ANP 1105 Chapter 17: Blood Clotting (Platelets) and Blood Types

• School: University of Ottawa
• Department: Anatomy and Physiology
• Course: ANP 1105
• Professor: Joanne Savory

Document Summary

Anp1105 a dr. joanne savory and dr. m zeroual. Blood pt 2 platelets and blood clotting (ch 17) Technically not a cell, they are cytoplasmic fragments of megakaryocytes (large cell); irreversible, must become platelet: anucleate so they age quickly and degenerate in 10 days if not involved in clotting. Blue-staining outer region; purple granules containing serotonin, ca2+, enzymes, adp, and platelet-derived growth factor (pdgf) these elements act in clotting process. Megakaryoblast (stage i) goes through repeated mitoses but not cytokinesis; makes. Megakayrocyte (stage ii/iii); mature megakaryocyte (stage iv), with multilobed nucleus and large cytoplasmic mass, break off into tiny pieces to make platelets (fragments of hemoglobin) Normal person has 150 000 400 000 platelets/microliter of blood. Hemostasis: process the body goes through to stop bleeding and maintain blood volume requires clotting factors and substances released by granules from platelets and injured tissues.