Blood

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Blood
Venous and arterial blood.jpg
Venous (darker) and arterial (brighter) blood
Identifiers
MeSH D001769
TA98 A12.0.00.009
TA2 3892
FMA 9670
Anatomical terminology

Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. [1]

Contents

Blood is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), [2] and contains proteins, glucose, mineral ions, and hormones. The blood cells are mainly red blood cells (erythrocytes), white blood cells (leukocytes), and (in mammals) platelets (thrombocytes). [3] The most abundant cells are red blood cells. [4] These contain hemoglobin, which facilitates oxygen transport by reversibly binding to it, increasing its solubility. [5] Jawed vertebrates have an adaptive immune system, based largely on white blood cells. White blood cells help to resist infections and parasites. Platelets are important in the clotting of blood.

Blood is circulated around the body through blood vessels by the pumping action of the heart. In animals with lungs, arterial blood carries oxygen from inhaled air to the tissues of the body, and venous blood carries carbon dioxide, a waste product of metabolism produced by cells, from the tissues to the lungs to be exhaled. Blood is bright red when its hemoglobin is oxygenated and dark red when it is deoxygenated. [6] [7]

Medical terms related to blood often begin with hemo-, hemato-, haemo- or haemato- from the Greek word αἷμα (haima) for "blood". In terms of anatomy and histology, blood is considered a specialized form of connective tissue, [8] given its origin in the bones and the presence of potential molecular fibers in the form of fibrinogen.[ citation needed ]

Functions

Hemoglobin, a globular protein
green = haem (or heme) groups
red & blue = protein subunits 1GZX Haemoglobin.png
Hemoglobin, a globular protein
green = haem (or heme) groups
red & blue = protein subunits

Blood performs many important functions within the body, including:

Constituents

In mammals

Blood accounts for 7% of the human body weight, [9] [10] with an average density around 1060 kg/m3, very close to pure water's density of 1000 kg/m3. [11] The average adult has a blood volume of roughly 5 litres (11 US pt) or 1.3 gallons, [10] which is composed of plasma and formed elements. The formed elements are the two types of blood cell or corpuscle – the red blood cells, (erythrocytes) and white blood cells (leukocytes), and the cell fragments called platelets [12] that are involved in clotting. By volume, the red blood cells constitute about 45% of whole blood, the plasma about 54.3%, and white cells about 0.7%.

Whole blood (plasma and cells) exhibits non-Newtonian fluid dynamics.[ specify ]

Cells

A scanning electron microscope (SEM) image of a normal red blood cell (left), a platelet (middle), and a white blood cell (right) Red White Blood cells.jpg
A scanning electron microscope (SEM) image of a normal red blood cell (left), a platelet (middle), and a white blood cell (right)

One microliter of blood contains:

  • 4.7 to 6.1 million (male), 4.2 to 5.4 million (female) erythrocytes: [13] Red blood cells contain the blood's hemoglobin and distribute oxygen. Mature red blood cells lack a nucleus and organelles in mammals. The red blood cells (together with endothelial vessel cells and other cells) are also marked by glycoproteins that define the different blood types. The proportion of blood occupied by red blood cells is referred to as the hematocrit, and is normally about 45%. The combined surface area of all red blood cells of the human body would be roughly 2,000 times as great as the body's exterior surface. [14]
  • 4,000–11,000 leukocytes: [15] White blood cells are part of the body's immune system; they destroy and remove old or aberrant cells and cellular debris, as well as attack infectious agents (pathogens) and foreign substances. The cancer of leukocytes is called leukemia.
  • 200,000–500,000 thrombocytes: [15] Also called platelets, they take part in blood clotting (coagulation). Fibrin from the coagulation cascade creates a mesh over the platelet plug.
Constitution of normal blood
ParameterValueRefs.
Hematocrit

45 ± 7 (38–52%) for males
42 ± 5 (37–47%) for females

pH 7.35–7.45 [16]
base excess −3 to +3
PO2 10–13 kPa (80–100 mm Hg)
PCO2 4.8–5.8 kPa (35–45 mm Hg)
HCO3 21–27 mM
Oxygen saturation

Oxygenated: 98–99%
Deoxygenated: 75%

Plasma

About 55% of blood is blood plasma, a fluid that is the blood's liquid medium, which by itself is straw-yellow in color. The blood plasma volume totals of 2.7–3.0 liters (2.8–3.2 quarts) in an average human. It is essentially an aqueous solution containing 92% water, 8% blood plasma proteins, and trace amounts of other materials. Plasma circulates dissolved nutrients, such as glucose, amino acids, and fatty acids (dissolved in the blood or bound to plasma proteins), and removes waste products, such as carbon dioxide, urea, and lactic acid.

Other important components include:

The term serum refers to plasma from which the clotting proteins have been removed. Most of the proteins remaining are albumin and immunoglobulins.

