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57-499: 2811 14723 ENSG00000185245 ENSMUSG00000050675 P07359 O35930 NM_000173 NM_010326 NP_000164 NP_034456 Glycoprotein Ib (GP Ib) is a platelet surface membrane glycoprotein receptor composed of a heterodimer, an alpha chain and a beta chain, that are linked by disulfide bonds. The Gp Ib functions as a receptor for von Willebrand factor (VWF). The complete receptor complex includes noncovalent association of

114-732: A bleeding diathesis of the skin and mucous membranes, causing nosebleeds , menorrhagia , and gastrointestinal bleeding . The point at which the mutation occurs determines the severity of the bleeding diathesis. There are three types (I, II and III), and type II is further divided in several subtypes. Treatment depends on the nature of the abnormality and the severity of the symptoms. Most cases of vWD are hereditary, but abnormalities of VWF may be acquired; aortic valve stenosis , for instance, has been linked to vWD type IIA, causing gastrointestinal bleeding - an association known as Heyde's syndrome . In thrombotic thrombocytopenic purpura (TTP) and hemolytic–uremic syndrome (HUS), ADAMTS13 either

171-724: 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. Many forms of medication (from antibiotics to chemotherapy ) are administered intravenously, as they are not readily or adequately absorbed by

228-574: A blood transfusion, because the metabolism of transfused red blood cells does not restart immediately after a transfusion. 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. English blood ( Old English blod ) derives from Germanic and has cognates with

285-463: A number of specific domains with a specific function; elements of note are: Monomers are subsequently N-glycosylated , arranged into dimers in the endoplasmic reticulum and into multimers in the Golgi apparatus by crosslinking of cysteine residues via disulfide bonds . With respect to the glycosylation, VWF is one of only a few proteins that carry ABO blood group system antigens. VWFs coming out of

342-426: A pH below 7.35 is too acidic , whereas blood pH above 7.45 is too basic. A pH below 6.9 or above 7.8 is usually lethal. Blood pH, partial pressure of oxygen (pO 2 ) , partial pressure of carbon dioxide (pCO 2 ) , and bicarbonate (HCO 3 ) are carefully regulated by a number of homeostatic mechanisms , which exert their influence principally through the respiratory system and the urinary system to control

399-537: 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. 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

456-423: 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

513-469: Is a blood glycoprotein that promotes hemostasis , specifically, platelet adhesion . It is deficient and/or defective in von Willebrand disease and is involved in many other diseases, including thrombotic thrombocytopenic purpura , Heyde's syndrome , and possibly hemolytic–uremic syndrome . Increased plasma levels in many cardiovascular, neoplastic, metabolic (e.g. diabetes), and connective tissue diseases are presumed to arise from adverse changes to

570-461: Is arterial or venous blood). Most of it (about 70%) is converted to bicarbonate ions HCO − 3 by the enzyme carbonic anhydrase in the red blood cells by the reaction CO 2 + H 2 O → H 2 CO 3 → H + HCO − 3 ; about 7% is dissolved in the plasma; and about 23% is bound to hemoglobin as carbamino compounds. Hemoglobin, the main oxygen-carrying molecule in red blood cells, carries both oxygen and carbon dioxide. However,

627-418: 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

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684-405: Is binding to other proteins, in particular factor VIII , and it is important in platelet adhesion to wound sites. It is not an enzyme and, thus, has no catalytic activity. VWF binds to a number of cells and molecules. The most important ones are: VWF plays a major role in blood coagulation. Therefore, VWF deficiency or dysfunction (von Willebrand disease) leads to a bleeding tendency, which

741-440: 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,

798-407: 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

855-688: Is composed of blood cells suspended in blood plasma . Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), 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). The most abundant cells are red blood cells. These contain hemoglobin , which facilitates oxygen transport by reversibly binding to it, increasing its solubility. 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

912-480: Is dangerous to health, and severe hypoxia (saturations less than 30%) may be rapidly fatal. 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. CO 2 is carried in blood in three different ways. (The exact percentages vary depending whether it

969-499: Is deficient or has been inhibited by antibodies directed at the enzyme. This leads to decreased breakdown of the ultra-large multimers of VWF and microangiopathic hemolytic anemia with deposition of fibrin and platelets in small vessels, and capillary necrosis. In TTP, the organ most obviously affected is the brain; in HUS, the kidney. Higher levels of VWF are more common among people that have had ischemic stroke (from blood-clotting) for

