Where are most clotting factors synthesized in the body?
a. Several key blood clotting factors are synthesized in the liver. b. EPO is secreted by the bone marrow c. Prothrombin is synthesized by the kidney d. The spleen utilizes vitamin K to synthesize prothrombin.
What are the 13 blood coagulation factors?
The following are coagulation factors and their common names: Factor I – fibrinogen. Factor II – prothrombin. Factor V – labile factor or proaccelerin. Factor VI – unassigned. Factor VII – stable factor or proconvertin. How many types of clotting factors are there?
How many factors are involved in blood clotting?
The following factors increase your risk of developing a blood clot:
- Obesity
- Pregnancy
- Immobility (including prolonged inactivity, long trips by plane or car)
- Smoking
- Oral contraceptives
- Certain cancers
- Trauma
- Certain surgeries
- Age (increased risk for people over age 60)
- A family history of blood clots
What are the names of the clotting factors?
These include:
- Heavy bleeding after an injury
- Easy bruising
- Swelling
- Pain and stiffness
- An unexplained blood clot. In some bleeding disorders, the blood clots too much, rather than too little. ...
What produces blood clotting factors?
The coagulation factors (proteins) are manufactured by the liver. Ionized calcium ( Ca++ ) is available in the blood and from intracellular sources. Phospholipids are prominent components of cellular and platelet membranes. They provide a surface upon which the chemical reactions of coagulation can take place.
Are clotting factors made in the liver?
Within the liver, hepatocytes are involved in the synthesis of most blood coagulation factors, such as fibrinogen, prothrombin, factor V, VII, IX, X, XI, XII, as well as protein C and S, and antithrombin, whereas liver sinusoidal endothelial cells produce factor VIII and von Willebrand factor.
Where is factor VIII produced?
the liverCoagulation factor VIII is made chiefly by cells in the liver. This protein circulates in the bloodstream in an inactive form, bound to another molecule called von Willebrand factor, until an injury that damages blood vessels occurs.
Is tissue factor made in the liver?
The liver is the primary site of synthesis of nearly all coagulation factors, along with several proteins involved in fibrinolysis and anticoagulation.
Which factor activates fibrinogen?
Factor IIa (thrombin) goes on to activate fibrinogen into fibrin. Thrombin also goes on to activate other factors in the intrinsic pathway (factor XI) as well as cofactors V and VIII and factor XIII. Fibrin subunits come together to form fibrin strands, and factor XIII acts on fibrin strands to form a fibrin mesh.
What is the purpose of coagulation pathway?
The purpose is to ultimately stabilize the platelet plug with a fibrin mesh. [1][2][3] Function. The function of the coagulation pathway is to keep hemostasis, which is the blockage of a bleeding or hemorrhage. Primary hemostasis is an aggregation of platelets forming a plug at the damaged site of exposed endothelial cells.
What is the primary hemostasis?
Primary hemostasis is an aggregation of platelets forming a plug at the damaged site of exposed endothelial cells. Secondary hemostasis includes the two main coagulation pathways, intrinsic and extrinsic, that meet up at a point to form the common pathway. The common pathway ultimately activates fibrinogen into fibrin.
What is the role of the liver in the formation of factors?
The liver is responsible for the formation of factors I, II, V, VII, VIII, IX, X, XI, XIII, and protein C and S. Factor VII is created by the vascular endothelium. Pathology to the liver can cause lack of coagulation factors and lead to hemorrhage. A decrease in coagulation factors typically means severe liver damage.
What is the process of activating factor XA?
The process of activating factor Xa is a complicated reaction. Tenase is the complex that cleaves factor X into factor Xa. Tenase has two forms: extrinsic, consisting of factor VII, factor III (tissue factor) and Ca2+, or intrinsic, made up of cofactor factor VIII, factor IXA, a phospholipid, and Ca2+.
What is the INR of factor VII?