Acidity

Blood pH is regulated to stay within the narrow range of 7.35 to 7.45, making it slightly basic (compensation). [17] [18] Extra-cellular fluid in blood that has a pH below 7.35 is too acidic, whereas blood pH above 7.45 is too basic. [16] A pH below 6.9 or above 7.8 is usually lethal. [16] Blood pH, partial pressure of oxygen (pO2), partial pressure of carbon dioxide (pCO2), and bicarbonate (HCO3) are carefully regulated by a number of homeostatic mechanisms, which exert their influence principally through the respiratory system and the urinary system to control the acid–base balance and respiration, which is called compensation. [16] An arterial blood gas test measures these. Plasma also circulates hormones transmitting their messages to various tissues. The list of normal reference ranges for various blood electrolytes is extensive.

In non-mammals

Vertebrate red blood cell types, measurements in micrometers Newbloodm.jpg
Vertebrate red blood cell types, measurements in micrometers
Frog red blood cells magnified 1000 times Frogrbc1000x.jpg
Frog red blood cells magnified 1000 times
Turtle red blood cells magnified 1000 times Turtlerbc1000x.jpg
Turtle red blood cells magnified 1000 times
Chicken red blood cells magnified 1000 times Chickenrbc1000x.jpg
Chicken red blood cells magnified 1000 times
Human red blood cells magnified 1000 times Humanrbc1000x.jpg
Human red blood cells magnified 1000 times

Human blood is typical of that of mammals, although the precise details concerning cell numbers, size, protein structure, and so on, vary somewhat between species. In non-mammalian vertebrates, however, there are some key differences: [19]

Physiology

Circulatory system

Circulation of blood through the human heart Diagram of the human heart (cropped).svg
Circulation of blood through the human heart

Blood is circulated around the body through blood vessels by the pumping action of the heart. In humans, blood is pumped from the strong left ventricle of the heart through arteries to peripheral tissues and returns to the right atrium of the heart through veins. It then enters the right ventricle and is pumped through the pulmonary artery to the lungs and returns to the left atrium through the pulmonary veins. Blood then enters the left ventricle to be circulated again. Arterial blood carries oxygen from inhaled air to all of the cells of the body, and venous blood carries carbon dioxide, a waste product of metabolism by cells, to the lungs to be exhaled. However, one exception includes pulmonary arteries, which contain the most deoxygenated blood in the body, while the pulmonary veins contain oxygenated blood.

Additional return flow may be generated by the movement of skeletal muscles, which can compress veins and push blood through the valves in veins toward the right atrium.

The blood circulation was famously described by William Harvey in 1628. [20]

Cell production and degradation

In vertebrates, the various cells of blood are made in the bone marrow in a process called hematopoiesis, which includes erythropoiesis, the production of red blood cells; and myelopoiesis, the production of white blood cells and platelets. During childhood, almost every human bone produces red blood cells; as adults, red blood cell production is limited to the larger bones: the bodies of the vertebrae, the breastbone (sternum), the ribcage, the pelvic bones, and the bones of the upper arms and legs. In addition, during childhood, the thymus gland, found in the mediastinum, is an important source of T lymphocytes. [21] The proteinaceous component of blood (including clotting proteins) is produced predominantly by the liver, while hormones are produced by the endocrine glands and the watery fraction is regulated by the hypothalamus and maintained by the kidney.

Healthy erythrocytes have a plasma life of about 120 days before they 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.

Oxygen transport

Basic hemoglobin saturation curve. It is moved to the right in higher acidity (more dissolved carbon dioxide) and to the left in lower acidity (less dissolved carbon dioxide) Oxyhaemoglobin dissociation curve.png
Basic hemoglobin saturation curve. It is moved to the right in higher acidity (more dissolved carbon dioxide) and to the left in lower acidity (less dissolved carbon dioxide)

About 98.5% [22] of the oxygen in a sample of arterial blood in a healthy human breathing air at sea-level pressure is chemically combined with the hemoglobin. About 1.5% is physically dissolved in the other blood liquids and not connected to hemoglobin. The hemoglobin molecule is the primary transporter of oxygen in mammals and many other species. Hemoglobin has an oxygen binding capacity between 1.36 and 1.40 ml O2 per gram hemoglobin, [23] which increases the total blood oxygen capacity seventyfold, [24] compared to if oxygen solely were carried by its solubility of 0.03 ml O2 per liter blood per mm Hg partial pressure of oxygen (about 100 mm Hg in arteries). [24]

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.

Under normal conditions in adult humans at rest, hemoglobin in blood leaving the lungs is about 98–99% saturated with oxygen, achieving an oxygen delivery between 950 and 1150 ml/min [25] to the body. In a healthy adult at rest, oxygen consumption is approximately 200–250 ml/min, [25] and deoxygenated blood returning to the lungs is still roughly 75% [26] [27] (70 to 78%) [25] saturated. 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. [28] Oxygen saturation this low is considered dangerous in an individual at rest (for instance, during surgery under anesthesia). Sustained hypoxia (oxygenation less than 90%), is dangerous to health, and severe hypoxia (saturations less than 30%) may be rapidly fatal. [29]

A fetus, receiving oxygen via the placenta, is exposed to much lower oxygen pressures (about 21% of the level found in an adult's lungs), so fetuses produce another form of hemoglobin with a much higher affinity for oxygen (hemoglobin F) to function under these conditions. [30]

