Human Anatomy: Blood and Heart PDF

6 Human Anatomy Chapter 6: Blood and Heart 1 Part I FUNCTIONS AND PROPERTIES OF BLOOD 2 Function of Blood 1. Transportation ◼ Gases, nutrients, hormones, waste products 2. Regulation ◼ pH, body temperature, osmotic pressure 3. Pro...

6 Human Anatomy Chapter 6: Blood and Heart 1 Part I FUNCTIONS AND PROPERTIES OF BLOOD 2 Function of Blood 1. Transportation ◼ Gases, nutrients, hormones, waste products 2. Regulation ◼ pH, body temperature, osmotic pressure 3. Protection ◼ Clotting, white blood cells, proteins Physical characteristics of blood ◼ Volume – 8% of body weight. 4~5 L in females; 5~6 L in males. ◼ pH – 7.35 to 7.45 ◼ Temperature – 38C 3 Components of Blood ◼ Blood plasma – water liquid extracellular matrix (55%) ◼ Formed elements – cells and cell fragments (45%) 4 5 1. Blood Plasma ◼ 91.5% water, 8.5% solutes and proteins ❑ Hepatocytes (liver cells) synthesize most plasma proteins ◼ Albumins, globulins (e.g. antibodies), fibrinogen ❑ Other solutes include electrolytes, nutrients, enzymes, hormones, gases and waste products Serum = plasma – the clotting proteins 6 2. Formed Elements ◼ Red blood cells (RBCs) or Erythrocytes ❑ Hematocrit: the percentage of total blood volume occupied by RBCs. Females:38-46%; males: 40-54% ◼ White blood cells (WBCs) or Leukocytes ❑ Granular leukocytes ◼ Neutrophils ◼ Eosinophils ◼ Basophils ❑ Agranular leukocytes ◼ T and B lymphocytes and natural killer (NK) cell ◼ Monocytes ◼ Platelets or Thrombocytes 7 Formed Elements of Blood 8 Formation of Blood Cells ◼ Hematopoiesis or hemopoiesis: Process of blood cell production ❑ Red bone marrow primary site ❑ Stem cells in red bone marrow ◼ Reproduce themselves ◼ Proliferate and differentiate ◼ All formed elements derived from single population differentiated from the stem cells ◼ Pluripotent stem cells to Myeloid stem cells and Lymphoid stem cells ❑ Formed elements do not divide once they leave red bone marrow ◼ Exception is lymphocytes ❑ Cells enter blood stream through sinusoids 19-9 10 Formation of Blood Cells ◼ Hemopoietic growth factors regulate differentiation and proliferation Stimulate the Production site production of Erythropoietin (EPO) RBCs kidney Thrombopoietin (TPO) platelets liver Colony-stimulating WBCs red bone marrow, factors (CSFs) and leukocytes, interleukins macrophages, fibroblasts, and endothelial cells… 11 Part II RED BLOOD CELLS/ ERYTHROCYTES 12 Overview of RBCs ◼ Structure ❑ Biconcave, anucleate ◼ Components ❑ Hemoglobin ❑ Lipids, ATP, carbonic anhydrase ◼ Function ❑ Transport oxygen from lungs to tissues and carbon dioxide from tissues to lungs ◼ 4.8 x 106/ μL (female); 5.4 x 106/ μL (male) ◼ Disorders of RBC: Anemia 13 Anatomy and Physiology of RBCs ◼ Biconcave disc – increases surface area ◼ Strong, flexible plasma membrane ❑ Glycolipids in plasma membrane responsible for ABO and Rh blood groups ◼ Lack nucleus and other organelles ❑ No mitochondria – doesn’t use oxygen 14 Hemoglobin Hemoglobin - 16g/100 ml in males; 14g/100 ml in females ◼ 4 globin molecules: Transport carbon dioxide (carbonic anhydrase involved), nitric oxide ◼ 4 heme molecules: Transport oxygen ❑ Iron is required for oxygen transport ❑ One Iron ion locate at the center of each heme ring, can combine reversibly with one oxygen molecule 15 Shapes of RBC and Hemoglobin 16 17 RBC Life Cycle ❑ Live only about 120 days ◼ Cannot synthesize new components – no nucleus ◼ Ruptured red blood cells removed from circulation and destroyed by fixed phagocytic macrophages in spleen and liver ◼ Production = destruction ❑ with at least 2 million new RBCs per second ❑ Breakdown products recycled ◼ Globin’s amino acids reused ◼ Iron reused ◼ Non-iron heme ends as yellow pigment urobilin in urine or brown pigment stercobilin in feces 20 Hemoglobin Breakdown 21 Erythropoiesis: Production of RBCs ◼ Starts in red bone marrow with proerythroblast ❑ Cell near the end of development ejects nucleus and becomes a reticulocyte ❑ Develop into mature RBC within 1-2 days ◼ Control: ❑ Negative feedback balances production with destruction ❑ Controlled condition is amount of oxygen delivery to tissues ◼ Reduced oxygen (Hypoxia) cause kidney to release EPO (erythropoietin) which goes to the red bone marrow to increase erythropoiesis 22 23 Part III WHITE BLOOD CELLS/ LEUKOCYTES 24 Types of White Blood Cells/ Leukocytes Granular or agranular based on staining highlighting large conspicuous granules ❑ Granular leukocytes ◼ Neutrophils, eosinophils, basophils ❑ Agranular leukocytes ◼ T and B lymphocytes, NK cells, Monocytes 25 Functions of WBCs ◼ Usually live a few days. Except for lymphocytes – live for months or years ◼ Far less numerous than RBCs. Normal: 5,000 – 10,000/μL ❑ Leukocytosis (>10,000/μL) is a normal protective response to invaders, vigorous exercise, anesthesia and surgery ❑ Leukopenia (