Factor VII has the shortest half-life, leading to elevated PT first in liver disease. INR can be greater than 6.5 (normal is close to 1.0). Coagulopathy in liver disease is treated with fresh frozen plasma.
What is the role of factor XIIA in endothelial damage?
Endothelial collagen is only exposed when endothelial damage occurs. Factor XIIA acts as a catalyst to activate factor XI to Factor XIA.
What are the factors that make blood clots?
The following are the clotting factors involved in the process of blood clot formation. Factor I: Clotting factor I is also known as fibrinogen. It is synthesized by the liver. Fibrinogen is the last enzyme to be activated in the process of clot formation. It is downstream of both intrinsic and extrinsic pathways.
Which pathway is involved in the formation of blood clots?
This pathway plays a major role in the formation of blood clots. Intrinsic pathway: The intrinsic pathway, also known as contact activation pathway, is stimulated by activation of a specific clotting factor (factor XII) when it comes in contact with exposed collagen.
What is the final pathway for clot formation?
Final common pathway: Both intrinsic and extrinsic pathways finally converge to activate a protein known as prothrombin. Activated prothrombin, also called thrombin, then activates fibrinogen to form the fibrin blood clot. Also read on menstrual clots.
What are the two pathways of clotting factor activation?
The cascade of clotting factor activation is traditionally viewed as being divided into two separate pathways: intrinsic pathway and extrinsic pathway.
What is the process of fibrin clot formation?
The process of fibrin clot formation also requires a cascade of enzyme activations. These enzymes are known as clotting factors, and are normally present in the blood in inactive forms. When the coagulation process begins, the clotting factors start getting activated in a linear fashion by one another.
What is the clotting factor of fibrin?
The long strands of fibrin form an interconnected meshwork that constitutes the clot. Factor II: Clotting factor II is also known as prothrombin. Like fibrinogen, prothrombin is also synthesized by the liver. Clotting factor II is a step above the clotting factor I in the cascade.
What is the process of clotting blood?
The clotting of blood is a very complex process, which is orchestrated by aggregation and activation of different chemicals, cells and components of blood. Disorders at any step in the clotting mechanism could lead to bleeding (hemorrhagic) disorders or abnormal clot formations (thrombosis). Either of these conditions could be lethal.
Which pathway is clotting initiated by?
The division of coagulation in two pathways is arbitrary, originating from laboratory tests in which clotting times were measured either after the clotting was initiated by glass, the intrinsic pathway; or clotting was initiated by thromboplastin (a mix of tissue factor and phospholipids), the extrinsic pathway.
What is the process of blood clotting?
For other uses, see Coagulation (disambiguation). Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair.
What is the term for platelets that form a plug at the site of injury?
Platelets immediately form a plug at the site of injury; this is called primary hemostasis. Secondary hemostasis occurs simultaneously: additional coagulation (clotting) factors beyond factor VII ( listed below) respond in a cascade to form fibrin strands, which strengthen the platelet plug.
What are the tests for coagulation?
Numerous tests are used to assess the function of the coagulation system: 1 Common: aPTT, PT (also used to determine INR ), fibrinogen testing (often by the Clauss method ), platelet count, platelet function testing (often by PFA-100 ), thrombodynamics test. 2 Other: TCT, bleeding time, mixing test (whether an abnormality corrects if the patient's plasma is mixed with normal plasma), coagulation factor assays, antiphospholipid antibodies, D-dimer, genetic tests (e.g. factor V Leiden, prothrombin mutation G20210A), dilute Russell's viper venom time (dRVVT), miscellaneous platelet function tests, thromboelastography (TEG or Sonoclot), euglobulin lysis time (ELT).
What is the role of calcium in coagulation?
Calcium mediates the binding of the complexes via the terminal gamma-carboxy residues on FXa and FIXa to the phospholipid surfaces expressed by platelets, as well as procoagulant microparticles or microvesicles shed from them. Calcium is also required at other points in the coagulation cascade.
