Blood Biology 2122 Chapter 17

Characteristics/Functions 1.Connective Tissue (Formed Elements) 2.pH: Males: 5-6 L; Females: 4-5 L 4.O 2 and CO 2 ; Hormone Transport 5.Regulatory (Body Temperature; pH; Fluids) 6.Protection: Antibodies-Immune System

Blood Composition 1.Plasma (55%) – Dissolved solutes; Water 2.Formed Elements – Erythrocytes; Leukocytes; Platelets 3.Buffy Coat 4.Proteins – Albumin

Erythrocytes 1.Function/Structure – Biconcave discs – No mitochondria – Functions Gas Transport; Hb and oxygen gas affinity Delivers oxygen gas to cells; carbon dioxide as waste 2. Concentration – Hematocrit – Females vs. Males

Production Hematopoiesis-Erythropoiesis Life Span: 120 days Stem Cell: Hemocytoblast

Regulation, Destruction and Disorders

Leukocyte Classification 1.Granulocytes – Neutrophils; Eosinophils; Basophils – Larger; short-lived compared to RBC 2.Agranulocytes – Lymphocytes; Monocytes – No cytoplasmic granules – Specific immune response

Characteristics of Granulocytes 1.Neutrophils – Polymorphonuclear Leukocytes (PMNs) – Lilac stain 2.Eosinophils – Pink Granules (acid stain); large – Parasitic Worms 3.Basophils – Lg. granules (blue-basic); Histamine; U or S-shaped nuclei

Characteristics of Agranulocytes 1.Lymphocytes – Dk. Purple Spherical nuclei – T and B-Cells (Specific Immunity) 2.Monocytes – U-Shaped nuclei – Macrophages

Leukocyte Production 1.Leukopoiesis 2.Stem Cell 3.Stimulated by Chemical Messengers – Glycoproteins (Interleukins and Colony-Stimulating Factors 4. Pathways – Lymphoid vs. Myeloid Stem Cells

Blood Groups and Blood Types 1.ABO Groups – Based on presence or absence of surface antigens (agglutinogens) – A or B – Plasma: antibodies (agglutinins) – Type O (universal donor); Type AB (universal receiver) 2. Rh antigens (Factors) – 85% are positive 3. Frequency – O>A>B>AB

Hemostasis – How Blood Vessels Repair Themselves 1.Blood vessels undergo damage – unseen 2.Hemostasis - response to this damage 3.“Plugging the Hole” – Clot Formation 4.Stages – Vascular Spasm – Platelet Plug – Coagulation

Spasms and Plugs 1.Vascular Spasm – Damaged blood vessels (vascular smooth muscle)  Chemicals  constriction (spasm) – “Vasoconstriction” – Most Effective – small blood vessels 2.Platelet Plug Formation – Platelets “aggregate”  Plug (temporary) – Adhere to exposed collagen fibers – Von Willebrand factor; ADP; Serotonin; Thromboxane

Coagulation – ‘blood clotting’ 1.Multi-step pathway (mediated by clotting proteins) 2.Platelets – reinforced by fibrin (fibrin mesh) 3.Clotting Factors (plasma proteins) – Factors activated (enzyme) – Cause a ‘cascade effect’ – I – XIII

Pathways

Pathways - Prothrombin Activator 1.Both factors cascade – common factor X – Prothrombin activator 2.Prothrombin activator catalyzes transformation of prothrombin to thrombin. 3.Thrombin – Fibrinogen Fibrin – Insoluble strands glue platelets – clot – Factor XIII activated (binds fibrin strands)

Hemostasis 4. Clot Retraction – stabilizes the clot 5. PDGF – promotes smooth muscle cells and fibroblast to repair wall. 6. Fibrinolysis – removes unnecessary clots – Plasmin (clot buster) – Heparin; Antithrombin III (anticoagulants) – Hemostasis Animation Hemostasis Animation

Disorders 1.Thromboembolic Disorders – Thrombus – Embolus – Embolism – DVT Animation DVT Animation 2. Bleeding Disorders – Hemophilia