Carbon dioxide transport

CO2 is carried in blood in three different ways. (The exact percentages vary depending whether it is arterial or venous blood). Most of it (about 70%) is converted to bicarbonate ions HCO3 by the enzyme carbonic anhydrase in the red blood cells by the reaction CO2 + H2O → H2CO3 → H+ + HCO3; about 7% is dissolved in the plasma; and about 23% is bound to hemoglobin as carbamino compounds. [31] [32]

Hemoglobin, the main oxygen-carrying molecule in red blood cells, carries both oxygen and carbon dioxide. However, the CO2 bound to hemoglobin does not bind to the same site as oxygen. Instead, it combines with the N-terminal groups on the four globin chains. However, because of allosteric effects on the hemoglobin molecule, the binding of CO2 decreases the amount of oxygen that is bound for a given partial pressure of oxygen. The decreased binding to carbon dioxide in the blood due to increased oxygen levels is known as the Haldane effect, and is important in the transport of carbon dioxide from the tissues to the lungs. A rise in the partial pressure of CO2 or a lower pH will cause offloading of oxygen from hemoglobin, which is known as the Bohr effect.

Transport of hydrogen ions

Some oxyhemoglobin loses oxygen and becomes deoxyhemoglobin. Deoxyhemoglobin binds most of the hydrogen ions as it has a much greater affinity for more hydrogen than does oxyhemoglobin.

Lymphatic system

In mammals, blood is in equilibrium with lymph, which is continuously formed in tissues from blood by capillary ultrafiltration. Lymph is collected by a system of small lymphatic vessels and directed to the thoracic duct, which drains into the left subclavian vein, where lymph rejoins the systemic blood circulation.

Thermoregulation

Blood circulation transports heat throughout 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. In contrast, when the external temperature is low, blood flow to the extremities and surface of the skin is reduced and to prevent heat loss and is circulated to the important organs of the body, preferentially.

Rate of flow

Rate of blood flow varies greatly between different organs. Liver has the most abundant blood supply with an approximate flow of 1350 ml/min. Kidney and brain are the second and the third most supplied organs, with 1100 ml/min and ~700 ml/min, respectively. [33]

Relative rates of blood flow per 100 g of tissue are different, with kidney, adrenal gland and thyroid being the first, second and third most supplied tissues, respectively. [33]

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 are the erectile tissue in the penis and clitoris.

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, without the need for bulky muscular legs. [34]

Color

Capillary blood from a bleeding finger Bleeding finger.jpg
Capillary blood from a bleeding finger

Hemoglobin is the principal determinant of the color of blood (hemochrome). Each molecule has four heme groups, and their interaction with various molecules alters the exact color. Arterial blood and capillary blood are bright red, as oxygen imparts a strong red color to the heme group. Deoxygenated blood is a darker shade of red; this is present in veins, and can be seen during blood donation and when venous blood samples are taken. This is because the spectrum of light absorbed by hemoglobin differs between the oxygenated and deoxygenated states. [35]

Blood in carbon monoxide poisoning is bright red, because carbon monoxide causes the formation of carboxyhemoglobin. In cyanide poisoning, the body cannot use oxygen, so the venous blood remains oxygenated, increasing the redness. There are some conditions affecting the heme groups present in hemoglobin that can make the skin appear blue – a symptom called cyanosis. If the heme is oxidized, methemoglobin, which is more brownish and cannot transport oxygen, is formed. In the rare condition sulfhemoglobinemia, arterial hemoglobin is partially oxygenated, and appears dark red with a bluish hue.

Veins close to the surface of the skin appear blue for a variety of reasons. However, the factors that contribute to this alteration of color perception are related to the light-scattering properties of the skin and the processing of visual input by the visual cortex, rather than the actual color of the venous blood. [36]

Skinks in the genus Prasinohaema have green blood due to a buildup of the waste product biliverdin. [37]

Disorders

General medical

Hematological

Carbon monoxide poisoning

Substances other than oxygen can bind to hemoglobin; in some cases, this can cause irreversible damage to the body. Carbon monoxide, for example, is extremely dangerous when carried to the blood via the lungs by inhalation, because carbon monoxide irreversibly binds to hemoglobin to form carboxyhemoglobin, so that less hemoglobin is free to bind oxygen, and fewer oxygen molecules can be transported throughout the blood. This can cause suffocation insidiously. A fire burning in an enclosed room with poor ventilation presents a very dangerous hazard, since it can create a build-up of carbon monoxide in the air. Some carbon monoxide binds to hemoglobin when smoking tobacco. [40]

Treatments

Transfusion

Venous blood collected during blood donation Bloodbags.jpg
Venous blood collected during blood donation

Blood for transfusion is obtained from human donors by blood donation and stored in a blood bank. There are many different blood types in humans, the ABO blood group system, and the Rhesus blood group system being the most important. Transfusion of blood of an incompatible blood group may cause severe, often fatal, complications, so crossmatching is done to ensure that a compatible blood product is transfused.

