February 22, 2024

Mechanisms of blood coagulation

Mechanisms of blood coagulation

The mechanism of coagulation involves a complex series of interactions between blood cells, clotting factors, and the endothelium (the inner lining of blood vessels). There are two main pathways involved in the coagulation process: the extrinsic pathway and the intrinsic pathway. These pathways eventually converge to form the common pathway, which leads to the formation of a fibrin clot.

Extrinsic pathway:

  1. Tissue factor is released from damaged endothelial cells or from tissue outside the blood vessel.
  2. Tissue factor binds to and activates factor VII.
  3. Activated factor VII, along with factor III (tissue factor), activates factor X.

Intrinsic pathway:

  1. Factor XII, also known as Hageman factor, is activated by contact with exposed collagen and other substances in the blood.
  2. Activated factor XII activates factor XI.
  3. Activated factor XI activates factor IX.
  4. Activated factor IX, along with factor VIII, calcium ions, and phospholipids, activates factor X.

Common pathway:

  1. Activated factor X combines with factor V, calcium ions, and phospholipids to form prothrombinase.
  2. Prothrombinase converts prothrombin into thrombin.
  3. Thrombin then converts fibrinogen into fibrin.
  4. Fibrin strands combine to form a fibrin clot, which stabilizes the platelet plug and prevents further bleeding.

The coagulation process is carefully regulated to prevent excessive clotting, which can lead to thrombosis or blockage of blood vessels. Anticoagulant proteins like antithrombin, protein C, and protein S help to balance the coagulation process and prevent unwanted clotting.

Disorders of coagulation can lead to bleeding disorders, such as hemophilia, or clotting disorders, such as thrombophilia. These conditions can increase the risk of bleeding or thrombosis and may require medical intervention to manage.

First Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise

F Y B Pharm Sem-IF Y B Pharm Sem-II
BP101T Human Anatomy and Physiology I TheoryBP201T Human Anatomy and Physiology II – Theory
BP102T Pharmaceutical Analysis I TheoryBP202T Pharmaceutical Organic Chemistry I Theory
BP103T Pharmaceutics I TheoryBP203T Biochemistry – Theory
BP104T Pharmaceutical Inorganic Chemistry TheoryBP204T Pathophysiology – Theory
BP105T Communication skills TheoryBP205T Computer Applications in Pharmacy Theory
BP106RBT Remedial BiologyBP206T Environmental sciences – Theory
BP106RMT Remedial Mathematics TheoryBP207P Human Anatomy and Physiology II Practical
BP107P Human Anatomy and Physiology PracticalBP208P Pharmaceutical Organic Chemistry I Practical
BP108P Pharmaceutical Analysis I PracticalBP209P Biochemistry Practical
BP109P Pharmaceutics I PracticalBP210P Computer Applications in Pharmacy Practical
BP110P Pharmaceutical Inorganic Chemistry Practical
BP111P Communication skills Practical
BP112RBP Remedial Biology Practical

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