1026-426: 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

1083-436: 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. Blood for transfusion is obtained from human donors by blood donation and stored in

1140-461: 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. Blood circulation transports heat throughout the body, and adjustments to this flow are an important part of thermoregulation . Increasing blood flow to

1197-561: 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 CO 2 or a lower pH will cause offloading of oxygen from hemoglobin, which is known as the Bohr effect . 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. In mammals, blood

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1254-408: Is most apparent in tissues having high blood flow shear in narrow vessels. From studies it appears that VWF uncoils under these circumstances, decelerating passing platelets. Recent research also suggests that von Willebrand Factor is involved in the formation of blood vessels themselves , which would explain why some people with von Willebrand disease develop vascular malformations (predominantly in

1311-445: Is named after Erik Adolf von Willebrand , a Finnish physician who in 1926 first described a hereditary bleeding disorder in families from Åland . Although von Willebrand did not identify the definite cause, he distinguished von Willebrand disease (vWD) from hemophilia and other forms of bleeding diathesis . In the 1950s, vWD was shown to be caused by a plasma factor deficiency (instead of being caused by platelet disorders), and, in

1368-511: Is oxygenated and dark red when it is deoxygenated . 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 , given its origin in the bones and the presence of potential molecular fibers in the form of fibrinogen . Blood performs many important functions within

1425-488: 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

1482-529: The acid–base balance and respiration, which is called compensation. 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. 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: Blood

1539-405: 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

1596-401: The digestive tract ) that can bleed excessively . The biological breakdown ( catabolism ) of VWF is largely mediated by the enzyme ADAMTS13 (acronym of " a d isintegrin-like a nd m etalloprotease with t hrombo s pondin type 1 motif no. 13 "). It is a metalloproteinase that cleaves VWF between tyrosine at position 842 and methionine at position 843 (or 1605–1606 of the gene) in

1653-459: The endothelium , and may predict an increased risk of thrombosis . VWF is a large multimeric glycoprotein present in blood plasma and produced constitutively as ultra-large VWF in endothelium (in the Weibel–Palade bodies ), megakaryocytes (α-granules of platelets ), and subendothelial connective tissue . The basic VWF monomer is a 2050- amino acid protein. Every monomer contains

1710-428: 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. Hemoglobin is the principal determinant of the color of blood ( hemochrome ). Each molecule has four heme groups, and their interaction with various molecules alters

1767-482: 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

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1824-479: The urine . About 98.5% 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 O 2 per gram hemoglobin, which increases

1881-471: The 1970s, the VWF protein was purified. Harvey J. Weiss and coworkers developed a quantitative assay for VWF function that remains a mainstay of laboratory evaluation for VWD to this day. Von Willebrand Factor has been shown to interact with Collagen, type I, alpha 1 . Recently, It has been reported that the cooperation and interactions within the von Willebrand Factors enhances the adsorption probability in

1938-539: The A2 domain. This breaks down the multimers into smaller units, which are degraded by other peptidases . The half-life of vWF in human plasma is around 16 hours; glycosylation variation on vWF molecules from different individuals result in a larger range of 4.2 to 26 hours. Liver cells as well as macrophages take up vWF for clearance via ASGPRs and LRP1 . SIGLEC5 and CLEC4M also recognize vWF. Hereditary or acquired defects of VWF lead to von Willebrand disease (vWD),

1995-507: The CO 2 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 CO 2 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

2052-478: The Golgi are packaged into storage organelles, Weibel-Palade bodies (WPBs) in endothelial cells and α-granules in platelets. Multimers of VWF can be extremely large, >20,000 kDa , and consist of over 80 subunits of 250 kDa each. Only the large multimers are functional. Some cleavage products that result from VWF production are also secreted but probably serve no function. Von Willebrand Factor's primary function

2109-1028: The OS-1 peptide. The OS-1 peptide prevents binding of GPIb alpha to the VWF A1 domain. The co-crystal structure of GPIb alpha and OS-1 has been reported. This article incorporates text from the United States National Library of Medicine , which is in the public domain . This membrane protein –related article is a stub . You can help Misplaced Pages by expanding it . Von Willebrand factor 1AO3 , 1ATZ , 1AUQ , 1FE8 , 1FNS , 1IJB , 1IJK , 1M10 , 1OAK , 1U0N , 2ADF , 3GXB , 3HXO , 3HXQ , 3PPV , 3PPW , 3PPX , 3PPY , 3ZQK , 4DMU , 1UEX , 2MHP , 2MHQ , 4C29 , 4C2A , 4C2B , 4NT5 , 5BV8 7450 22371 ENSG00000110799 ENSMUSG00000001930 P04275 Q8CIZ8 NM_000552 NM_011708 NP_000543 NP_035838 Von Willebrand factor ( VWF ) ( German: [fɔn ˈvɪləbʁant] )

