Why is blood red?

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Jose	its actually blue. it turns red once it takes in oxygen. Was this answer helpful to you? Yes / No

jerrod	Blood is red because of the Hemoglobin- the protien in blood that carries oxygen(O2)- the protien is built around a molecule of Iorn and when the Hemoglobin binds O2 the blood turns a bright red color. Inside your body however the blood can also be dark red in color... when not bound to O2. the generic answer is iorn because it is at the center of hemoglobin and the difference between oxidized and non oxodized hemoglobin molecules. Was this answer helpful to you? Yes / No

michiedem	oxygen in the blood makes it red Was this answer helpful to you? Yes / No

jays_mom	I don't know how true it is but when I was little I was told blood was blue inside the body, and when it came to the surface it turned red due to oxygen Was this answer helpful to you? Yes / No

Ananias's Wifey	Blood is blue till it hits oxygen then it turn red the color of blood is Essentially, rust is what makes your blood cells red. ... The blue color comes from looking at your deoxygenated blood through layers and layers of skin Was this answer helpful to you? Yes / No

holykrikey	Blood is a highly specialized circulating tissue consisting of several types of cells suspended in a fluid medium known as plasma. The cellular constituents are: red blood cells (erythrocytes), which carry respiratory gases and give it its red color because they contain hemoglobin (an iron-containing protein that binds oxygen in the lungs and transports it to tissues in the body), white blood cells (leukocytes), which fight disease, and platelets (thrombocytes), cell fragments which play an important part in the clotting of the blood. Medical terms related to blood often begin with hemo- or hemato- (BE: haemo- and haemato-) from the Greek word "haima" for "blood." Anatomically, blood is considered a connective tissue from both its origin in the bones and its function. Functions Supply of oxygen to tissues (bound to hemoglobin which is carried in red cells) Supply of nutrients such as glucose, amino acids and fatty acids (dissolved in the blood or bound to plasma proteins) Removal of waste such as carbon dioxide, Urea and lactic acid Immunological functions, including circulation of white cells, and detection of foreign material by antibodies Coagulation, which is one part of the body's self-repair mechanism Messenger functions, including the transport of hormones and the signalling of tissue damage Regulation of body pH Regulation of core body temperature Hydraulic functions Problems with blood composition or circulation can lead to downstream tissue dysfunction. The term ischaemia refers to tissue which is inadequately perfused with blood. The blood is circulated around the lungs and body by the pumping action of the heart. Additional return pressure may be generated by gravity and the actions of skeletal muscles. In mammals, blood is in equilibrium with lymph, which is continuously formed from blood (by capillary ultrafiltration) and returned to the blood (via the thoracic duct). The lymphatic circulation may be thought of as the "second circulation". Anatomy of mammalian blood Blood is composed of several kinds of cells (occasionally called corpuscles); these formed elements of the blood constitute about 45% of whole blood by volume, mostly red blood cells. The other 55% is blood plasma, a fluid that is the blood's liquid medium, appearing yellow in color. The proportion of blood occupied by red blood cells is referred to as the hematocrit. A scanning electron microscope (SEM) image of normal circulating human blood. One can see red blood cells, several white blood cells including knobby lymphocytes, a monocyte, a neutrophil, and many small disc-shaped platelets.The normal pH of human arterial blood is approximately 7.40 (normal range is 7.35-7.45), a weak alkaline solution. Blood that has a pH below 7.35 is considered overly acidic, while blood pH above 7.45 is too alkaline. Blood pH along with arterial carbon dioxide tension (PaCO2) and HCO3 readings are helpful in determining the acid-base balance of the body. The respiratory system and urinary system normally control the acid-base balance of blood as part of homeostasis. Blood is about 7% of the human body weight,[1] so the average adult has a blood volume of about 5 litres, of which 2.7-3 litres is plasma. Human blood density is around 1060 kg/m³.[2] The combined surface area of all the red cells in the human body would be roughly 2,000 times as great as the body's exterior surface.