Presentation on theme: "Ch. 18 Blood-- Study Guide 1.Critically read pp. 683-704 before “Leukocyte life cycle” section 2.Comprehend Terminology (the text in bold) 3.Study-- Figure."— Presentation transcript:
Ch. 18 Blood-- Study Guide 1.Critically read pp. 683-704 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, 17-20 –True or False– 1, 2, 3, 5, 8, 9 –Testing Your Comprehension--1, 2, 3 18-1
Chapter 18– Blood The study of blood is called ___________ A-- Herpetology B-- Hematology C-- Homeostasis D-- Hercules 18-2
§ 18.1--Introduction Blood is a unique tissue; why? What kind of tissue? Fig. 18.0 18-3
CO 18 18-4 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 = @45% 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— 18-9 1 4 3 2 5 7 6
Formed Elements of Blood 18-10 1.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,... 18-11
§ 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. 18.3--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. 18.4 a and c § 18.2--Red Blood Cells (RBCs) or Erythrocytes
Figure 18.4a 18-16 Fig. 18.4a
Figure 18.4c 18-17 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. 18.7 (iron metabolism)
18-27 Good/excellent sources of iron: ?
In-class activity Give one disease related to low plasma proteins. Explain your answer. 18-28
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 -- 2. Others (next slide) Results: –EPO production stimulates bone marrow –RBC count in 3 - 4 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. 18.9 and x
Fig. 18.9 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. 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)