2166-483: The actual color of the venous blood. Skinks in the genus Prasinohaema have green blood due to a buildup of the waste product biliverdin . 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

2223-551: The alpha and beta subunits with platelet glycoprotein IX and platelet glycoprotein V to form the glycoprotein Ib-IX-V complex . Binding of the GP Ib-IX-V complex to VWF facilitates initial platelet adhesion to vascular subendothelium after vascular injury, and also initiates signaling events within the platelet that lead to enhanced platelet activation, thrombosis, and hemostasis. This gene encodes

2280-635: The alpha subunit. Several polymorphisms and mutations have been described in this gene, some of which are the cause of Bernard–Soulier syndromes and platelet-type von Willebrand disease . GP1BA has been shown to interact with YWHAZ and FLNB . CCP-224, a short PEG-conjugated form of the cyclic peptide OS-1, binds to human GPIb alpha with high affinity and can prevents neutrophil-platelet aggregation in Sickle Cell Disease. In vivo, platelet-mediated thrombus formation can be greatly reduced in arterioles of mice, injured by laser, following an infusion of

2337-473: 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 . Blood pH is regulated to stay within the narrow range of 7.35 to 7.45, making it slightly basic (compensation). Extra-cellular fluid in blood that has

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2394-475: The body, including: Blood accounts for 7% of the human body weight, with an average density around 1060 kg/m , very close to pure water's density of 1000 kg/m . The average adult has a blood volume of roughly 5 litres (11 US pt) or 1.3 gallons, 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

2451-422: The cell fragments called platelets 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 . One microliter of blood contains: 45 ± 7 (38–52%) for males 42 ± 5 (37–47%) for females Oxygenated: 98–99% Deoxygenated: 75% About 55% of blood

2508-413: 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, CaCl 2 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

2565-431: 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. Blood in carbon monoxide poisoning

2622-401: The first time. Occurrence is not affected by ADAMTS13, and the only significant genetic factor is the person's blood group. High plasma VWF levels were found to be an independent predictor of major bleeding in anticoagulated atrial fibrillation patients. VWF is a marker of endothelial dysfunction , and is consistently elevated in atrial fibrillation, associated with adverse outcomes. VWF

2679-530: The lungs is still roughly 75% (70 to 78%) 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. Oxygen saturation this low is considered dangerous in an individual at rest (for instance, during surgery under anesthesia). Sustained hypoxia (oxygenation less than 90%),

2736-407: 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. 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 ,

2793-464: 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"). In general, Greek thinkers believed that blood

2850-419: 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 to the body. In a healthy adult at rest, oxygen consumption is approximately 200–250 ml/min, and deoxygenated blood returning to

2907-481: The primary haemostasis. Such cooperation is proven by calculating the adsorption probability of flowing VWF once it crosses another adsorbed one. Such cooperation is held within a wide range of shear rates. Blood 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. Blood

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2964-505: 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 . The proteinaceous component of blood (including clotting proteins)

3021-422: The second and the third most supplied organs, with 1100 ml/min and ~700 ml/min, respectively. 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. The restriction of blood flow can also be used in specialized tissues to cause engorgement, resulting in an erection of that tissue; examples are

3078-489: 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 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

3135-443: The total blood oxygen capacity seventyfold, compared to if oxygen solely were carried by its solubility of 0.03 ml O 2 per liter blood per mm Hg partial pressure of oxygen (about 100 mm Hg in arteries). 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

3192-489: 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. The first non-direct transfusion was performed on 27 March 1914. The Rhesus factor was discovered in 1937. Due to its importance to life, blood

3249-464: Was made from food. Plato and Aristotle are two important sources of evidence for this view, but it dates back to Homer's Iliad . Plato thinks that fire in our bellies transform food into blood. Plato believes that the movements of air in the body as we exhale and inhale carry the fire as it transforms our food into blood. Aristotle believed that food is concocted into blood in the heart and transformed into our body's matter. The ABO blood group system

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