Serotonin is sexreted by: (A) Leukocytes, (B) RBCs, (C) Platelets, (D) Vessel wall
Answer is C. platet seretonin normally the seratonin secreted from the enterochromaffin cells enters the blood stream . the platelets when bind to the clot release seratonin where it xan help in vaso constriction or dilation and hels in hemostasis Ref: Katzung 12 th ed.