Other blood products administered intravenously are platelets, blood plasma, cryoprecipitate, and specific coagulation factor concentrates.

Intravenous administration

Many forms of medication (from antibiotics to chemotherapy) are administered intravenously, as they are not readily or adequately absorbed by the digestive tract.

After severe acute blood loss, liquid preparations, generically known as plasma expanders, can be given intravenously, either solutions of salts (NaCl, KCl, CaCl2 etc.) at physiological concentrations, or colloidal solutions, such as dextrans, human serum albumin, or fresh frozen plasma. In these emergency situations, a plasma expander is a more effective life-saving procedure than a blood transfusion, because the metabolism of transfused red blood cells does not restart immediately after a transfusion.

Letting

In modern evidence-based medicine, bloodletting is used in management of a few rare diseases, including hemochromatosis and polycythemia. However, bloodletting and leeching were common unvalidated interventions used until the 19th century, as many diseases were incorrectly thought to be due to an excess of blood, according to Hippocratic medicine.

Etymology

Jan Jansky is credited with the first classification of blood into four types (A, B, AB, and O) Jan Jansky, 1902.jpg
Jan Janský is credited with the first classification of blood into four types (A, B, AB, and O)

English blood (Old English blod) derives from Germanic and has cognates with a similar range of meanings in all other Germanic languages (e.g. German Blut, Swedish blod, Gothic blōþ). There is no accepted Indo-European etymology. [41]

History

Classical Greek medicine

Robin Fåhræus (a Swedish physician who devised the erythrocyte sedimentation rate) suggested that the Ancient Greek system of humorism, wherein the body was thought to contain four distinct bodily fluids (associated with different temperaments), were based upon the observation of blood clotting in a transparent container. When blood is drawn in a glass container and left undisturbed for about an hour, four different layers can be seen. A dark clot forms at the bottom (the "black bile"). Above the clot is a layer of red blood cells (the "blood"). Above this is a whitish layer of white blood cells (the "phlegm"). The top layer is clear yellow serum (the "yellow bile"). [42] [ failed verification ]

Types

The ABO blood group system was discovered in the year 1900 by Karl Landsteiner. Jan Janský is credited with the first classification of blood into the four types (A, B, AB, and O) in 1907, which remains in use today. In 1907 the first blood transfusion was performed that used the ABO system to predict compatibility. [43] The first non-direct transfusion was performed on 27 March 1914. The Rhesus factor was discovered in 1937.

Culture 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 through birth/parentage; to be "related by blood" is to be related by ancestry or descendence, 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 Islamic, Jewish, and Christian religions, because Leviticus 17:11 says "the life of a creature is in the blood." This phrase is part of the Levitical law forbidding the drinking of blood or eating meat with the blood still intact instead of being poured off.

Mythic references to blood can sometimes be connected to the life-giving nature of blood, seen in such events as childbirth, as contrasted with the blood of injury or death.

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. [44]

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 connects these invisible energetic realms and magnetic fields, because iron is magnetic.

European paganism

Among the Germanic tribes, blood was used during their 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 blóedsian 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 substance that was poisonous to mortals.

As a relic of Germanic Law, the cruentation, an ordeal where the corpse of the victim was supposed to start bleeding in the presence of the murderer, was used until the early 17th century. [45]

Christianity

In Genesis 9:4, God prohibited Noah and his sons from eating blood (see Noahide Law). This command continued to be observed by the Eastern Orthodox Church.

It is also found in the Bible that when the Angel of Death came around to the Hebrew house that the first-born child would not die if the angel saw lamb's blood wiped across the doorway.

At the Council of Jerusalem, the apostles prohibited certain Christians from consuming blood – this is documented in Acts 15:20 and 29. This chapter specifies a reason (especially in verses 19–21): It was to avoid offending Jews who had become Christians, because the Mosaic Law Code prohibited the practice.

Christ's blood is the means for the atonement of sins. Also, "... the blood of Jesus Christ his [God] Son cleanseth us from all sin." (1 John 1:7), "... Unto him [God] that loved us, and washed us from our sins in his own blood." (Revelation 1:5), and "And they overcame him (Satan) by the blood of the Lamb [Jesus the Christ], and by the word of their testimony ..." (Revelation 12:11).

Some Christian churches, including Roman Catholicism, Eastern Orthodoxy, Oriental Orthodoxy, and the Assyrian Church of the East teach that, when consecrated, the Eucharistic wine actually becomes the blood of Jesus for worshippers to drink. Thus in the consecrated wine, 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 that 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." (Luke22:20).

Most forms of Protestantism, especially those of a Methodist or Presbyterian lineage, teach that the wine is no more than a symbol of the blood of Christ, who is spiritually but not physically present. Lutheran theology teaches that the body and blood is present together "in, with, and under" the bread and wine of the Eucharistic feast.

