Chapter 19: Blood Flashcards
Blood: Plasma and Formed Elements
erythrocytes (red blood cells) carry oxygen
thrombocytes (platelets) for hemostasis
leukocytes (white blood cells) for defense/immunity
Abnormal Numbers of WBCs
Leukopenia: decreased # of WBCs in blood
Leukocytosis: elevated # of WBCs in blood
Hemostasis
a sequence of responses that stops bleeding
Coagulation factors: Clotting
Clotting is initiated by tissue or vessel damage, leading to production of thrombin. Thrombin (an enzyme) catalyzes the conversion of soluble fibrinogen to insoluble fibrin threads, forming a network to trap blood cells.
Blood Groups: Isoantigens
genetically determined blood group antigens on RBCs
ABO group: A and B isoantigens
Type A = only A antigens present on RBCs
Type B = only B antigens present
Type AB = both A and B antigens present
Type O = neither A nor B present
Universal recipients and donors
People who are AB+ are universal recipients, meaning they can safely receive a blood transfusion of any other blood type. 1 O- individuals are universal donors
Hemopoiesis: Formation of Blood Cells
stem cells in red bone marrow produce: Lymphoid stem cells (give rise to T and B lymphocytes)
Myeloid stem cells (give rise to all other blood cells and platelets)
Erythropoietin (from kidneys stimulates…
RBC formation
Thrombopoietin (from liver) stimulates…
platelet production
Cytokines (hormones from WBCs) stimulate…
WBC Production