[3] The cells are: Red blood cells or erythrocytes (96%) In mammals, mature red blood cells lack a nucleus and organelles. They contain the blood's hemoglobin and distribute oxygen. The red blood cells (together with endothelial vessel cells and some other cells) are also marked by glycoproteins that define the different blood types. White blood cells or leukocytes (3.0%) White blood cells are part of the immune system; they destroy and remove old or aberrant cells and cellular debris, as well as attack infectious agents (pathogens) and foreign substances. Platelets or thrombocytes (1.0%) Platelets are responsible for blood clotting (coagulation). They change fibrinogen into fibrin. This fibrin creates a mesh onto which red blood cells collect and clot. This clot stops more blood from leaving the body and also helps to prevent bacteria from entering the body. Blood plasma is essentially an aqueous solution containing 92% water, 8% blood plasma proteins, and trace amounts of other materials. Some components are: Serum Albumin Blood clotting factors (to facilitate coagulation) Immunoglobulins (antibodies) Hormones Carbon dioxide Various other proteins Various electrolytes (mainly sodium and chloride) Together, plasma and cells form a non-Newtonian fluid whose flow properties are uniquely adapted to the architecture of the blood vessels. The term serum refers to plasma from which the clotting proteins have been removed. Most of the protein remaining is Albumin and immunoglobulins. Physiology of blood Production and degradation Blood cells are produced in the bone marrow; this process is termed hematopoiesis. The proteinaceous component (including clotting proteins) is produced overwhelmingly in the liver, while hormones are produced by the endocrine glands and the watery fraction is regulated by the hypothalamus and maintained by the kidney and indirectly by the gut. Blood cells are degraded by the spleen and the Kupffer cells in the liver. The liver also clears some proteins, lipids and amino acids. The kidney actively secretes waste products into the urine. Healthy erythrocytes have a plasma half-life of 120 days before they are systematically replaced by new erythrocytes created by the process of hematopoiesis. Transport of oxygen Further information: Oxygen transportation Blood oxygenation is measured in several ways, but the most important measure is the hemoglobin (Hb) saturation percentage. This is a non-linear (sigmoidal) function of the partial pressure of oxygen. About 98.5% of the oxygen in a sample of arterial blood in a healthy human breathing air at normal pressure is chemically combined with the Hb. Only 1.5% is physically dissolved in the other blood liquids and not connected to Hb. The hemoglobin molecule is the primary transporter of oxygen in mammals and many other species (for exceptions, see below). With the exception of pulmonary and umbilical arteries and their corresponding veins, arteries carry oxygenated blood away from the heart and deliver it to the body via arterioles and capillaries, where the oxygen is consumed; afterwards, venules and veins carry deoxygenated blood back to the heart. Differences in infrared absorption between oxygenated and deoxygenated blood form the basis for realtime oxygen saturation measurement in hospitals and ambulances. Under normal conditions in humans at rest, hemoglobin in blood leaving the lungs is about 98-99% saturated with oxygen. In a healthy adult at rest, deoxygenated blood returning to the lungs is still approximately 75% saturated.[4][5] Increased oxygen consumption during sustained exercise reduces the oxygen saturation of venous blood, which can reach less than 15% in a trained athlete; although breathing rate and blood flow increase to compensate, oxygen saturation in arterial blood can drop to 95% or less under these conditions.[6] Oxygen saturation this low is considered dangerous in an individual at rest (for instance, during surgery under anesthesia): "As a general rule, any condition which leads to a sustained mixed venous saturation of less than 50% will be poorly tolerated and a mixed venous saturation of less than 30% should be viewed as a medical emergency."[7] A fetus, receiving oxygen via the placenta, is exposed to much lower oxygen pressures (about 20% of the level found in an adult's lungs) and so fetuses produce another form of hemoglobin with a much higher affinity for oxygen (hemoglobin F) in order to extract as much oxygen as possible from this sparse supply.