Judaism

In Judaism, animal blood may not 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 rinsing and soaking in water (to loosen clots), salting and then rinsing with water again several times. [46] Eggs must also be checked and any blood spots removed before consumption. [47] Although blood from fish is biblically kosher, it is rabbinically forbidden to consume fish blood to avoid the appearance of breaking the Biblical prohibition. [48]

Another ritual involving blood involves 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 the animal is [in] its blood" (ibid 17:14). In relation to human beings, Kabbalah expounds on this verse that the animal soul of a person is in the blood, and that physical desires stem from it.

Likewise, the mystical reason for salting temple sacrifices and slaughtered meat is to remove the blood of animal-like passions from the person. By removing the animal's blood, the animal energies and life-force contained in the blood are removed, making the meat fit for human consumption. [49]

Islam

Consumption of food containing blood is forbidden by Islamic dietary laws. This is derived from the statement in the Qur'an, sura Al-Ma'ida (5:3): "Forbidden to you (for food) are: dead meat, blood, the flesh of swine, and that on which has been invoked the name of other than Allah."

Blood is considered unclean, hence there are specific methods to obtain physical and ritual status of cleanliness once bleeding has occurred. Specific rules and prohibitions apply to menstruation, postnatal bleeding and irregular vaginal bleeding. When an animal has been slaughtered, the animal's neck is cut in a way to ensure that the spine is not severed, hence the brain may send commands to the heart to pump blood to it for oxygen. In this way, blood is removed from the body, and the meat is generally now safe to cook and eat. In modern times, blood transfusions are generally not considered against the rules.

Jehovah's Witnesses

Based on their interpretation of scriptures such as Acts 15:28, 29 ("Keep abstaining...from blood."), many Jehovah's Witnesses neither consume blood nor accept transfusions of whole blood or its major components: red blood cells, white blood cells, platelets (thrombocytes), and plasma. Members may personally decide whether they will accept medical procedures that involve their own blood or substances that are further fractionated from the four major components. [50]

Vampirism

Vampires are mythical creatures that drink blood directly for sustenance, usually with a preference for human blood. Cultures all over the world have myths of this kind; for example the 'Nosferatu' legend, a human who achieves damnation and immortality by drinking the blood of others, originates from Eastern European folklore. Ticks, leeches, female mosquitoes, vampire bats, and an assortment of other natural creatures do consume the blood of other animals, but only bats are associated with vampires. This has no relation to vampire bats, which are New World creatures discovered well after the origins of the European myths.

Invertebrates

In invertebrates, a body fluid analogous to blood called hemolymph is found, the main difference being that hemolymph is not contained in a closed circulatory system. Hemolymph may function to carry oxygen, although hemoglobin is not necessarily used. Crustaceans and mollusks use hemocyanin instead of hemoglobin. [51] In most insects, their hemolymph does not contain oxygen-carrying molecules because their bodies are small enough for their tracheal system to suffice for supplying oxygen.

Other uses

Forensic and archaeological

Blood residue can help forensic investigators identify weapons, reconstruct a criminal action, and link suspects to the crime. Through bloodstain pattern analysis, forensic information can also be gained from the spatial distribution of bloodstains.

Blood residue analysis is also a technique used in archeology.

Artistic

Blood is one of the body fluids that has been used in art. [52] In particular, the performances of Viennese Actionist Hermann Nitsch, Istvan Kantor, Franko B, Lennie Lee, Ron Athey, Yang Zhichao, Lucas Abela 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.

Genealogical

The term blood is used in genealogical circles to refer to one's ancestry, origins, and ethnic background as in the word bloodline . Other terms where blood is used in a family history sense are blue-blood , royal blood , mixed-blood and blood relative .

See also

Related Research Articles

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Blood plasma is a light amber-colored liquid component of blood in which blood cells are absent, however contains proteins and other constituents of whole blood in suspension. It makes up about 55% of the body's total blood volume. It is the intravascular part of extracellular fluid. It is mostly water, and contains important dissolved proteins, glucose, clotting factors, electrolytes, hormones, carbon dioxide, and oxygen. It plays a vital role in an intravascular osmotic effect that keeps electrolyte concentration balanced and protects the body from infection and other blood-related disorders.

<span class="mw-page-title-main">Extracellular fluid</span> Body fluid outside the cells of a multicellular organism

In cell biology, extracellular fluid (ECF) denotes all body fluid outside the cells of any multicellular organism. Total body water in healthy adults is about 50–60% of total body weight; women and the obese typically have a lower percentage than lean men. Extracellular fluid makes up about one-third of body fluid, the remaining two-thirds is intracellular fluid within cells. The main component of the extracellular fluid is the interstitial fluid that surrounds cells.

The Fick principle states that blood flow to an organ can be calculated using a marker substance if the following information is known:

<span class="mw-page-title-main">Coagulopathy</span> Condition involving impaired blood clotting ability

Coagulopathy is a condition in which the blood's ability to coagulate is impaired. This condition can cause a tendency toward prolonged or excessive bleeding, which may occur spontaneously or following an injury or medical and dental procedures.

