Ch. 18 Blood-- Study Guide

1. Ch. 18 Blood-- Study Guide Critically read pp. 683-704 before “Leukocyte life cycle” section Comprehend Terminology (the text in bold) Study-- Figure questions, Think About It questions, and Before You Go On (section-ending) questions Do end-of-chapter questions: Testing Your Recall— 1, 3-6, 8, 9, 11, 12, 17-20 True or False– 1, 2, 3, 5, 8, 9 Testing Your Comprehension--1, 2, 3

2. Chapter 18– Blood The study of blood is called ___________ A-- Herpetology B-- Hematology C-- Homeostasis D-- Hercules

3. § 18.1--Introduction • Blood is a unique tissue; why? • What kind of tissue? Fig. 18.0

4. CO 18 An RBC, WBCs, and four platelets (SEM)

5. § Functions of Circulatory System • Transport • O2, CO2, nutrients, wastes, hormones, and heat • Protection • WBCs, antibodies, and platelets • Regulation • fluid regulation, buffering, body temp.

6. § Two Components of Blood Adults have 4-6 L of blood • Plasma– 55% of total volume Including— • Cellular (formed) elements— 45% Including— How to separate these two components? (see next slide Fig. 18.2)

7. Figure 18.2 Hematocrit-- The percentage of the total blood volume that is occupied by __________ (see next slide)

8. Assuming this tube contains a patient’s blood after centrifugation, what’s his/her blood hematocrit? Plasma = 55% of whole blood A. Platelets “Buffy coat” <1% B. WBCs Cellular elements (= @ 46%) C.Red blood cells = @45% of whole blood

9. § Seven Kinds of Formed Elements in Blood— 2 4 1 7 6 3 5

10. Formed Elements of Blood • Erythrocytes (RBCs) • Platelets • Leukocytes (WBCs) • A. Granulocytes— • Neutrophils (no. 3) • Eosinophils (no. 4) • Basophils (no. 5) • B. Agranulocytes— • Lymphocytes (no. 6) • Monocytes (no. 7)

11. § Blood Plasma (top layer) Including– Table 18.2 (page 687) • Water (90% by weight)-- • Most abundant molecule in the plasma • Function: • Electrolytes (Ions)– • What: sodium ions, … • Function: • Plasma proteins (8%)– (details next slide) • Others (2%)– Nutrients, . . .

12. § Plasma proteins (top layer) • Albumins (60% of plasma proteins)– Functions— transport molecules, the major contributor of osmotic pressure and blood viscosity etc. • Globulins (36%)– (alpha, beta and gamma) Functions– transport molecules, blood clotting factors, gamma-- antibodies • Fibrinogen (4%)– becomes fibrin, the major blood-clotting factor • Where are plasma proteins formed?

13. § Blood Viscosity and Osmolarity • Blood Viscosity - resistance to flow • Causes: Blood is thicker than water; Why? • Too much vs. too little • Blood Osmolarity • Def. total molarity (concentration) of dissolved particles in 1L of solution. . . • high osmolarity (compared with __________) • causes fluid absorption into blood, raises BP • low osmolarity • causes fluid to remain in tissues, may result in edema (Example– see Fig. 18.3)

14. Fig. 18.3--Starvation and Plasma Protein Deficiency—Ascites and Kwashiorkor

15. § 18.2--Red Blood Cells (RBCs) or Erythrocytes • Disc-shaped cell with thick rim • 7.5 M diameter and 2.0 m thick at rim • Blood typesdetermined by surface glycoprotein and glycolipids • cytoskeletal proteins (spectrin and actin) give membrane durability; importance: • Fig. 18.4 a and c

16. Figure 18.4a Fig. 18.4a

17. Figure 18.4c A Transmission Electron Microscope picture.

18. § Erythrocytes (RBCs) Function • Gas transport - major function • increased surface area/volume ratio due to ________ shape • 98% of cytoplasm is hemoglobin (Hb) • O2 delivery to tissue and CO2 transport to lungs • Carbonic anhydrase (CAH) in RBC • produces carbonic acid from CO2 and water • important role in gas transport and pH balance

19. § Hemoglobin (Hb) Structure • Globins - 4 protein chains • 2 alpha and 2 beta chains (HbA) • HbA vs. HbF-- • Heme groups • Conjugate with each protein chain • Bind O2; where? • How many in 1 Hb?

20. § Erythrocytes and Hemoglobin • RBC count and hemoglobin concentration indicate amount of ______ blood can carry: • hematocrit (packed cell volume) - % of whole blood composed of RBCs; 45% vs. 40% (M vs. F) • hemoglobin concentration of whole blood (g/dL); 16 vs. 14 (M vs. F) • RBC count; (millions RBCs/microliter ); 5.4 vs. 4.8 • Values are lower in women; Why? • Hormone (Testosterone) • Others

21. § Hemopoiesis • Adult produces 400 billion platelets, 200 billion RBCs and 10 billion WBCs every day • Hemopoietic tissues produce blood cells: • Fetal life-- yolk sac produces stem cells, migrating to Bone marrow, liver, spleen, thymus • (at birth) liver stops producing blood cells at birth • spleen remains involved with Lymphocytes production; Lymphoid hemopoiesis– where? Thymus etc. • red bone marrow • pluripotent stem cells, why? • myeloid hemopoiesis produces RBCs, WBCs and platelets