[8] Substances other than oxygen can bind to the hemoglobin; in some cases this can cause irreversible damage to the body. Carbon monoxide for example is extremely dangerous when absorbed into the blood. When combined with the hemoglobin, it irreversibly makes carboxyhemoglobin which reduces the volume of oxygen that can be carried in the blood. This can very quickly cause suffocation, as oxygen is vital to many organisms (including humans). This damage can occur when smoking a cigarette (or similar item) or in event of a fire. Thus carbon monoxide is considered far more dangerous than the actual fire itself because it reduces the oxygen carrying content of the blood. Insects In insects, the blood (more properly called hemolymph) is not involved in the transport of oxygen. (Openings called tracheae allow oxygen from the air to diffuse directly to the tissues). Insect blood moves nutrients to the tissues and removes waste products in an open system. Small invertebrates In some small invertebrates like insects, oxygen is simply dissolved in the plasma. Larger animals use respiratory proteins to increase the oxygen carrying capacity. Hemoglobin is the most common respiratory protein found in nature. Hemocyanin (blue) contains Copper and is found in crustaceans and mollusks. It is thought that tunicates (sea squirts) might use vanabins (proteins containing Vanadium) for respiratory pigment (bright green, blue, or orange). In many invertebrates, these oxygen-carrying proteins are freely soluble in the blood; in vertebrates they are contained in specialized red blood cells, allowing for a higher concentration of respiratory pigments without increasing viscosity or damaging blood filtering organs like the kidneys. deep Sea invertebrates Giant tube worms have extraordinary hemoglobins that allow them to live in extraordinary environments. These hemoglobins also carry sulfides normally fatal in other animals. Transport of carbon dioxide When systemic arterial blood flows through capillaries, carbon dioxide diffuses from the tissues into the blood. Some carbon dioxide is dissolved in the blood. Some carbon dioxide reacts with hemoglobin and other proteins to form carbamino compounds. The remaining carbon dioxide is converted to bicarbonate and hydrogen ions through the action of RBC carbonic anhydrase. Most carbon dioxide is transported through the blood in the form of bicarbonate ions. Transport of hydrogen ions Some oxyhemoglobin loses oxygen and becomes deoxyhemoglobin. Deoxyhemoglobin has a much greater affinity for hydrogen ion (H+) than does oxyhemoglobin so it binds most of the hydrogen ions. Thermoregulation Blood circulation transports heat through the body, and adjustments to this flow are an important part of thermoregulation. Increasing blood flow to the surface (e.g. during warm weather or strenuous exercise) causes warmer skin, resulting in faster heat loss, while decreasing surface blood flow conserves heat. Hydraulic functions The restriction of blood flow can also be used in specialized tissues to cause engorgement resulting in an erection of that tissue. Examples of this would occur in a mammalian penis, clitoris or nipple. Another example of a hydraulic function is the jumping spider, in which blood forced into the legs under pressure causes them to straighten for a powerful jump. Color In humans and other hemoglobin-using creatures, oxygenated blood is bright red. This is due to oxygenated iron in the red blood cells. Deoxygenated blood is a darker shade of red, which can be seen during blood donation and when venous blood samples are taken. However, due to skin pigments, blood vessel coverings and an optical effect caused by the way in which light penetrates through the skin, veins typically appear blue in color. This has led to a common misconception that venous blood is blue before it is exposed to air. Another reason for this misconception is that medical charts always show venous blood as blue in order to distinguish it from arterial blood which is depicted as red on the same chart. The blood of horseshoe crabs is blue, which is a result of its high content in Copper-based hemocyanin instead of the iron-based hemoglobin found, for example, in humans. Health and disease Ancient Medicine Hippocratic medicine considered blood one of the four humors (together with phlegm, yellow bile and black bile). As many diseases were thought to be due to an excess of blood, bloodletting and leeching were a common intervention until the 19th century (it is still used for some rare blood disorders). In classical Greek medicine, blood was associated with air, springtime, and with a merry and gluttonous (sanguine) personality. It was also believed to be produced exclusively by the