NURS 611 Exam 3 Study Guide (Week 8 The Hematologic System: Chapters 28, 29 & 30)

NURS 611 Advanced Pathophysiology Exam #3 Study Guide Week 8 The Hematologic System: Chapters 28, 29 & 30 Chief Functions I. Delivery of substances needed for cellular metabolism in the tissues (Transports hormone ...

NURS 611 Advanced Pathophysiology Exam #3 Study Guide Week 8 The Hematologic System: Chapters 28, 29 & 30 Chief Functions I. Delivery of substances needed for cellular metabolism in the tissues (Transports hormones; conveys WBCs, platelets, and other ingredients needed for protection from injury & infection & initiating the healing process) II. Removal of the wastes of cellular metabolism III. Defense against microbes & injury IV. Maintenance of acid-base balance (fluid portion carries nutrients & ions) Extra functions: RBCS provide O2 and remove CO2, Provides thermal regulation to maintain organs & tissues Blood Composition: various cells that circulate in the CV system suspended in a solution of protein & inorganic materials (plasma), which is 92% H2O and 8% solutes * Total of 6 quarts (5.5L) Plasma & Plasma Proteins- 50-55% blood volume, complex aqueous liquid containing organic & inorganic elements * Serum refers to plasma that has been allowed to clot in a lab in order to remove fibrinogen and other clotting factors * Proteins make up 7% of total plasma weight, majority made by the liver with the exception of antibodies (made by plasma cells in the lymph nodes & other lymphoid tissues), classified into two major groups: albumin & globulins Albumin: most essential role is regulation of the passage of H2O and solutes through the capillaries, maintain the colloidal osmotic pressure Globulins: classified by their movement relative to albumin: alpha (ones that move most like albumin), beta, and gamma (least movement) * Fibrinogen, the most plentiful of the clotting factors & is the precursor of the fibrin clot * Can also be classified into groups by function: clotting, defense, transport or regulation Cellular Components of Blood: RBCs (erythrocytes), WBCs (leukocytes), and platelets (thrombocytes) A. Erythrocytes * Most abundant cells (42-48% of blood) * Contains hemoglobin (carries gases and electrolytes) * Small disk with 2 unique properties: Biconcave shape and capacity to be reversibly deformed B. Leukocytes * Defend against microbes and remove debris * Act primarily in the tissues but transported via circulation * Classified according to structure as either granulocytes (neutrophils, basophils, eosinophils & mast cells) or agranulocytes (monocytes, macrophages, lymphocytes) & according to function as either phagocytes (monocytes & macrophages) or immunocytes (lymphocytes) C. Platelets (not true cells but irregularly shaped cytoplasmic fragments needed for blood coagulation) Lymphoid Organs: classified as either primary or secondary  Primary consist of thymus & bone marrow  Secondary consist of the spleen, lymph nodes, tonsils and Peyer patches in the ileum of the small intestine The Spleen: Largest of the secondary lymphoid organs * Site of fetal hematopoiesis, filters blood-borne antigens & cleanses the blood through the action of mononuclear phagocytes, initiates immune responses to blood-borne microbes, destroys aged erythrocytes and serves as a reservoir for blood Iron Cycle- approx. 67% of total body iron is bound to heme in erythrocytes (hgb) and muscle cells (myoglobin), approx. 30% is stored in mononuclear phagocytes (macrophages) and hepatic parenchymal cells as either ferritin or hemosiderin * Recycled made possible by the plasma carrier, transferrin * Tissue macrophage (primarily in the spleen) break down ingested erythrocytes and return iron to the bloodstream directly or after storing it Hemoglobin Synthesis- oxygen carrying protein of the erythrocyte, constitutes approx. 90% of the cell’s dry weight * Hgb packed RBCs take up O2 to the lungs and exchange it for CO2 in the tissues * Single erythrocyte can contain as many as 300 hgb molecules * Each hgb molecule is composed of 2 pairs of polypeptide chains (the globins) and 4 colorful complexes of iron plus protoporphyrin (the hemes), responsible for blood’s ruby-red color and O2 carrying capacity * Very dependent on nutritional intake. Two of the most important nutrients are Vitamin B6 (pyridoxine) & Iron * Male 16g/dL * Female 14g/dL Neurophilia- another term for granulocytosis, due to neutrophils being the most numerous of the granulocytes * Increase in the # of granulocytes (neutrophils, eosinophils, basophils) * Begins with the release of stored leukocytes from the venous sinuses of the marrow * Demand mature neutrophils exceeds the supply, marrow begins to release immature neutrophils * Premature release of the immature WBCs is responsible for the phenomenon known as Shift-to-the-left (Immaturity side). May see other systemic signs of infection such as fever Anemia * Reduction in the total circulating red cell mass or a decrease in the quality or quantity of hgb * Result from blood loss, impaired erythrocyte production, increased erythrocyte destruction or a combination of these factors * “-cytic” refers to cell size * “-chromic” refers to hgb content Type Description Aplastic Anemia Critical condition, caused by an autoimmune disease against hematopoiesis by activated cytotoxic T-cells -Characterized by pancytopenia, a reduction or absence of all 3 blood cell types -Resulting from failure or suppression of bone marrow to produce adequate amounts of erythrocytes, leukocytes, and thrombocytes Iron Deficiency Can arise with inadequate dietary intake or excessive blood loss - Most common cause of IDA in developed countries is pregnancy and chronic blood loss - Early symptoms are nonspecific & include fatigue, weakness, SOB, and pale earlobes, palms, & conjunctivae