BIOS 255 A&P III Final Exam Study Guide
Chapter 19
Blood
• Formed Elements
o RBCs
o WBCs
o Platelets
• Hemoglobin –
o Protein, which is used to carry O2 to tissue and approximately 20% of
CO2 back to the lungs.
o Each Hemoglobin molecule can contain 4 “Heme” (iron) Ions which
allow each hemoglobin molecule to bind with up to 4 O2 molecules.
o Nitric Acid (NO) can bind to Hemoglobin, when released triggers
Vasodilation. Increases Blood flow.
• Centrifuge of Blood
o Top – Plasma – 55%
o Middle (BUFFY COAT) – Platelets & WBC
o Bottom – RBC – 45%
• Functions of Blood
o Transportation
▪ O2
▪ CO2
▪ Hormones (from Endocrine Glands)
▪ Heat
▪ Waste (for Elimination)
▪ Nutrients (from GI Tract)
o Protection
▪ Immune Response (WBC)
• Macrophages (Phagocytosis)
• Globulin
▪ Blood Clotting – Fibrinogen - Hemostasis
▪ Against Disease
• Antibodies
• Interferons
• Complement System
o Regulation
▪ PH (Buffers)
• HCO3 –Bicarb Buffer
• H+ - - Hydrogen
▪ Body Temp
▪ Osmotic Pressure
▪ H2O content of cells.
• Hemopoiesis – Production of ALL blood cells.
Erythrocytes – RBCs
▪ Transport of O2 & CO2
, 2
▪ No Nucleus
▪ No Organelles (Once mature)
▪ Biconcave Disk
▪ Live for Days/weeks
• Dead RBC go to the Liver/Spleen ->Macrophages break
down (recycle)-> Heme & Globulin -> Iron (from
Heme) & Amino Acids (from Globulin)
o Erythropoiesis – Production of RBC
▪ Occurs in Red Bone Marrow
• Produces Reticulocytes (immature RBC) which
circulate in blood for 1-2 days before maturing into
RBC
o Erythropoietin – A hormone releases by the Kidneys in response to
Hypoxia (low O2 levels) to stimulate Erythropoiesis.
o Hematocrit - % of total blood occupied by RBC.
▪ 42% in Women
▪ 47% in Men
• Anemia – Low RBC count
• Polycythemia – High RBC count
o Increased Viscosity
o Increased Resistance
o Decreased Flow
Carbonic Anhydrase (CA)
o Enzyme that catalyzes the conversion of CO2 and H2O to Carbonic
Acid
o Carbonic Acid then dissociates into H+ and HCO3 (reversible reaction)
o Reaction allows up to 80% of CO2 to be transported in blood plasma to
the lungs as HCO3-
o Reaction also serves as a buffer in extracellular fluid
CO2+H2O→H2CO3 (Carbonic Acid)→ H+ + HCO3- (Bicarbonate Ions)
Leukocytes – WBC
o Has a Nucleus
o Has Organelles
o No Hemoglobin
o Can live for years
WBC Function
Granular Neutrophil Phagocytosis
, 3
Eosinophil Combats Histamine,
Phagocytize antigen-antibody
complexes, Destroys certain
parasitic worms.
Basophil Liberates Heparin, and Serotonin
in allergic reactions that intensify
inflammatory response.
Agranular Lymphocytes B-Cells Develop into plasma cells which
secrete antibodies.
T-Cells Attack invading viruses, cancer
cells and transplant tissue.
Natural Killer (NK) Cells Attack a wide variety of
infectious microbes & certain
spontaneously arising tumors.
Agranular Monocytes Phagocytosis
• Emigration / Diapedesis
o Leukocytes leaving the blood to accumulate at the site of invasion
• Leukocytosis
o Normal response to stress which causes an increase in WBC
• Leukopenia
o Abnormally low levels of WBC caused by radiation, shock or
chemotherapy
Thrombocytes – Platelets
• Live for 5-9 Days
• Used for blood clotting
• Mature from Megakaryocytes in red bone marrow
• Thrombopoiesis – Platelet production
• Hemostasis – Prevent blood loss
o Vascular Spasm
▪ Contraction of smooth muscle in blood vessels to
close wound and prevent wound
• Lasts seconds to hours
o Platelet plug formation
o Blood clotting (Coagulation)
▪ Extrinsic Pathways
▪ Intrinsic Pathways
▪ Common Pathways
• Vitamin K – Required for synthesis of 4 different clotting factors
o Is fat soluble
• Clotting factors
, 4
o Calcium (Ca2) ions activate enzymes that are synthesized by
hepatocytes and released into the bloodstream.
o Molecules associated with platelets or released by damaged tissue
o Roman numerals from I-VIII (1-13)
• Plasmin (Fibrinolysin)
o Fibrinolysis is the process where small clots are dissolved
into the blood.
o Plasmin activates the inactive plasma enzyme, Plasminogen
which is incorporated into the clot when the clot is formed.
Plasma
o 90% water
o Proteins – made by Hepatocytes (Liver Cells)
o Albumin
▪ 54%
▪ Maintaining Osmotic Pressure
o Globulin
▪ 38%
▪ Pressure Immune response
o Fibrinogen
▪ 7%
▪ Clotting
o Solutes
o Electrolytes
o Nutrients
o Waste Products
o Gasses
o Regulatory Substances
o Antibodies
Blood Osmotic Pressure
o Influences the water content of cells, through interactions of dissolved
ions and proteins
Hormonal Regulation