Which role is attributed to the base in the acid-base balance?

Choice A rationale:

Purpura refers to purple or red discolorations on the skin caused by bleeding underneath the skin. It is larger than petechiae and ecchymosis and could be a sign of a more serious underlying condition. Petechiae are small, red or purple dots that appear on the skin due to minor bleeding from broken capillaries. In the context of leukemia and thrombocytopenia (low platelet count), petechiae are common due to impaired clotting mechanisms.

Choice B rationale:

Bruising occurs due to damage to blood vessels underneath the skin, resulting in the leakage of blood into the surrounding tissues. Bruises are typically larger than petechiae and can occur with various conditions, including trauma. In this case, the small 1-mm red macules are more indicative of petechiae.

Choice D rationale:

Ecchymosis refers to a larger area of subcutaneous bleeding or bruising. It is larger than both petechiae and purpura and often results from more significant trauma or bleeding disorders. The description of multiple 1-mm red macules is characteristic of petechiae rather than ecchymosis.

Choice A rationale:

Serotonin is a neurotransmitter that plays a role in mood regulation, sleep, and other functions in the body. It is not a component that forms an adhesive bridge between platelets and vascular subendothelial structures in the clotting process.

Choice B rationale:

Platelet factor III is not a component that forms an adhesive bridge between platelets and vascular subendothelial structures in the clotting process. Platelet factor III is not widely recognized in the context of clotting; it is more commonly referred to as tissue factor and is involved in the extrinsic pathway of coagulation.

Choice C rationale:

Von Willebrand factor (VWF) is a protein that plays a crucial role in hemostasis. It forms an adhesive bridge between platelets and vascular subendothelial structures, particularly at sites of vascular injury. VWF helps platelets adhere to the injured vessel wall, leading to the formation of a stable blood clot. This process is essential for preventing excessive bleeding. A deficiency or dysfunction in VWF can lead to von Willebrand disease, a bleeding disorder characterized by prolonged bleeding times.

Choice D rationale:

Adenosine diphosphate (ADP) is a molecule released by platelets when they are activated. ADP helps in the aggregation of platelets, but it does not directly form an adhesive bridge between platelets and vascular subendothelial structures.