Ch 20: The BloodCh 20: The Blood
Discuss the composition of blood including the functions of the various components
Explain the anatomy and functions of the red blood cells, including a description of blood typing
Discuss the types of white blood cells found in the blood and give the functions of each
Give a brief accounting of the platelets
Review hemopoiesis, including RBC and leukocyte formation
Functions of Blood
Distribution - nutrients, wastes, hormones, gases, etc.
Self-sealing – hemostasis
Disease/ infection fighting
Blood = connective tissue
extracellularmatrix:Plasma
specialized cells:
(= Formed elements)
RBCs
WBCs
Plateletscolor ?volume ?
Plasma CompositionPlasma Composition
Water 92%
Plasma proteins 7% Other solutes
1%
Transports organic and inorganic molecules, formed elements, and heat
Plasma ProteinsPlasma Proteins
Albumin (60%) Major contributor to osmotic concentration of plasma. Transport of lipids and steroid hormones
Globulins (35%) Transport ions, hormones, lipids; immune function
Fibrinogen (4%) Essential component of clotting system (conversion to insoluble fibrin)
Regulatory proteins (< 1%) ????
Other Solutes
Electrolytes: Normal extracellular fluid ion composition (????)
Organic nutrients: glucose, FA, AA
Organic wastes: urea, bilirubin
Difference between Plasma and Interstitial Fluid :
Plasma has more:Plasma has more: Dissolved O2 O2 diffuses out into tissue Dissolved proteins (too big to cross caps.)
» Albumins » Globulins
– globulins
– and globulins
» Fibrinogen
Similar concentration: Salts & small molecules
serum = plasma -serum = plasma -
Difference between
plasma and serum?
. . . . 2 more things:
Most plasma proteins are made in liver. Exception: ?
Lipoproteins = particles containing lipids (cholesterol & triglycerids) and proteins (albumins & globulins)
Formed ElementsFormed Elements
Red and White Blood Cells
Platelets
Platelets WBCs
RBCs
.1%
99.9%
Formed Elements cont.Formed Elements cont.Why whitewhite blood cells???
RBCs = Erythrocytes
Measured by hematocrit or PCV
Most abundant blood cell: 1000 RBCs/1 WBC
Contain hemoglobin, carry O2
Very regular shape - biconcave discs
Anucleate: Lifespan ~ 120 days replacement rate ~ 3 mio RBCs / sec
Structure of Hemoglobin (Hb)Structure of Hemoglobin (Hb)
Fe ion in heme group reversibly binds O2
How many oxygen
molecules can 1
Hb molecule
carry?
ABO & Rh ABO & Rh Blood TypesBlood Types
Blood groups (types) based on specific Blood groups (types) based on specific RBC surface antigens (= proteins)RBC surface antigens (= proteins)
> 30 common varieties of antigens > 30 common varieties of antigens known. Most important ABO & Rhknown. Most important ABO & Rh
blood type ?
ABO Blood typing: ABO Blood typing: 4 combinations possible4 combinations possible
A surface antigen = blood type A B surface antigen = blood type B both surface antigens = type AB neither surface antigen = type O
Rh surface antigen = + blood type no Rh antigen = negative blood type
. . . 2 - 8 months after birth:
Anti-A and anti-B antibodies can be Anti-A and anti-B antibodies can be formed in plasma !formed in plasma !
normally NO anti Rh present
Transfusion ReactionTransfusion of incompatible blood can be fatal!
Universal Donor vs. Universal Donor vs. Universal RecipientUniversal Recipient
Only for emergencies - must be given slowly !
Clinical Brief
Anemia: p. 536
Reduced oxygen carrying ability of blood. Causes??
Polycythemia: Erythrocytosis: excessive increase in RBCsPolycythemia vera:
Blood Doping: p. 545
Via direct transfusion, orEPO use
WBCs = LeukocytesWBCs = Leukocytes
Quantity and type determined by differential WBC count
Circulating WBCs are only a small fraction of total WBCs. Most are located in ?
Diapedesis
Chemotaxis
Granulocytes and Agranulocytes
Neutrophil (= PMN)Neutrophil (= PMN)
Up to ~ 70% (~ 2/3) of circulating WBCs
Cytoplasm packed with pale granules containing lysosomal enzymes
phagocytic
EosinophilEosinophil
~ 2% - 4% of circulating WBCs
Granules stain with eosin
Increased in allergies and parasitic infections
BasophilBasophil
< 1% of circulating WBCs
Granules stain with basic dyes and contain histamine
Discharge of histamine promotes inflammation at site of injury (Similar to mast cells)
MonocyteMonocyte
~ 2% - 8% of circulating WBCs Large kidney shaped nucleus In tissue called Macrophage
LymphocytesLymphocytes
~ 20% - 30% of circulating WBCs Relatively small (slightly larger than RBCs) Large round nucleus B, T, NK
Platelets = ThrombocytesPlatelets = Thrombocytes
Cell fragments of Megakaryocytes
(~ 4,000 thrombocytes per Megakaryocyte)
~ 160 m
Lifespan ~ 12 days
involved in blood clotting
Abnormal Blood Cell Counts
Leukopenia < 2,500/ L (normal 6000 – 9000)
Leukocytosis > 30,000/ L
Thrombocytopenia: < 80,000/ L (normal ~ 350,000)
Thrombocytosis: > 1,000,000/ L
Also
Lymphopenia vs. _____________
_________vs. Neutrophilia
Hemopoiesis = Blood Cell FormationHemopoiesis = Blood Cell Formation
Hemocytoblasts: One type of stem cell for all blood cells
In red bone marrowIn red bone marrow
. . . then differentiation into 4 types of progenitor stem cells:
Erythroblast
Myeloblast
Monoblast
Lymphoblast
Fig 20.8
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