Question

a) Describe the main differences between platelets and other mammalian cells.

b) What changes occur within a platelet when it is activated? Describe a micrograph that shows activated platelets?

Answer 1

a) Differences between platelets and other mammalian cells such as red blood cells.

Red blood cells contain hemoglobin while platelets lack hemoglobin.

Red blood cells are larger than platelets .

Mammalian red blood cells are circular and biconcave while platelets are spindle shaped.

Human red blood cells survive for 120 days while platelets survive for 3 to 7 days.

b) When platelet is activated, the fibrinogen joins two platelets with these receptors. Platelet activation occurs after attachment and adhesion events and activates the mechanisms like as thromboxane A2, ADP, thrombin, platelet activating factor and released from endothelial cells. Platelets undergo shape change, cytoskeleton rearrangement and organelle centralization.