the cell. The normal zeta potential of the red blood cell
5568-470: The llama, and partially cloven hooves . Like the mule , camas are sterile, despite both parents having the same number of chromosomes. The earliest known camel, called Protylopus , lived in North America 40 to 50 million years ago (during the Eocene ). It was about the size of a rabbit and lived in the open woodlands of what is now South Dakota . By 35 million years ago, the Poebrotherium
5655-557: The membrane composition. The red blood cell membrane is composed of 3 layers: the glycocalyx on the exterior, which is rich in carbohydrates ; the lipid bilayer which contains many transmembrane proteins , besides its lipidic main constituents; and the membrane skeleton, a structural network of proteins located on the inner surface of the lipid bilayer. Half of the membrane mass in human and most mammalian red blood cells are proteins. The other half are lipids, namely phospholipids and cholesterol . The red blood cell membrane comprises
5742-432: The membrane skeleton are responsible for the deformability, flexibility and durability of the red blood cell, enabling it to squeeze through capillaries less than half the diameter of the red blood cell (7–8 μm) and recovering the discoid shape as soon as these cells stop receiving compressive forces, in a similar fashion to an object made of rubber. There are currently more than 50 known membrane proteins, which can exist in
5829-614: The migration of humans from Asia at the end of the Pleistocene, around 13–11,000 years ago. An extinct giant camel species, Camelus knoblochi roamed Asia during the Late Pleistocene, before becoming extinct around 20,000 years ago. Like horses , camels originated in North America and eventually spread across Beringia to Asia. They survived in the Old World, and eventually humans domesticated them and spread them globally. Along with many other megafauna in North America,
5916-456: The most common type of blood cell and the vertebrate 's principal means of delivering oxygen ( O 2 ) to the body tissues —via blood flow through the circulatory system . Erythrocytes take up oxygen in the lungs , or in fish the gills , and release it into tissues while squeezing through the body's capillaries . The cytoplasm of a red blood cell is rich in hemoglobin (Hb), an iron -containing biomolecule that can bind oxygen and
6003-421: The only ungulates to mate in a sitting position. Camels do not directly store water in their humps; they are reservoirs of fatty tissue. When this tissue is metabolized, it yields a greater mass of water than that of the fat processed. This fat metabolization , while releasing energy, causes water to evaporate from the lungs during respiration (as oxygen is required for the metabolic process): overall, there
6090-547: The original wild camels were wiped out during the spread of the first indigenous peoples of the Americas from Asia into North America, 10 to 12,000 years ago; although fossils have never been associated with definitive evidence of hunting. Most camels surviving today are domesticated. Although feral populations exist in Australia , India and Kazakhstan, wild camels survive only in the wild Bactrian camel population of
6177-403: The other blood particles: there are about 4,000–11,000 white blood cells and about 150,000–400,000 platelets per microliter. Human red blood cells take on average 60 seconds to complete one cycle of circulation. The blood's red color is due to the spectral properties of the hemic iron ions in hemoglobin . Each hemoglobin molecule carries four heme groups; hemoglobin constitutes about
6264-525: The other livestock, camels lose only 1.3 liters of fluid intake every day while the other livestock lose 20 to 40 liters per day. Maintaining the brain temperature within certain limits is critical for animals; to assist this, camels have a rete mirabile , a complex of arteries and veins lying very close to each other which utilizes countercurrent blood flow to cool blood flowing to the brain. Camels rarely sweat, even when ambient temperatures reach 49 °C (120 °F). Any sweat that does occur evaporates at
6351-448: The outer to the inner monolayer, while others called " floppases " do the opposite operation, against a concentration gradient in an energy-dependent manner. Additionally, there are also " scramblase " proteins that move phospholipids in both directions at the same time, down their concentration gradients in an energy-independent manner. There is still considerable debate ongoing regarding the identity of these membrane maintenance proteins in
6438-542: The patriarchal narratives may refer, at least in some places, to the Bactrian camel", while noting that the camel is not mentioned in relationship to Canaan . Heide and Joris Peters reasserted that conclusion in their 2021 study on the subject. In 2009–2013, excavations in the Timna Valley by Lidar Sapir-Hen and Erez Ben-Yosef discovered what may be the earliest domestic camel bones yet found in Israel or even outside
6525-445: The presence of giant pronormoblasts with viral particles and inclusion bodies , thus temporarily depleting the blood of reticulocytes and causing anemia . Human red blood cells are produced through a process named erythropoiesis , developing from committed stem cells to mature red blood cells in about 7 days. When matured, in a healthy individual these cells live in blood circulation for about 100 to 120 days (and 80 to 90 days in
6612-440: The presence of this catalyst carbon dioxide and carbonic acid reach an equilibrium very rapidly, while the red cells are still moving through the capillary. Thus it is the RBC that ensures that most of the CO 2 is transported as bicarbonate. At physiological pH the equilibrium strongly favors carbonic acid, which is mostly dissociated into bicarbonate ion. The H+ ions released by this rapid reaction within RBC, while still in