<span class="mw-page-title-main">Fetal circulation</span> Circulatory system of fetuses

In humans, the circulatory system is different before and after birth. The fetal circulation is composed of the placenta, umbilical blood vessels encapsulated by the umbilical cord, heart and systemic blood vessels. A major difference between the fetal circulation and postnatal circulation is that the lungs are not used during the fetal stage resulting in the presence of shunts to move oxygenated blood and nutrients from the placenta to the fetal tissue. At birth, the start of breathing and the severance of the umbilical cord prompt various changes that quickly transform fetal circulation into postnatal circulation.

<span class="mw-page-title-main">Oxygen–hemoglobin dissociation curve</span> Visual tool used to understand how human blood carries and releases oxygen

The oxygen–hemoglobin dissociation curve, also called the oxyhemoglobin dissociation curve or oxygen dissociation curve (ODC), is a curve that plots the proportion of hemoglobin in its saturated (oxygen-laden) form on the vertical axis against the prevailing oxygen tension on the horizontal axis. This curve is an important tool for understanding how our blood carries and releases oxygen. Specifically, the oxyhemoglobin dissociation curve relates oxygen saturation (SO2) and partial pressure of oxygen in the blood (PO2), and is determined by what is called "hemoglobin affinity for oxygen"; that is, how readily hemoglobin acquires and releases oxygen molecules into the fluid that surrounds it.

Carbaminohemoglobin (carbaminohaemoglobin BrE) (CO2Hb, also known as carbhemoglobin and carbohemoglobin) is a compound of hemoglobin and carbon dioxide, and is one of the forms in which carbon dioxide exists in the blood. Twenty-three percent of carbon dioxide is carried in blood this way (70% is converted into bicarbonate by carbonic anhydrase and then carried in plasma, 7% carried as free CO2, dissolved in plasma).

The Haldane effect is a property of hemoglobin first described by John Scott Haldane, within which oxygenation of blood in the lungs displaces carbon dioxide from hemoglobin, increasing the removal of carbon dioxide. Consequently, oxygenated blood has a reduced affinity for carbon dioxide. Thus, the Haldane effect describes the ability of hemoglobin to carry increased amounts of carbon dioxide (CO2) in the deoxygenated state as opposed to the oxygenated state. Vice versa, it is true that a high concentration of CO2 facilitates dissociation of oxyhemoglobin, though this is the result of two distinct processes (Bohr effect and Margaria-Green effect) and should be distinguished from Haldane effect.

<span class="mw-page-title-main">Oxygenator</span> Medical equipment

An oxygenator is a medical device that is capable of exchanging oxygen and carbon dioxide in the blood of human patients during surgical procedures that may necessitate the interruption or cessation of blood flow in the body, a critical organ or great blood vessel. These organs can be the heart, lungs or liver, while the great vessels can be the aorta, pulmonary artery, pulmonary veins or vena cava.

<span class="mw-page-title-main">Chloride shift</span> Transfer of ions into red blood cells

Chloride shift (also known as the Hamburger phenomenon or lineas phenomenon, named after Hartog Jakob Hamburger) is a process which occurs in a cardiovascular system and refers to the exchange of bicarbonate (HCO3) and chloride (Cl) across the membrane of red blood cells (RBCs).

<span class="mw-page-title-main">Oxygen saturation (medicine)</span> Medical measurement

Oxygen saturation is the fraction of oxygen-saturated haemoglobin relative to total haemoglobin in the blood. The human body requires and regulates a very precise and specific balance of oxygen in the blood. Normal arterial blood oxygen saturation levels in humans are 96–100 percent. If the level is below 90 percent, it is considered low and called hypoxemia. Arterial blood oxygen levels below 80 percent may compromise organ function, such as the brain and heart, and should be promptly addressed. Continued low oxygen levels may lead to respiratory or cardiac arrest. Oxygen therapy may be used to assist in raising blood oxygen levels. Oxygenation occurs when oxygen molecules enter the tissues of the body. For example, blood is oxygenated in the lungs, where oxygen molecules travel from the air and into the blood. Oxygenation is commonly used to refer to medical oxygen saturation.

Biofluid dynamics may be considered as the discipline of biological engineering or biomedical engineering in which the fundamental principles of fluid dynamics are used to explain the mechanisms of biological flows and their interrelationships with physiological processes, in health and in diseases/disorder. It can be considered as the conjuncture of mechanical engineering and biological engineering. It spans from cells to organs, covering diverse aspects of the functionality of systemic physiology, including cardiovascular, respiratory, reproductive, urinary, musculoskeletal and neurological systems etc. Biofluid dynamics and its simulations in computational fluid dynamics (CFD) apply to both internal as well as external flows. Internal flows such as cardiovascular blood flow and respiratory airflow, and external flows such as flying and aquatic locomotion. Biological fluid Dynamics involves the study of the motion of biological fluids. It can be either circulatory system or respiratory systems. Understanding the circulatory system is one of the major areas of research. The respiratory system is very closely linked to the circulatory system and is very complex to study and understand. The study of Biofluid Dynamics is also directed towards finding solutions to some of the human body related diseases and disorders. The usefulness of the subject can also be understood by seeing the use of Biofluid Dynamics in the areas of physiology in order to explain how living things work and about their motions, in developing an understanding of the origins and development of various diseases related to human body and diagnosing them, in finding the cure for the diseases related to cardiovascular and pulmonary systems.

