1. Chapter 14: The Cardiovascular System- Blood

2. Functions of the Blood 1)Transportation -Gases (O 2 and CO 2 ) -Nutrients -Heat and waste -Hormones 2)Regulation -pH -Temperature -Osmotic pressure of cells 3)Protection -Blood loss -Sickness/Disease

3. Components of Blood -A type of connective tissue -Two main components: 1)Blood Plasma (55%) -Water, Protein, Amino Acids 2)Formed Elements (45%) - RBCs, WBCs, Platelets -Hematocrit: % of total blood volume occupied by RBCs

4. Blood Plasma -91% Water -7% Proteins (plasma proteins) -Albumins: maintain osmotic pressure -Globulins: immune responses -Fibrinogen: forms blood clots -2% Other Solutes -Electrolytes, nutrients, enzymes, hormones, vitamins, etc

6. Formed Elements -Red Blood Cells, White Blood Cells, Platelets -Developed through hemopoiesis -Early Development: Occurs in embryonic yolk sac, liver, and lymphatic organs -Late Development/After Birth: red bone marrow -Pluripotent stem cells become specialized blood cells

7. Red Blood Cells-Erythrocytes -Transports oxygen and carbon dioxide -Contain hemoglobin -Oxygen carrying protein -Gives blood its red color -Bioconcave disc -No nucleus or organelles

8. RBC Life Cycle -Approximately 5 million RBC/µL blood -RBC Life span = 120 days -2 million new cells produced every second

9. + + Circulation for about 120 days Reused for protein synthesis Amino acids Red blood cell death and phagocytosis Macrophage in spleen, liver, or red bone marrow Urine Kidney Feces Bacteria Large intestine Small intestine Liver Erythropoiesis in red bone marrow Erythopoietin Vitamin B 12 Key: in blood in bile 1 2 2 3 4 5 6 10 7 Globin Transferrin Iron Heme Biliverdin Bilirubin Urobilinogen Stercobilin Globin + Urobilin RBC Life Cycle

10. RBC Production -Hemopoiesis: formation of blood cells -Erythropoiesis: formation of only RBCs -RBC precursor ejects nucleus -> bioconcave shape forms -Iron + Globlin + B 12 form hemoglobin -> Stimulated by Erythropoietin -RBCs become fully mature while in circulation -Hypoxia (oxygen deficiency) stimulates increased release of erythropoietin -Prolonged hypoxia, often caused by anemia, can lead to cyanosis Erythopoietin Vitamin B 12 Iron Globin

11. Some stimulus disrupts homeostasis by Oxygen delivery to kid- neys (and other tissues) Receptors Kidney cells detect low oxygen level Control center Stem cells in red bone marrow mature more quickly into RBC precursors Effectors Larger number of RBCs in circulation Increased oxygen delivery to tissues Return to homeostasis when oxygen delivery to kidneys increases to normal Increased erythropoietin secreted into blood Input More RBCs enter circulating blood Output Decreasing

12. Medical Tests Involving Blood -Reticulocyte (RBC precursor cells) count: rate of erythropoiesis -High reticulocyte count may indicate internal bleeding or iron deficiency -Low reticulocyte count + anemia may indicate malfunctioning red bone marrow -Hematocrit count: percent of RBCs -Used to diagnose anemia, polycythemia, and dehydration or over hydration -Athletes and people at high altitudes have higher-than avg hematocrit

13. EPO Doping