Ch. 18 Blood-- Study Guide 1.Critically read pp before “Leukocyte life cycle” section 2.Comprehend Terminology (the text in bold) 3.Study-- Figure questions, Think About It questions, and Before You Go On (section- ending) questions 4.Do end-of-chapter questions: –Testing Your Recall— 1, 3-6, 8, 9, 11, 12, –True or False– 1, 2, 3, 5, 8, 9 –Testing Your Comprehension--1, 2,

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

§ Introduction Blood is a unique tissue; why? What kind of tissue? Fig

CO An RBC, WBCs, and four platelets (SEM)

18-5 § Functions of Circulatory System Transport –O 2, CO 2, nutrients, wastes, hormones, and heat Protection –WBCs, antibodies, and platelets Regulation –fluid regulation, buffering, body temp.

§ Two Components of Blood Adults have 4-6 L of blood 1.Plasma– 55% of total volume Including— 2.Cellular (formed) elements— 45% Including— How to separate these two components? (see next slide Fig. 18.2) 18-6

Figure 18.2 Hematocrit-- The percentage of the total blood volume that is occupied by __________ (see next slide) 18-7

Cellular elements 46%) Plasma = 55% of whole blood “Buffy coat” <1% A. Platelets B. WBCs C. Red blood cells of whole blood 18-8 Assuming this tube contains a patient’s blood after centrifugation, what’s his/her blood hematocrit?

§ Seven Kinds of Formed Elements in Blood—

Formed Elements of Blood Erythrocytes (RBCs) 2.Platelets 3.Leukocytes (WBCs) A. Granulocytes— Neutrophils (no. 3) Eosinophils (no. 4) Basophils (no. 5) B. Agranulocytes— Lymphocytes (no. 6) Monocytes (no. 7)

§ Blood Plasma (top layer) Including– Table 18.2 (page 687) 1.Water (90% by weight)-- Most abundant molecule in the plasma Function: 2.Electrolytes (Ions)– What: sodium ions, … Function: 3.Plasma proteins (8%)– (details next slide) 4.Others (2%)– Nutrients,

§ Plasma proteins (top layer) A.Albumins (60% of plasma proteins)– Functions— transport molecules, the major contributor of osmotic pressure and blood viscosity etc. B.Globulins (36%)– (alpha, beta and gamma) Functions– transport molecules, blood clotting factors, gamma-- antibodies C.Fibrinogen (4%)– becomes fibrin, the major blood-clotting factor Where are plasma proteins formed? 18-12

18-13 § 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)

Fig Starvation and Plasma Protein Deficiency—Ascites and Kwashiorkor 18-14

18-15 Disc-shaped cell with thick rim –7.5  M diameter and 2.0  m thick at rim –Blood types determined by surface glycoprotein and glycolipids –cytoskeletal proteins (spectrin and actin) give membrane durability; importance: –Fig a and c § Red Blood Cells (RBCs) or Erythrocytes

Figure 18.4a Fig. 18.4a

Figure 18.4c A Transmission Electron Microscope picture.

18-18 § Erythrocytes (RBCs) Function Gas transport - major function –increased surface area/volume ratio due to ________ shape –98% of cytoplasm is hemoglobin (Hb) O 2 delivery to tissue and CO 2 transport to lungs Carbonic anhydrase (CAH) in RBC –produces carbonic acid from CO 2 and water –important role in gas transport and pH balance

18-19 § 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 O 2 ; where? –How many in 1 Hb?

18-20 § 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

18-21 § Hemopoiesis 1.Adult produces 400 billion platelets, 200 billion RBCs and 10 billion WBCs every day 2.Hemopoietic tissues produce blood cells: A.Fetal life-- yolk sac produces stem cells, migrating to Bone marrow, liver, spleen, thymus B.(at birth) liver stops producing blood cells at birth C.spleen remains involved with Lymphocytes production; Lymphoid hemopoiesis– where? Thymus etc. D.red bone marrow pluripotent stem cells, why? myeloid hemopoiesis produces RBCs, WBCs and platelets

18-22 Our focus

18-23 § 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)

18-24 § Erythrocyte Production (2) C. Erythroblasts-- multiply and synthesize hemoglobin –Discard nucleus to form a reticulocyte D. Reticulocytes— Name? –Characteristics: E. Mature RBCs --

§ 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? 18-25

18-26 § Iron and Erythropoiesis (Fig. 18.7) Iron - key nutritional requirement, why? –Lost through urine, feces, and bleeding –requires dietary consumption of iron, ferric (Fe 3+ ) and ferrous (Fe 2+ ) ions; Steps: 1.converts Fe 3+ to absorbable Fe 2+, where? 2.G-I tract— Gastroferritin binds Fe 2+ 3.In blood-- absorbed into blood and binds to Transferrin for transport 4.Liver-- Apoferritin binds Fe 2+ to create ferritin for storage Fig (iron metabolism)

18-27 Good/excellent sources of iron: ?

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

18-29 Other Needs for Erythropoiesis Vitamin B 12 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

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

18-31 § Erythrocyte Homeostasis (2) Stimuli for erythropoiesis –low levels O 2; in Tibet, Himalaya –increase in oxygen consumption –less lung tissue available (emphysema) –All these factors contribute to secondary polycythemia (details later)

18-32 § Erythrocytes Recycle/Disposal Macrophages in spleen, liver, & red bone marrow 1.Digest mem. fragment & separate heme from globin; Globins into free _______ (into blood) 2.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 and x

Fig Life & Death of RBCs Fate of RBC— Life span– Where are RBCs’ final demise? 18-33

Summary of RBC Life Cycle 18-34

18-35 § 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)...

18-36 § 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

18-37 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 blood pressure drops)– heart failure

18-38 § 3. Sickle-Cell Disease 1.Hereditary Hb ‘defect’; caused by recessive allele modifies hemoglobin structure (HbS) –sickle-cell trait - heterozygous for HbS;(HbA/HbS) –sickle-cell disease - ______________ for HbS 2.Details Fig –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)

18-39 Sickle-Cell Diseased Erythrocyte Fig

Muddiest points of this chapter? 18-40