liver. Diagnosis Blood pressure and blood tests are amongst the most commonly performed diagnostic investigations that directly concern the blood. Pathology See also: Blood diseases Problems with blood circulation and composition play a role in many diseases. Wounds can cause major blood loss (see bleeding). The thrombocytes cause the blood to coagulate, blocking relatively minor wounds, but larger ones must be repaired at speed to prevent exsanguination. Damage to the internal organs can cause severe internal bleeding, or hemorrhage. Circulation blockage can also create many medical conditions from ischemia in the short term to tissue necrosis and gangrene in the long term. Hemophilia is a genetic illness that causes dysfunction in one of the blood's clotting mechanisms. This can allow otherwise inconsequential wounds to be life-threatening, but more commonly results in hemarthrosis, or bleeding into joint spaces, which can be crippling. Leukemia is a group of cancers of the blood-forming tissues. Major blood loss, whether traumatic or not (e.g. during surgery), as well as certain blood diseases like anemia and thalassemia, can require blood transfusion. Several countries have blood banks to fill the demand for transfusable blood. A person receiving a blood transfusion must have a blood type compatible with that of the donor. Overproduction of red blood cells is called polycythemia. Blood is an important vector of infection. HIV, the virus which causes AIDS, is transmitted through contact between blood, semen, or the bodily secretions of an infected person. Hepatitis B and C are transmitted primarily through blood contact. Owing to blood-borne infections, bloodstained objects are treated as a biohazard. Bacterial infection of the blood is bacteremia or sepsis. Viral Infection is viremia. Malaria and trypanosomiasis are blood-borne parasitic infections. Treatment Blood transfusion is the most direct therapeutic use of blood. It is obtained from human donors by blood donation. As there are different blood types, and transfusion of the incorrect blood may cause severe complications, crossmatching is done to ascertain the correct type is transfused. Other blood products administered intravenously are platelets, blood plasma, cryoprecipitate and specific coagulation factor concentrates. Many forms of medication (from antibiotics to chemotherapy) are administered intravenously, as they are not readily or adequately absorbed by the digestive tract. As stated above, some diseases are still treated by removing blood from the circulation. It is the fluid part of the blood that saves lives where severe blood loss occurs, other preparations can be given such as ringers atopical plasma Volume Expander as a non-blood alternative, and these alternatives where used are rivalling blood use when used. Mythology and religion Due to its importance to life, blood is associated with a large number of beliefs. One of the most basic is the use of blood as a symbol for family relationships; to be "related by blood" is to be related by ancestry or descendance, rather than marriage. This bears closely to bloodlines, and sayings such as "blood is thicker than water" and "bad blood", as well as "Blood brother". Blood is given particular emphasis in the Jewish and Christian religions because (Leviticus 17:11) says "the life of a creature is in the blood." Indigenous Australians In many indigenous Australian Aboriginal peoples' traditions ochre (particularly red) and blood, both high in iron content and considered Maban, are applied to the bodies of dancers for ritual. As Lawlor states: In many Aboriginal rituals and ceremonies, red ochre is rubbed all over the naked bodies of the dancers. In secret, sacred male ceremonies, blood extracted from the veins of the participant's arms is exchanged and rubbed on their bodies. Red ochre is used in similar ways in less secret ceremonies. Blood is also used to fasten the feathers of birds onto people's bodies. Bird feathers contain a protein that is highly magnetically sensitive. [9] Lawlor comments that blood employed in this fashion is held by these peoples to attune the dancers to the invisible energetic realm of the Dreamtime. Lawlor then draws information from different disciplines charting a relationship between these invisible energetic realms and magnetic fields. Iron and magnetism having a marked relationship. Indo-European paganism Among the Germanic tribes (such as the Anglo-Saxons and the Norsemen), blood was used during the sacrifices, the Blóts. The blood was considered to have the power of its originator and after the butchering the blood was