Question

Which of the following statements is(are) correct?

A. Hemostasis is the process by which the body spontaneously stops bleeding and maintains blood in the fluid state within the vascular compartment

B. Hemostasis is divided into two stages: primary and secondary

C. Normal vascular endothelial cell surface is thromboresistant (or antithrombotic)

D. All of the above

Answer 1

Hemostasis is the natural process that stops blood loss when an injury occurs.Hemostasis can either be primary or secondary. Primary hemostasis refers to platelet plug formation, which forms the primary clot. Secondary hemostasis refers to the coagulation cascade, which produces a fibrin mesh to strengthen the platelet plug. Secondary hemostasis occurs simultaneously with primary hemostasis, but generally finishes after it. The coagulation factors circulate as inactive enzyme precursors, which, upon activation, take part in the series of reactions that make up the coagulation cascade. The coagulation factors are generally serine proteases (enzymes).

Vascular endothelial and smooth muscle cells actively maintain vessel wall thromboresistance by expressing several antithrombotic properties. With perturbation or injury, vascular cells express thrombogenic properties.Under normal conditions, the endothelial cell provides a nonthrombogenic surface that does not allow platelets or other blood cells to adhere and does not activate the coagulation cascade.

Thus from all the above facts we can conclude all the above statement are ture. Hence, the answer is (D)