References

  1. "Definition of BLOOD". Merriam-Webster. Archived from the original on 23 March 2017. Retrieved 4 March 2017.
  2. The Franklin Institute Inc. "Blood – The Human Heart". Archived from the original on 5 March 2009. Retrieved 19 March 2009.
  3. "Definition of red blood cell". National Cancer Institute. 2 February 2011. Archived from the original on 25 April 2022. Retrieved 28 April 2022.
  4. Aryal, Sagar (3 January 2017). "Blood cells and its types with functions". Microbiology Info.com. Archived from the original on 12 April 2022. Retrieved 28 April 2022.
  5. "Low Hemoglobin: Causes & Symptoms". Cleveland Clinic. Archived from the original on 28 April 2022. Retrieved 28 April 2022.
  6. Séguin, Chantal (8 January 2022). "Did You Know That Not All Blood is Red? • The Blood Project". The Blood Project. Archived from the original on 2 July 2022. Retrieved 2 July 2022.
  7. "Is blood blue? 7 facts about blood". www.medicalnewstoday.com. 10 April 2018. Archived from the original on 29 March 2023. Retrieved 29 March 2023.
  8. Krause, William J. (2005). Krause's Essential Human Histology for Medical Students (3rd ed.). Universal-Publishers. p. 67. ISBN   978-1-58112-468-2. Archived from the original on 26 April 2023. Retrieved 21 June 2022.
  9. Alberts B (2012). "Table 22-1 Blood Cells". Molecular Biology of the Cell. NCBI Bookshelf. Archived from the original on 27 March 2018. Retrieved 1 November 2012.
  10. 1 2 Elert G (2012). "Volume of Blood in a Human". The Physics Factbook. Archived from the original on 3 November 2012. Retrieved 1 November 2012.
  11. Shmukler, Michael (2004). "Density of Blood". The Physics Factbook. Archived from the original on 19 September 2006. Retrieved 4 October 2006.
  12. "Composition of the Blood | SEER Training". training.seer.cancer.gov. Archived from the original on 16 October 2020. Retrieved 30 December 2020.
  13. "Medical Encyclopedia: RBC count". Medline Plus. Archived from the original on 21 October 2007. Retrieved 18 November 2007.
  14. Tallitsch RB, Frederic M, Michael J T (2006). Human anatomy (5th ed.). San Francisco: Pearson/Benjamin Cummings. p. 529. ISBN   978-0-8053-7211-3.
  15. 1 2 Ganong WF (2003). Review of medical physiology (21 ed.). New York: Lange Medical Books/McGraw-Hill. p.  518. ISBN   978-0-07-121765-1.
  16. 1 2 3 4 Ignatavicius, Donna D.; Workman, M. Linda; Rebar, Cherie R.; Heimgartner, Nicole M., eds. (2018). Medical-surgical nursing : concepts for interprofessional collaborative care (9th ed.). St. Louis, Missouri: Elsevier. p. 190. ISBN   978-0-323-46158-0. OCLC   1018308697.
  17. Waugh A, Grant A (2007). "2" . Anatomy and Physiology in Health and Illness (Tenth ed.). Churchill Livingstone Elsevier. p. 22. ISBN   978-0-443-10102-1.
  18. Acid–Base Regulation and Disorders at Merck Manual of Diagnosis and Therapy Professional Edition
  19. Romer AS, Parsons TS (1977). The Vertebrate Body . Philadelphia: Holt-Saunders International. pp. 404–406. ISBN   978-0-03-910284-5.
  20. Harvey W (1628). "Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus" (in Latin). Archived from the original on 27 November 2010.
  21. Williams PW, Gray HD (1989). Gray's anatomy (37th ed.). New York: C. Livingstone. ISBN   978-0-443-02588-4.
  22. Frederic, Martini (2009). Fundamentals of anatomy & physiology. Nath, Judi Lindsley (8th ed.). San Francisco: Pearson/Benjamin Cummings. p. 657. ISBN   978-0321539106. OCLC   173683666.
  23. Dominguez de Villota ED, Ruiz Carmona MT, Rubio JJ, de Andrés S (December 1981). "Equality of the in vivo and in vitro oxygen-binding capacity of haemoglobin in patients with severe respiratory disease". British Journal of Anaesthesia. 53 (12): 1325–8. doi: 10.1093/bja/53.12.1325 . PMID   7317251. S2CID   10029560.
  24. 1 2 Costanzo LS (2007). Physiology . Hagerstown, Maryland: Lippincott Williams & Wilkins. ISBN   978-0-7817-7311-9.
  25. 1 2 3 Edwards Lifesciences LLC – Normal Hemodynamic Parameters – Adult Archived 10 November 2010 at the Wayback Machine 2009
  26. "Ventilatory Physiology and Endurance". 23 March 2010. Archived from the original on 23 March 2010. Retrieved 4 March 2017.
  27. Transplant Support- Lung, Heart/Lung, Heart MSN groups
