Ch. 18 Blood-- Study Guide 1. Critically read pp. 683-704 before
“Leukocyte life cycle” section2. 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
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Chapter 18– Blood
The study of blood is called ___________
A-- Herpetology
B-- Hematology
C-- Homeostasis
D-- Hercules
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§ 18.1--Introduction
• Blood is a unique tissue; why?
• What kind of tissue?
Fig. 18.0
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CO 18
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An RBC, WBCs, and four platelets (SEM)
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§ Functions of Circulatory System
• Transport– O2, CO2, nutrients, wastes, hormones, and
heat
• Protection– WBCs, antibodies, and platelets
• Regulation – fluid regulation, buffering, body temp.
§ Two Components of BloodAdults 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)
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Figure 18.2
Hematocrit-- The percentage of the total blood volume that is occupied by __________ (see next slide)
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Cellular elements (= @ 46%)
Plasma = 55% of whole blood
“Buffy coat”<1%
A. Platelets
B. WBCs
C. Red blood cells =@45% of whole blood
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Assuming this tube contains a patient’s blood after centrifugation, what’s his/her blood hematocrit?
§ Seven Kinds of Formed Elements in Blood—
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1
4
3
2
5
7
6
Formed Elements of Blood
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1. Erythrocytes (RBCs)2. Platelets3. 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, . . .
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§ 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?
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§ 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
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• 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
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Fig. 18.4a
Figure 18.4c
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A Transmission Electron Microscope picture.
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§ 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
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§ 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?
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§ 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
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§ Hemopoiesis1. 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
18-22Our focus
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§ 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 organellesA. Pluripotent stem cells become committed
cells – B. erythrocyte colony forming unit (ECFU)
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§ 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
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§ 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:
1.converts Fe3+ to absorbable Fe2+, where?
2.G-I tract— Gastroferritin binds Fe2+
3.In blood-- absorbed into blood and binds to Transferrin for transport
4.Liver-- Apoferritin binds Fe2+ to create ferritin for storage
Fig. 18.7 (iron metabolism)
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Good/excellent sources of iron: ?
In-class activity
• Give one disease related to low plasma proteins. Explain your answer.
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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
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§ 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
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§ 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)
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§ Erythrocytes Recycle/DisposalMacrophages 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?
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Summary of RBC Life Cycle
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§ 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) . . .
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§ 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
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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
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§ 3. Sickle-Cell Disease1. 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)
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Sickle-Cell Diseased Erythrocyte
Fig. 18.10
Muddiest points of this chapter?
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