sprinkled on the walls, on the statues of the gods and on the participants themselves. This act of sprinkling blood was called bleodsian in Old English and the terminology was borrowed by the Roman Catholic Church becoming to bless and blessing. The Hittite word for blood, ishar was a cognate to words for "oath" and "bond", see Ishara. The Ancient Greeks believed that the blood of the Gods, ichor, was a mineral that was poisonous to mortals. Judaism In Judaism, blood cannot be consumed even in the smallest quantity (Leviticus 3:17 and elsewhere); this is reflected in Jewish dietary laws (Kashrut). Blood is purged from meat by salting and soaking in water. Other rituals involving blood are the covering of the blood of fowl and game after slaughtering (Leviticus 17:13); the reason given by the Torah is: "Because the life of every animal is [in] his blood" (ibid 17:14), although from its context in Leviticus 3:17 it would appear that blood cannot be consumed because it is to be used in the sacrificial service (known as the korbanot), in the Temple in Jerusalem. Blood (the blood of a lamb) was also the means for atonement of sins for the Jews. Christianity Main article: Eucharist Some Christian churches, including Roman Catholicism, Eastern Orthodoxy, branches of Anglicanism, and the Moravian Church, teach that when consecrated the Eucharist wine becomes the material Blood of Jesus. Thus in the consecrated wine (now the Most Precious Blood of Christ), Jesus becomes spiritually and physically present. This teaching is rooted in the Last Supper as written in the four gospels of the Bible, in which Jesus stated to his disciples that the bread which they ate was his body, and the wine was his blood. "This cup is the new testament in my blood, which is shed for you." (Luke 22:20). Various forms of Protestantism, especially those of a Wesleyan or Presbyterian lineage, teach that the wine is no more than a symbol of the blood of Christ, who is not physically but spiritually present. Blood (the blood of Jesus Christ) is also seen as the means for atonement for sins for Christians. Lutheran theology teaches that the body and blood is present together "in, with, and under" the bread and wine of the eucharist feast. Mormons believe that before Adam and Eve ate the forbidden fruit, blood was not present in their bodies. It is said to have formed after the Fall when they became mortal. Islam Consumption of food containing blood is forbidden by Islamic dietary laws. Jehovah's Witnesses Main article: Jehovah's Witnesses and blood Due to Bible-based beliefs, Jehovah's Witnesses do not eat blood or accept tranfusions of whole blood or its four major components namely, red blood cells, white blood cells, platelets (thrombocytes), and whole plasma. Members are instructed to personally decide whether or not to accept fractions, and medical procedures that involve their own blood. Vampire legends Vampires are mythological beings which live forever by drinking the blood of the living. Stories of creatures of this kind are known all over the world. European versions of this myth are mostly inspired by folklore based on the stories regarding Vlad Dracula.[citation needed] Chinese and Japanese culture In Chinese culture, it is often said that if a man's nose produces a small flow of blood, this signifies that he is experiencing sexual desire. This often appears in Chinese-language and Hong Kong films. This is also evident in Japanese culture and is parodied in anime and manga. Male characters will often be shown with a nosebleed if they have just seen a female nude or in little clothing, or if they have had an erotic thought or fantasy.[citation needed] Blood libel Main article: Blood libel Various religious and other groups have been falsely accused of using human blood in rituals; such accusations are known as blood libel. The most common form of this is blood libel against Jews. Although there is no ritual involving human blood in Jewish law or custom, fabrications of this nature (often involving the murder of children) were widely used during the Middle Ages to justify anti-Semitic persecution and some have persisted into the 21st century. Art Blood is one of the body fluids that has been used in art.[10] In particular, the performances of Viennese Actionist Hermann Nitsch, Franko B, Lennie Lee, Ron Athey, Yang Zhichao and Kira O' Reilly along with the photography of Andres Serrano, have incorporated blood as a prominent visual element. Marc Quinn has made sculptures using frozen blood, including a cast of his own head made using his own blood. Was this answer helpful to you? Yes / No

