What is the main function of platelets in the blood?
A. Oxygen transport
B. Infection control
C. Blood clotting
D. Nutrient delivery
Answer (1)
The answer is C. Blood clotting Platelets, also called thrombocytes, are small, disk-shaped cell fragments in the blood whose main job is to initiate clotting when a blood vessel is injured. They are produced in the bone marrow and circulate in the bloodstream, ready to respond when bleeding occurs.When a vessel is damaged:Platelets are attracted to the injury site.They stick together and to the vessel wall, forming a temporary plug.They release chemical signals that activate other clotting factors, forming a fibrin mesh that stabilizes the clot and seals the wound.This process, called hemostasis, prevents excessive blood loss and is vital for survival. Without platelets, even minor injuries could result in life-threatening bleeding.Normal platelet counts range from 150,000 to 450,000 per microliter of blood. Too few platelets (thrombocytopenia) increases bleeding risk. Too many platelets can cause abnormal clotting, leading to strokes or heart attacks.Platelets differ from:Red blood cells, which carry oxygen.White blood cells, which fight infection.Plasma, which transports nutrients and hormones.Conditions affecting platelets include:Hemophilia – a clotting disorder where platelets don’t function properly.Dengue fever – often causes dangerously low platelet counts.Leukemia – may reduce platelet production in bone marrow.Understanding platelets teaches students the importance of clotting, the danger of bleeding disorders, and why cuts eventually stop bleeding. It’s also a foundation for first aid, emergency care, and blood donation awareness.