22. Our focus

23. § Erythrocyte Production (1) • 2.5 million RBCs/sec, called Erythropoiesis • How long does the process take? • 4 major developments– in Cell size, Cell no., Hb, Cellular organelles A. Pluripotent stem cells become committed cells – B. erythrocyte colony forming unit (ECFU)

24. § Erythrocyte Production (2) C. Erythroblasts-- multiply and synthesize hemoglobin • Discard nucleus to form a reticulocyte D. Reticulocytes— Name? • Characteristics: E. Mature RBCs--

25. § Erythrocyte Production (3) Intracellular features of RBCs— • A. No nucleus & organelles (ribosome etc) Why? • B. RBCs are plasma mem. sacs full of Hb • C. Where is ATP produced in RBCs? By what key biochemical processes? • D. When are key enzymes being produced?

26. § Iron and Erythropoiesis (Fig. 18.7) • Iron - key nutritional requirement, why? • Lost through urine, feces, and bleeding • requires dietary consumption of iron, ferric (Fe3+) and ferrous (Fe2+) ions; Steps: • converts Fe3+ to absorbable Fe2+,where? • G-I tract— Gastroferritin binds Fe2+ • In blood-- absorbed into blood and binds to Transferrin for transport • Liver-- Apoferritin binds Fe2+to create ferritin for storage Fig. 18.7 (iron metabolism)

27. Good/excellent sources of iron: ?

28. In-class activity • Give one disease related to low plasma proteins. Explain your answer.

29. Other Needs for Erythropoiesis • Vitamin B12 and folic acid: • rapid cell division etc. (in the red bone marrow) • Where can red marrow be found in adults? • In axial skeleton: girdles . . . • Vitamin C and copper: • cofactors for enzymes synthesizing Hb

30. § Erythrocyte Homeostasis (1) • Negative feedback control • What is the controlled variable? • Hypoxemia-- causes • 1. Drop in RBC count -- 2. Others (next slide) Results: • EPO production stimulates bone marrow • RBC count  in 3 - 4 days 18-30

31. § Erythrocyte Homeostasis (2) • Stimuli for erythropoiesis • low levels O2; in Tibet, Himalaya • increase in oxygen consumption • less lung tissue available (emphysema) • All these factors contribute to secondary polycythemia (details later)

32. § Erythrocytes Recycle/Disposal Macrophages in spleen, liver, & red bone marrow • Digest mem. fragment & separate heme from globin; Globins into free _______ (into blood) • Dispose/reuse the heme: • Iron (into blood); Heme converted to biliverdin (green) and then bilirubin (yellow, into blood) • liver pick up & secretes bilirubin (into bile; small intestine); bacteria create urobilinogen (brown feces) • Some bilirubin becomes urochrome (into yellow urine) Fig. 18.9 and x

33. Fig. 18.9 Life & Death of RBCs • Fate of RBC— • Life span– • Where are RBCs’ final demise?

34. Summary of RBC Life Cycle

35. § Erythrocyte Disorders • 1. Polycythemia - an excess of RBCs • primary polycythemia • cancer of erythropoietic cell line in red bone marrow • RBC count as high as 11 million/L; hematocrit 80% • secondary polycythemia -- • from dehydration, emphysema, high altitude, or physical conditioning (all due to hypoxemia . . .) • RBC count up to 8 million/L • Dangers of polycythemia • increased blood volume, pressure, viscosity lead to embolism (obstruction of the blood vessels) . . .

36. § 2. Anemia – Causes/Categories • A. Inadequate erythropoiesis or hemoglobin synthesis-- • kidney failure and insufficient erythropoietin • inadequate vitamin B12 from poor nutrition or lack of intrinsic factor (pernicious anemia) • iron-deficiency anemia • Hypoplastic and aplastic anemia – decline or complete cessation of erythropoiesis • B. Hemorrhagic anemia-- • C. Hemolytic anemia– RBC destruction TABLE 18.4 is an excellent table for review

37. Anemia - Effects • Tissue hypoxia and necrosis (the individual is short of breath and lethargic)– esp. Brain, heart, and kidney tissue • Low blood osmolarity (→ tissue edema) • Low blood viscosity (→ heart races and bloodpressure drops)– heart failure

38. § 3. Sickle-Cell Disease • Hereditary Hb ‘defect’; caused by recessive allele modifies hemoglobin structure (HbS) • sickle-cell trait - heterozygous for HbS; (HbA/HbS) • sickle-cell disease - ______________ for HbS • Details Fig. 18.10 • HbS polymerize and become sickle shape; cell stickiness causes agglutination and blocked vessels • intense pain in oxygen-starved tissues; kidney and heart failure, stroke, paralysis; hemolysis of the fragile RBCs: anemia and hypoxemia • chronic hypoxemia stimulates hemopoietic tissue (enlarged spleen, misshapen bones such as cranium)

39. Sickle-Cell Diseased Erythrocyte Fig. 18.10

40. Muddiest points of this chapter?