This complex runs just beneath these membranes and is the chemical motor that literally pulls the invaginated OCS out of the interior of the platelet, like turning pants pockets inside out, creating the dendrites. This process is similar to the mechanism of contraction in a muscle cell. The entire OCS thus becomes indistinguishable from the initial platelet membrane as it forms the "fried egg". This dramatic increase in surface area comes about with neither stretching nor adding phospholipids to the platelet membrane. Platelet-coagulation factor interactions: coagulation facilitation
Platelet activation causes its membrane surface to become negatively charged. One of the signaling pathways turns on scramblase, which moves negatively charged phospholipids from the inner to the outer platelet membrane surface. These phospholipids then bind the tenase and prothrombinase complexes, two of the sites of interplay between platelets and the coagulation cascade. Calcium ions are essential for the binding of these coagulation factors. In addition to interacting with vWF and fibrin, platelets interact with thrombin, Factors X, Va, VIIa, XI, IX, and prothrombin to complete formation via the coagulation cascade. Six studies suggested platelets express tissue factor: the definitive study shows they do not. The platelets from rats were conclusively shown to express tissue factor protein and also it was proved that the rat platelets carry both the tissue factor pre-mRNA and mature mRNA. Aggregation
Aggregation begins minutes after activation, and occurs as a result of turning on the GPIIb/IIIa receptor, allowing these receptors to bind with vWF or fibrinogen. There are around 60,000 of these receptors per platelet.
The mulberry colored spot is very well known in Afro-Brazilians. In Brazil, among individuals of mixed Indigenous American and West African descent (pardo) it is called "genipapo", from its resemblance in color (bluish-gray) to an indigenous fruit of Brazil, named genipapo (a Native word adopted into Portuguese). Prevalence
Infants may be born with one or more slate grey nevus ranging from small area on the buttocks to a larger area on the back. The birthmark is prevalent among East, South, Southeast, North and Central Asian peoples, Indigenous Oceanians (chiefly Micronesians and Polynesians), certain populations in Africa, Amerindians, non-European Latin Americans and Caribbeans of mixed-race descent.They occur in around 80% of Asians, and 80% to 85% of Native American infants. Approximately 90% of Polynesians and Micronesians are born with slate grey nevus, as are about 46% of children in Latin America, where they are associated with non-European descent. These spots also appear on 5–10% of babies of full Caucasian descent; Coria del Río in Spain has a high incidence due to the presence of descendants of members of the delegation led by Hasekura Tsunenaga, the first Japanese official envoy to Spain in the early 17th century. African American babies have slate grey nevus at a frequencies of 90% to 96%.According to a 2006 study examining the Mongolian spot among newborns in the Turkish city of İzmir, it was found out that 26% of the examined babies had the condition. It was noted the prevalence rate was 20% and 31% in boys and girls, respectively.