File Name: calcium and blood coagulation .zip
- Overview of the coagulation system
- The Role of Calcium in Coagulation and Anticoagulation
- CALCIUM AND BLOOD COAGULATION
Overview of the coagulation system
Coagulation clotting is the process by which blood changes from a liquid to a gel, forming a 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 along with deposition and maturation of fibrin. Disorders of coagulation can result in bleeding hemorrhage or bruising or obstructive clotting thrombosis. The coagulation cascade of secondary hemostasis has two initial pathways which lead to fibrin formation:.
The enormous literature on the phenomenon of the clotting of blood attests vigorous investigative activity. William Hewson 1 wrote in of his observation that coagulation could be influenced by salts of various kinds. During the middle years of the nineteenth century active investigation resulted in the discovery that serum contained an organic substance, which could also be extracted from blood clots, that had the power of initiating the coagulation of blood and of various ordinarily incoagulable body fluids. Alexander Schmidt showed in that inorganic salts had an essential part in the process of clotting. Most workers accept the requirement of calcium as constituting a link in the chain of events ending in the formation of the fibrin clot but at present there.
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. Coagulation begins almost instantly after an injury to the endothelium lining a blood vessel. Exposure of blood to the subendothelial space initiates two processes: changes in platelets, and the exposure of subendothelial tissue factor to plasma factor VII , which ultimately leads to cross-linked fibrin formation.
During the past quarter century perhaps no single phenomenon has attracted so much attention in biology and medicine as blood clotting. It plays a role in numerous clinical conditions where it was not taken into account previously. Knowledge of the basic mechanisms recently passed through a tumulous stage of growth, but is now delineated in terms of simple enzymology. Most of the components have been obtained in purified form. There are three main events: the formation of autoprothrombin C F-Xa, thrombokinase , the formation of thrombin, and the formation of fibrin.
Coagulation is a dynamic process and the understanding of the blood coagulation system has evolved over the recent years in anaesthetic practice. Although the traditional classification of the coagulation system into extrinsic and intrinsic pathway is still valid, the newer insights into coagulation provide more authentic description of the same. Normal coagulation pathway represents a balance between the pro coagulant pathway that is responsible for clot formation and the mechanisms that inhibit the same beyond the injury site. Imbalance of the coagulation system may occur in the perioperative period or during critical illness, which may be secondary to numerous factors leading to a tendency of either thrombosis or bleeding. Since the balance of the coagulation system may tilt towards bleeding and thrombosis in many situations, it is mandatory for the clinicians to understand physiologic basis of haemostasis in order to diagnose and manage the abnormalities of the coagulation process and to interpret the diagnostic tests done for the same.
appears to be a function of the diffusible calcium and is not accompanied by blood coagulation anom- alies (). The necessity of calcium for blood clotting.
The Role of Calcium in Coagulation and Anticoagulation
Я не выйду за тебя замуж! - Она расхохоталась и стукнула его подушкой. - До тех пор, пока ты не объяснишь, что такое без воска. Ты сводишь меня с ума.
CALCIUM AND BLOOD COAGULATION
Беккер прекрасно помнил все, что произошло, и опустил глаза, думая увидеть перед собой своего убийцу. Но того человека в очках нигде не. Были другие люди.
Я никуда не спешу. Стратмор сокрушенно вздохнул и начал мерить шагами комнату. - Очевидно, когда Танкадо умер, рядом находились свидетели. Согласно словам офицера, который отвел Дэвида в морг, некий канадский турист сегодня утром в панике позвонил в полицию и сказал, что у одного японца в парке случился сердечный приступ.
Если честно… - Он вытянул шею и подвигал головой влево и вправо. - Мне не помешала бы еще одна подушка, если вас это не затруднит. - Нисколько. - Беккер взял подушку с соседней койки и помог Клушару устроиться поудобнее. Старик умиротворенно вздохнул.
Вы хотите отправить его домой. - Нет. Пусть остается.