Coagulation of Blood and Essential Substances

Coagulation of blood is a complex process that involves the formation of a clot to prevent excessive bleeding. This process is regulated by a series of steps that involve various substances. The pair of substances essential for coagulation of blood is calcium ions and platelet factors.

Calcium Ions

Calcium ions are essential for the coagulation cascade, which is a series of reactions that lead to the formation of a clot. They are required for the activation of a number of coagulation factors, including factor IX, factor X, and prothrombin. Calcium ions also play a role in the activation of platelets, which are necessary for the formation of a clot.

Platelet Factors

Platelet factors, also known as platelet-derived growth factors, are proteins that are released by activated platelets. They play a critical role in the formation of a clot by stimulating the proliferation of cells that produce fibrin, a key component of the clot. Platelet factors also promote the migration of cells to the site of injury, which helps to repair the damaged tissue.

Other Substances

Heparin is an anticoagulant that inhibits the coagulation cascade by binding to and activating antithrombin III, which in turn inhibits the activity of several coagulation factors, including thrombin. Oxalates and citrates are also anticoagulants that are commonly used in laboratory settings to prevent blood from clotting.

Conclusion

In summary, the pair of substances that is essential for coagulation of blood is calcium ions and platelet factors. These substances play a critical role in the coagulation cascade and the formation of a clot to prevent excessive bleeding. Other substances, such as heparin, oxalates, and citrates, also play a role in regulating coagulation, but they are not essential for the process.

B : calcium ions and platelet factors.