Blood Topics Functions and Properties of Blood Components of Blood Blood Cell Formation Red Blood Cells White Blood Cells Platelets Hemostasis Blood Groups and Blood Transfusion

White Blood Cells White blood cells contribute to the body’s defense against pathogens.

White Blood Cells Nucleated Combat inflammation and infection Granular or agranular

White Blood Cells Neutrophils Lymphocytes Monocytes Eosinophils Basophils

Never Let Monkeys Eat Bananas White Blood Cells Never Let Monkeys Eat Bananas

Granular Leukocytes Neutrophils Prevalence 60-70% Structure Multilobed nucleus Fine pale lilac granules Function Phagocytosis Bacterial destruction

Granular Leukocytes Eosinophils Prevalence 2-4% Structure Bilobed nucleus Large red-orange granules Function Diminish inflammation Phagocytosis

Granular Leukocytes Basophils Prevalence 0.5-1% Structure Bilobed nucleus Large deep-blue granules Function Intensify inflammation

Agranular Leukocytes Lymphocytes Prevalence 20-25% Structure Large dark-staining nucleus No granules Function Mediate immune response “Soldiers”

Agranular Leukocytes Monocytes Prevalence 3-8% Structure Large kidney-shaped nucleus No granules Function Phagocytosis

WBC Identification

WBC Identification

WBC Life Cycle RBM  lymphatic tissues Most WBCs are short-lived 5,000-10,000 WBCs per μL Leukocytosis Leukopenia WBCs emigrate from vessels

WBC Life Cycle Leukocytes + monocytes  never re-enter circulation Lymphocytes  continually recirculate ~2% in blood

Blood Topics Functions and Properties of Blood Components of Blood Blood Cell Formation Red Blood Cells White Blood Cells Platelets Hemostasis Blood Groups and Blood Transfusion

Platelets Platelets are disc-shaped fragments of megakaryocytes that function in the clotting process.

Platelets Irregularly shaped cell fragments Vesicles but no organelles 150,000 – 400,000 per uL 1/3 stored in spleen Promote hemostasis Live about 10 days Macrophages in spleen and liver

Platelet Formation Formed from megakaryoctyes in red bone marrow

Blood Topics Functions and Properties of Blood Components of Blood Blood Cell Formation Red Blood Cells White Blood Cells Platelets Hemostasis Blood Groups and Blood Transfusion

Hemostasis Hemostasis is a series of carefully controlled responses that stop bleeding

Hemostasis Series of carefully controlled responses. Three mechanisms contribute to hemostasis: Vascular spasm Platelet plug formation Blood clotting

Vascular Spasm Vessel reflexively vasoconstricts when damaged Slows blood loss Immediate, but not long lasting

Platelet Contents Clotting factors ADP, ATP Ca2+ and serotonin Enzymes  thromboxane A2 Fibrin-stabilizing factor Platelet-derived growth factor (PDGF)

Platelet Plug Formation Three steps: Platelet adhesion Platelet release reaction Platelet aggregation Plug formation allows time for clotting and healing

Platelet Plug Formation

Platelet Plug Formation

Platelet Plug Formation

Platelet Plug Formation https://youtu.be/R8JMfbYW2p4