1. Ch 11 Blood

2. Functions of Blood Deliver O2 Remove metabolic wastes
Maintain temperature, pH, and fluid volume
Protection from blood loss- platelets
Prevent infection- antibodies and WBC
Transport hormones

3. Plasma-55%
Buffy coat-<1%
Red Blood Cells -45%
Composition of Blood

4. Figure 11.1 on page 305 in our book

5. Formed Elements of the Blood
Erythrocytes (red blood cells)
Leukocytes (white blood cells)
Platelets (thrombocytes)
Formed elements: cells and

6. Blood Plasma Components-55%
90% Water
8% Solutes:
Proteins
Albumin (60 %)
Globulins (38%)
Fibrinogens (4%)
Gas
Electrolytes
Albumin: Osmotic pressure, transport molecules
Globulins: immune system, transport molecules
Fibrinogens: blood clots

7. Blood Plasma Components
Organic Nutrients
Carbohydrates
Amino Acids
Lipids
Vitamins
Hormones
Metabolic waste
CO2
Urea

8. Buffy Coat- <1%
Platelets
Leukocytes (WBC)

9. Platelets Small fragments of megakaryocytes
Formation is regulated by thrombopoietin
Blue-staining outer region, purple granules
Granules contain serotonin, Ca2+, enzymes, ADP, and platelet-derived growth factor (PDGF)
Platelets

10. Developmental pathway
Stem cell
Developmental pathway
Hemocyto-
blast
Promegakaryocyte
Megakaryoblast
Megakaryocyte
Platelets
Figure 17.12

11. Red Blood Cells -45%
Erythrocytes (red blood cells)

12. Erythrocytes

13. Erythrocyte7.5m in dia
·   Anucleate
·   Function- transport respiratory gases
·  Life span days and then destroyed in spleen (RBC recycling center)

14. Hemoglobin Four globin protein chains
Four heme molecules with an Iron atom: Iron attracted to oxygen

15. Hematopoiesis Erythropoiesis
The process of blood cell formation
Location: red bone marrow of axial skeleton
Erythropoiesis
Process of red blood cell formation

16. Hematopoiesis: Blood Cell Production
Hormones and growth factors push the cell toward a specific pathway of blood cell development
Hemocytoblasts

17. Erythropoiesis Phases in development Ribosome synthesis
Hemoglobin accumulation
Ejection of the nucleus and formation of reticulocytes
Reticulocytes then become mature erythrocytes
Committed
cell
Developmental pathway
Stem cell
Phase 1
Ribosome
synthesis
Phase 2
Hemoglobin
accumulation
Phase 3
Ejection of
nucleus
Proerythro-
blast
Early
erythroblast
Late
erythroblast
Reticulo-
cyte
Erythro-
cyte
Hemocytoblast
Normoblast

18. Regulation of Erythropoiesis
Too few RBCs leads to tissue hypoxia
Hypoxia: low oxygen levels
Too many RBCs increases blood viscosity
Viscosity: Thick, Sticky, semifluid
Balance between RBC production & destruction depends on:
Hormonal controls
Adequate supplies of iron, amino acids, and B vitamins

19. Regulation of Erythropoiesis
Causes of tissue hypoxia:
Hemorrhage or increased RBC destruction
Insufficient hemoglobin (e.g., iron deficiency)
Reduced availability of O2 (e.g., high altitudes)
Hypoxia: low oxygen levels

20. Hormonal Control of Erythropoiesis
Erythropoietin (EPO)
Stimulates erythropoiesis
Released by kidneys in response to hypoxia

21. Hormonal Control of Erythropoiesis
Effects of EPO
More rapid maturation of committed bone marrow cells
Increased circulating reticulocyte count in 1–2 days
Testosterone also enhances EPO production, resulting in higher RBC counts in males

22. Formation & Destruction of RBCs

23. Leukocytes

24. Types of Leukocytes
4,000-11,000 cells/mm 3
Never let monkeys eat bananas
Granulocytes: granules in cytoplasm Neutrophils % Eosinophils- 1-4% Basophils- <1% Agranulocytes: no granules in cytoplasm Monocytes- 4-8% Lymphocytes %

25. Neutrophil
Eosinophil
Basophil
Lymphocyte
Monocyte