6699-474: The proteins in these membranes are associated with many disorders, such as hereditary spherocytosis , hereditary elliptocytosis , hereditary stomatocytosis , and paroxysmal nocturnal hemoglobinuria . The red blood cell membrane proteins organized according to their function: Transport Cell adhesion Structural role – The following membrane proteins establish linkages with skeletal proteins and may play an important role in regulating cohesion between
6786-862: The red cell membrane. The maintenance of an asymmetric phospholipid distribution in the bilayer (such as an exclusive localization of PS and PIs in the inner monolayer) is critical for the cell integrity and function due to several reasons: The presence of specialized structures named " lipid rafts " in the red blood cell membrane have been described by recent studies. These are structures enriched in cholesterol and sphingolipids associated with specific membrane proteins, namely flotillins , STOMatins (band 7), G-proteins , and β-adrenergic receptors . Lipid rafts that have been implicated in cell signaling events in nonerythroid cells have been shown in erythroid cells to mediate β2-adregenic receptor signaling and increase cAMP levels, and thus regulating entry of malarial parasites into normal red cells. The proteins of
6873-468: The resulting oxyhemoglobin is scarlet, and when oxygen has been released the resulting deoxyhemoglobin is of a dark red burgundy color. However, blood can appear bluish when seen through the vessel wall and skin. Pulse oximetry takes advantage of the hemoglobin color change to directly measure the arterial blood oxygen saturation using colorimetric techniques. Hemoglobin also has a very high affinity for carbon monoxide , forming carboxyhemoglobin which
6960-556: The shoulder and 2.32 m (7 ft 7 in) tall at the hump. It weighs an average of 650 kg (1,430 lb) and can carry around 400 to 450 kg (880 to 990 lb), which is more than either the dromedary or Bactrian can. According to molecular data, the wild Bactrian camel ( C. ferus ) separated from the domestic Bactrian camel ( C. bactrianus ) about 1 million years ago. New World and Old World camelids diverged about 11 million years ago. In spite of this, these species can hybridize and produce viable offspring. The cama
7047-418: The skin level rather than at the surface of their coat; the heat of vaporization therefore comes from body heat rather than ambient heat. Camels can withstand losing 25% of their body weight in water, whereas most other mammals can withstand only about 12–14% dehydration before cardiac failure results from circulatory disturbance. When the camel exhales, water vapor becomes trapped in their nostrils and
7134-532: The southeast Arabian Peninsula, with the Bactrian type later being domesticated around Central Asia. Martin Heide's 2010 work on the domestication of the camel tentatively concludes that humans had domesticated the Bactrian camel by at least the middle of the third millennium somewhere east of the Zagros Mountains , with the practice then moving into Mesopotamia. Heide suggests that mentions of camels "in
7221-827: The subsequent accumulation of non-coding DNA in the genome . The argument runs as follows: Efficient gas transport requires red blood cells to pass through very narrow capillaries, and this constrains their size. In the absence of nuclear elimination, the accumulation of repeat sequences is constrained by the volume occupied by the nucleus, which increases with genome size. Nucleated red blood cells in mammals consist of two forms: normoblasts, which are normal erythropoietic precursors to mature red blood cells, and megaloblasts, which are abnormally large precursors that occur in megaloblastic anemias . Red blood cells are deformable, flexible, are able to adhere to other cells, and are able to interface with immune cells. Their membrane plays many roles in this. These functions are highly dependent on
7308-664: The world, and resultantly camels have evolved trypanolytic antibodies as with many mammals. In the future, nanobody/ single-domain antibody therapy will surpass natural camel antibodies by reaching locations currently unreachable due to natural antibodies' larger size. Such therapies may also be suitable for other mammals. Tran et al. 2009 provides a new reference test for surra ( T. evansi ) of camel. They use recombinant Invariant Surface Glycoprotein 75 (rISG75, an Invariant Surface Glycoprotein ) and ELISA . The Tran test has high test specificity and appears likely to work just as well for T. evansi in other hosts, and for
7395-579: Was disbanded in 1944. Bactrian camels were used by Romanian forces during World War II in the Caucasian region. At the same period the Soviet units operating around Astrakhan in 1942 adopted local camels as draft animals due to shortage of trucks and horses, and kept them even after moving out of the area. Despite severe losses, some of these camels ended up as far west as to Berlin itself . The Bikaner Camel Corps of British India fought alongside
7482-624: Was formally disbanded in 1919. In World War I, the British Army also created the Egyptian Camel Transport Corps , which consisted of a group of Egyptian camel drivers and their camels. The Corps supported British war operations in Sinai , Palestine, and Syria by transporting supplies to the troops. The Somaliland Camel Corps was created by colonial authorities in British Somaliland in 1912; it
7569-602: Was the size of a goat and had many more traits similar to camels and llamas. The hoofed Stenomylus , which walked on the tips of its toes, also existed around this time, and the long-necked Aepycamelus evolved in the Miocene . The split between the tribes Camelini , which contains modern camels and Lamini , modern llamas , alpacas , vicuñas , and guanacos , is estimated to have occurred over 16 million years ago. The ancestor of modern camels, Paracamelus , migrated into Eurasia from North America via Beringia during
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