Platelets and Clotting: Thrombocytes and Clotting, Smallest cellular component of blood
Home Eyes EARS MOUTH NOSE SKIN

Circulatory System
Blood INTRODUCTION ROLE OF BLOOD COMPOSITION OF BLOOD Plasma Red Blood Cells Blood Type White Blood Cells Platelets and Clotting PRODUCTION AND ELIMINATION OF BLOOD CELLS Red Blood Cell Diseases White Blood Cell Diseases Coagulation Diseases BLOOD BANKS Blood Transfusion Blood Count Blood donation and registry Blood gas analysis Blood sugar tests Blood typing and crossmatching Blood urea nitrogen test Blood-viscosity reducing drugs Blood Culture Blood Clot in the Legs Causes Blood Clot in the Legs Symptoms Blood Clot in the Legs

COMPONENTS OF THE CIRCULATORY SYSTEM OPERATION AND FUNCTION Systemic Circulation Pulmonary Circulation Additional Functions Blood Pressure
Digestive system Esophagus Gall bladder Large intestine Lips, cheeks and palate Salivary glands Serous membranes Small intestine Stomach Tunics
Teeth Tongue Digestive Process in Mouth Sleep Right Mouth Guard
LIVER LIVER DISEASES FUNCTIONS OF THE LIVER STRUCTURE OF THE LIVER
Endocrine system Glandular Structure Gonads Hormones Pancreas Parathyroid Glands Pineal Gland Pituitary Gland Pituitary Hormones Thymus Thyroid Gland
Respiratory system



Platelets and Clotting



Platelets and Clotting: Thrombocytes and Clotting, Smallest cellular component of blood

 Thrombocytes, or platelets, are the smallest cellular component of blood. They circulate inactivated, about 250,000 per cubic mm of blood, until they come into contact with a damaged blood vessel. At this point, the platelets form a clump, adhering to each other and to the blood vessel wall. They secrete chemicals that alter a blood-borne protein, fibrinogen, so that it forms a mesh of fibers at the damage site. A clot forms when platelets and red and white blood cells become trapped in the fibers. Blood clotting begins within seconds of injury. The same process can produce unwelcome clots in undamaged blood vessels.

 The smallest cells in the blood are the platelets, which are designed for a single purpose—to begin the process of coagulation, or forming a clot, whenever a blood vessel is broken. As soon as an artery or vein is injured, the platelets in the area of the injury begin to clump together and stick to the edges of the cut. They also release messengers into the blood that perform a variety of functions: constricting the blood vessels to reduce bleeding, attracting more platelets to the area to enlarge the platelet plug, and initiating the work of plasma-based clotting factors, such as fibrinogen. Through a complex mechanism involving many steps and many clotting factors, the plasma protein fibrinogen is transformed into long, sticky threads of fibrin. Together, the platelets and the fibrin create an intertwined meshwork that forms a stable clot. This self-sealing aspect of the blood is crucial to survival.



auuuu.org ©2016.