What is the most commonly used anticoagulant?
Of the anticoagulants, warfarin (and related coumarins) and heparin are the most commonly used. Warfarin affects the vitamin K-dependent clotting factors (II, VII, IX, X) and protein C and protein S, whereas heparin and related compounds increase the action of antithrombin on thrombin and factor Xa. A newer class of drugs, the direct thrombin inhibitors, is under development; some members are already in clinical use (such as lepirudin ). Also in clinical use are other small molecular compounds that interfere directly with the enzymatic action of particular coagulation factors (the directly acting oral anticoagulants: dabigatran, rivaroxaban, apixaban, and edoxaban ).
What is the protein that is found on the surface of platelets?
Coagulation defects may cause hemorrhage or thrombosis, and occasionally both, depending on the nature of the defect. The GP1b-IX receptor complex. This protein receptor complex is found on the surface of platelets, and in conjunction with GPV allows for platelets to adhere to the site of injury.
How are recombinant clotting factor products produced?
Recombinant blood: Recombinant clotting factors are made in a laboratory and do not contain human or animal factors. The lab has the sequence of dna that creates the factor and uses that dna to create the clottoig factor.
What is a recombinant clotting factor product?
Ultra High Tech!: These products (which are used to treat a wide variety of bleeding disorders like hemophilia, and von willebrand's disease) are made either by being completely free of human plasma derivative; or use a pasteurized form that is very safe.
Overview
Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The mechanism of coagulation involves activation, adhesion and aggregation of platelets, as well as deposition and maturation of fibrin.
Physiology
When the endothelium is damaged, the normally isolated underlying collagen is exposed to circulating platelets, which bind directly to collagen with collagen-specific glycoprotein Ia/IIa surface receptors. This adhesion is strengthened further by von Willebrand factor (vWF), which is released from the endothelium and from platelets; vWF forms additional links between the platelets' glycoprot…
Assessment
Numerous tests are used to assess the function of the coagulation system:
• Common: aPTT, PT (also used to determine INR), fibrinogen testing (often by the Clauss method), platelet count, platelet function testing (often by PFA-100), thrombodynamics test.
• Other: TCT, bleeding time, mixing test (whether an abnormality corrects if the patient's plasma is mixed with normal plasma), coagulation factor assays, antiphospholipid antibodies, D-dimer, genetic tests (e…
Role in disease
Coagulation defects may cause hemorrhage or thrombosis, and occasionally both, depending on the nature of the defect.
Platelet disorders are either congenital or acquired. Examples of congenital platelet disorders are Glanzmann's thrombasthenia, Bernard–Soulier syndrome (abnormal glycoprotein Ib-IX-V complex), gray platelet syndrome (deficient alph…
Pharmacology
The use of adsorbent chemicals, such as zeolites, and other hemostatic agents are also used for sealing severe injuries quickly (such as in traumatic bleeding secondary to gunshot wounds). Thrombin and fibrin glue are used surgically to treat bleeding and to thrombose aneurysms. Hemostatic Powder Spray TC-325 is used to treated gastrointestinal bleeding.
History
Theories on the coagulation of blood have existed since antiquity. Physiologist Johannes Müller (1801–1858) described fibrin, the substance of a thrombus. Its soluble precursor, fibrinogen, was thus named by Rudolf Virchow (1821–1902), and isolated chemically by Prosper Sylvain Denis (1799–1863). Alexander Schmidt suggested that the conversion from fibrinogen to fibrin is the result of an enzymatic process, and labeled the hypothetical enzyme "thrombin" and its precursor "
Other species
All mammals have an extremely closely related blood coagulation process, using a combined cellular and serine protease process. In fact, it is possible for any mammalian coagulation factor to "cleave" its equivalent target in any other mammal. The only non-mammalian animal known to use serine proteases for blood coagulation is the horseshoe crab.
See also
• Agglutination (biology)
• Post-vaccination embolic and thrombotic events