  28. Mortensen SP, Dawson EA, Yoshiga CC, Dalsgaard MK, Damsgaard R, Secher NH, González-Alonso J, et al. (July 2005). "Limitations to systemic and locomotor limb muscle oxygen delivery and uptake during maximal exercise in humans". The Journal of Physiology. 566 (Pt 1): 273–85. doi:10.1113/jphysiol.2005.086025. PMC   1464731 . PMID   15860533.
  29. "Blood gas and Saturation measurements". 25 September 2010. Archived from the original on 25 September 2010. Retrieved 4 March 2017.
  30. "Lecture Notes-20". 2 May 1999. Archived from the original on 2 May 1999. Retrieved 4 March 2017.
  31. Martini F, et al. (2007). Anatomy and Physiology. Rex Bookstore, Inc. p. 643. ISBN   9789712348075. Archived from the original on 1 May 2016.
  32. Vander's Human Physiology reported similar numbers: 60% carried as bicarbonate, 30% bound to hemoglobin as carbaminohemoglobin, and 10% physically dissolved. Widmaier EP, Raff H, Strang KT (2003). Vander's Human Physiology (9th ed.). McGraw-Hill Education. p. 493 (ch. Respiratory physiology § Transport of carbon dioxide in blood). ISBN   978-0-07-288074-8.
  33. 1 2 Guyton and Hall Textbook of Medical Physiology . Saunders. 2015. p. 204. ISBN   978-1455770052.
  34. "Spiders: circulatory system". Encyclopædia Britannica online. Archived from the original on 12 November 2007. Retrieved 25 November 2007.
  35. Prahl. "Optical Absorption of Hemoglobin". Archived from the original on 5 January 2002. Retrieved 30 December 2012.
  36. Kienle A, Lilge L, Vitkin IA, Patterson MS, Wilson BC, Hibst R, Steiner R (March 1996). "Why do veins appear blue? A new look at an old question" (PDF). Applied Optics. 35 (7): 1151. Bibcode:1996ApOpt..35.1151K. doi:10.1364/AO.35.001151. PMID   21085227. Archived from the original (PDF) on 10 February 2012.
  37. Austin CC, Perkins SL (August 2006). "Parasites in a biodiversity hotspot: a survey of hematozoa and a molecular phylogenetic analysis of Plasmodium in New Guinea skinks". The Journal of Parasitology. 92 (4): 770–7. doi:10.1645/GE-693R.1. PMID   16995395. S2CID   1937837. Archived from the original on 26 April 2023. Retrieved 16 November 2021.
  38. "Blood – The Human heart". The Franklin Institute. Archived from the original on 5 March 2009. Retrieved 19 March 2009.
  39. "The Role of Red Blood Cells in Anemia". Archived from the original on 18 May 2017. Retrieved 22 May 2017.
  40. Blumenthal I (June 2001). "Carbon monoxide poisoning". Journal of the Royal Society of Medicine. 94 (6): 270–2. doi:10.1177/014107680109400604. PMC   1281520 . PMID   11387414.
  41. "blood" . Oxford English Dictionary (Online ed.). Oxford University Press.(Subscription or participating institution membership required.)
  42. Hart GD (December 2001). "Descriptions of blood and blood disorders before the advent of laboratory studies" (PDF). British Journal of Haematology. 115 (4): 719–28. doi:10.1046/j.1365-2141.2001.03130.x. PMID   11843802. S2CID   10602937. Archived from the original (PDF) on 8 July 2011.
  43. "History of Blood Transfusion | American Red Cross". redcrossblood.org. Archived from the original on 4 February 2016. Retrieved 21 March 2021.
  44. Lawlor R (1991). Voices of the first day: awakening in the Aboriginal dreamtime. Rochester, VT: Inner Traditions International. pp. 102–103. ISBN   978-0-89281-355-1.
  45. Brittain, Robert P. (1965). "Cruentation: In Legal Medicine and in Literature". Medical History. 9 (1): 82–88. doi:10.1017/S0025727300030179. ISSN   0025-7273. PMC   1033446 . PMID   14252331.
  46. Koshering Meat. Archived 16 December 2013 at the Wayback Machine Chabad.org.
  47. Removing the Blood. Archived 16 December 2013 at the Wayback Machine Chabad.org.
  48. Citron, R. Aryeh. All About Kosher Fish. Archived 16 December 2013 at the Wayback Machine Chabad.org.
  49. Schneerson, R. Menachem M. Igrot Kodesh, vol. vii, p. 270.
  50. The Watchtower 15 June 2004, p. 22, "Be Guided by the Living God"
  51. Kato, Sanae; Matsui, Takashi; Gatsogiannis, Christos; Tanaka, Yoshikazu (April 2018). "Molluscan hemocyanin: structure, evolution, and physiology". Biophysical Reviews. 10 (2): 191–202. doi:10.1007/s12551-017-0349-4. ISSN   1867-2450. PMC   5899709 . PMID   29235083.
  52. "Nostalgia" Artwork in blood Archived 8 January 2009 at the Wayback Machine