What is the function of the thrombocytes?
A.
Defend against infection
B.
Transport respiratory gases.
C.
Form connective tissue.
D.
Play a role in blood clotting.
The Correct answer and Explanation is:
The correct answer is:
D. Play a role in blood clotting.
Explanation:
Thrombocytes, commonly known as platelets, are a crucial component of the blood involved in the process of hemostasis, which is the prevention of blood loss from damaged vessels. They are small, disc-shaped cell fragments derived from the cytoplasm of megakaryocytes in the bone marrow. Unlike other blood cells, thrombocytes do not have a nucleus, but they contain granules that are essential for their function.
When a blood vessel is injured, thrombocytes are among the first responders to the site of damage. Their primary role is to adhere to the exposed collagen fibers in the vessel wall, a process facilitated by surface receptors and adhesive proteins such as von Willebrand factor. Once attached, platelets become activated and release various chemicals stored in their granules. These chemicals include clotting factors, such as serotonin, adenosine diphosphate (ADP), and thromboxane A2, which help to further recruit and activate additional platelets to the site of injury.
Activated platelets also change shape, becoming more spherical with projections, which enhances their ability to interact with other platelets and form a temporary “platelet plug” that covers the wound. This plug acts as a barrier to prevent further blood loss and provides a foundation for the subsequent formation of a stable blood clot.
The formation of the stable clot involves a complex cascade of enzymatic reactions known as the coagulation cascade, leading to the conversion of fibrinogen, a soluble plasma protein, into fibrin threads that weave through the platelet plug, solidifying and reinforcing it into a durable blood clot.
Therefore, thrombocytes are integral to hemostasis by initiating the clotting process, aggregating to form a plug, and supporting the formation of a stable clot to prevent excessive bleeding and facilitate tissue repair. Without adequate platelet function, even minor injuries could result in significant bleeding and impaired wound healing.