freddy	It would not be seen if it were clear.And so you may bleed to death Was this answer helpful to you? Yes / No

iloverockclimbing11	blood isnt red its only red when it hits oxegyn but originally its blue or purple. Was this answer helpful to you? Yes / No

allon e	blood is neither red nor blue. It reflects red and blue light depending upon oxygen exposure. It is in fact comprised of all colors save for red and blue. Was this answer helpful to you? Yes / No

GD-Fan	it's blue but, the oxygen makes it red Was this answer helpful to you? Yes / No

yeah!	so you can see it when you bleed. Its like a red light or tail lights on a car, when you see red, you stop. So when you bleed you see red, you stop, you put on a bandaid, or other care if its serious. Was this answer helpful to you? Yes / No

Deez	It looks cool. Was this answer helpful to you? Yes / No

Will S	Blood has two colers it is red when the blood cell is caring oxygen and it turns to a purple like color when the blood cell is not caring oxygen. Also the blood cell is in a dougnut shape because it has no nucleas with allows the cell to carry more oxygen throughout your body. Was this answer helpful to you? Yes / No

BeautifulGirl	Blood is red because blood absorbs all the other colors of the visible Spectrum, except for red. So red is transmitted instead. Get it. P.S. I took Biology, Chemistry, and Physics in college. Was this answer helpful to you? Yes / No

pinkgirl	i think it is because of your red blood cells Was this answer helpful to you? Yes / No

Elizabeth Magic Wings	its not the blood thats red its the blood CELLS. Was this answer helpful to you? Yes / No

im emo, who cares	red blood cells Was this answer helpful to you? Yes / No

dazcorupt	Good question! When u find out why ... let me know. Was this answer helpful to you? Yes / No

Michael S	It is a chemical reaction between ingredients in blood and oxygen that turn it red. When the blood passes through the arteries it receives oxygen from the lungs and the blood turns red. The blood traveling back to the heart has been depleted of oxygen since that is one of the main purposes of blood, to bring oxygen to all of the cells. That is why veins are blue and arteries are red. Though there are "red blood" cells in the mix they are not red unless they are rich in oxygen. It is hemoglobin in the cells that actually carry the oxygen. I believe it is the reaction between oxygen and iron that makes the red color, like rust forming when iron is over exposed to air. Was this answer helpful to you? Yes / No

ya ok....sure	hemoglobin Was this answer helpful to you? Yes / No

Emmy	Ugh. People, it's not blue. It's never blue. Unoxygenated blood is a darker red, and the darker color makes your veins look blue. When you draw venous blood into a vacutainer, which is a vacuum, so no air, it's dark red, arterial blood is bright red. Blue is an old wives tale. That out of the way, blood is red because hemoglobin is red. Hemoglobin is a protein molecule bonded with iron that binds oxygen in the red cells to transport it to your body tissues. The protein and iron complex has a red color, which is intensified by the presence of oxygen. Was this answer helpful to you? Yes / No

sam	blood is red because of a pigment called haemoglobin in blood which imparts red colour Was this answer helpful to you? Yes / No

swomedicineman	Blood is a highly specialized circulating tissue consisting of several types of cells suspended in a fluid medium known as plasma. The cellular constituents are: red blood cells (erythrocytes), which carry respiratory gases and give it its red color because they contain hemoglobin (an iron-containing protein that binds oxygen in the lungs and transports it to tissues in the body), white blood cells (leukocytes), which fight disease, and platelets (thrombocytes), cell fragments which play an important part in the clotting of the blood. Was this answer helpful to you? Yes / No

TheEconomist	Because it contains iron, which oxidizes (the same process as rusting!) when exposed to oxygen. Blood in the veins isn't red! Was this answer helpful to you? Yes / No

ralucation	The blood is red because it contains iron. Its colour varies according to the amount of oxygen it contains. For example our veins contain the blood which collects the carbon dioxide from our body and takes it to the lungs; the blood has a col or a little bit darker than the blood in our arteries which are found deeper in our body and which contains blood with oxygen. Was this answer helpful to you? Yes / No

willmakxam	same reason why iron ore rusts to a red colour. We have iron in our blood stream. Hence it appears to be red. Darker blood consists of Carbon dioxide (carried by the veins) and the brighter red (usually seen when scratching skin) is full of Oxygen. Was this answer helpful to you? Yes / No

keypointist	It's due to the heamoglobin molecules it contains. These are red coloured iron complexes. Was this answer helpful to you? Yes / No

*****	Hemoglobin is what make the blood a red color. Was this answer helpful to you? Yes / No

dana_osmundson	When the iron in blood meets with oxygen, it makes it a red color. It's the same principle behind when iron rusts, it looks red. Was this answer helpful to you? Yes / No

gordon r	lmao@bllod is blue..wtf are u's all on i had blood took into a syringe which has no oxygen in and it was red so shut up...its red because that is the colour it is Was this answer helpful to you? Yes / No

stevers1	The Hemoglobin molecule is red when attached to a oxygen molecule, it is not red when the O2 is not attached. Was this answer helpful to you? Yes / No