Blood

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Blood Chapter 17
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Blood Characteristics
Stats Connective tissue Volume 4-6L pH
7.35-7.45 Temp 38oC or 100.4 oF
Components Plasma 55 Erythrocytes
45 Leukocytes/Platelets - lt1
Functions Transport of hormone, gases,
nutrients, etc Regulation of pH, body temp,
water balance Protection from blood loss and
infection
Figure 17.1
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Plasma

• Plasma the liquid component of blood
• Components
• Water 90 of volume
• Plasma proteins 8 of volume
• Most produced by liver
• Albumin most abundant protein (60), a
  transport protein
• Globulins (36) transport proteins and
  antibodies
• Fibrinogen (4) clotting protein
• Nonprotein solutes
• Nitrogenous wastes
• Electrolytes
• Respiratory gases
• Hormones

Table 17.1
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Formed Elements

• Formed Elements the cellular components of
  blood
• Erythrocytes- red blood cells
• Leukocytes white blood cells
• Thrombocytes - platelets

Figure 17.2
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Erythrocytes

• Erythrocytes red blood cells
• Number 5M/ µL
• Diameter 7.5 µm
• Shape biconcave, increases SA
• Anucleate lack a nucleus at maturity
• Functions oxygen and carbon dioxide transport

Figure 17.3
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Hemoglobin

• Hemoglobin (Hb) - Protein composing 97 of RBC
  volume
• Globin amino acid-based portion with 2 alpha
  chains,2 beta chains
• Heme pigment portion with a central Iron atom.
  4, one per globin chain
• 4 heme 4 oxygen x 250M Hb/RBC 1B
  oxygen/RBC!
• Variations oxyhemoglobin, deoxyhemoglobin,
  carbaminohemoglobin

Figure 17.4
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Erythropoeisis
Hematopoiesis blood cell formation, occurs in
red bone marrow Erythropoiesis red blood cell
production - all blood cells arise from a
common stem cell, a hemocytoblast - after Hb
accumulates, the nucleus and organelles beak
down - Now reticulocytes, they enter the
bloodstream and become mature RBCs
Erythropoietin (EPO) hormone that triggers RBC
production
Figure 17.5
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Regulating Erythropoesis

1. Low blood oxygen levels triggers erythropoietin
   (EPO) release from the kidneys
2. EPO causes activity of red bone marrow
3. RBC count rises
4. Blood oxygen levels rise, inhibiting EPO release

Raw Materials amino acids, lipids,
carbohydrates, Iron, and vitamin B
Figure 17.6
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Erythrocyte Breakdown

• Lifespan circulate for 100 - 120 days
• Breakdown RBCs engulfed by macrophages in
  liver, spleen, and bone marrow
• Hemoglobin breakdown
• Hemoglobin is split into heme and globin
• Globins amino acids are recycled to the blood
• Hemes iron is stored in the liver for future
  use
• Hemes pigment, now bilirubin, is used in bile
  production

Figure 17.7
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Erythrocyte Disorders
Anemia any condition leading to a lowered
oxygen carrying capacity of the blood -
Hemorrhagic anemia due to blood loss -
Hemolytic anemia due to RBC rupture -
Iron-deficiency anemia unable to build RBCs -
Sickle-cell anemia a genetic mutation leading
to malformed Hb Polycythemia an abnormally high
RBC count, 6 M cells/µL, resulting from bone
marrow cancer or high elevations
Figure 17.8
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Leukocytes

• Leukocytes white blood cells
• Number 5,000-10,000 cells/µL
• Possess nuclei and organelles
• Function immune responses
• Diapedesis ability of WBCs to exit
  capillaries and enter tissues
• Leukocytosis WBC count gt 11,000 cells/µL, a
  sign of infection

Remembering WBC count Never Let Monkeys Eat
Bananas
Figure 17.9
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Leukocytes
Granulocytes WBCs with cytoplasmic granules -
Neutrophils, Eosinophils, and Basophils Agranulocy
tes WBCs without granules - Lymphocytes and
Monocytes
Figure 17.10
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Neutrophils

• Neutrophils
• Most abundant leukocyte, 50-70 of WBCs, count
  rises during bacterial infection
• Function phagocytes of bacteria, fungi, etc.
• First responders to a site of inflammation
• Multilobed nucleus
• Granules contain enzymes and antimicrobial
  proteins

Figure 17.10a
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Eosinophils

• Eosinophils
• 2-4 of WBCs, count rises during parasitic
  infection
• two-lobed nucleus
• granules contain digestive enzymes specific to
  parasitic worms

Figure 17.10b
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Basophils

• Basophils
• Rarest leukocyte, 0.5-1 of WBCs
• Granules contain histamine, an inflammatory
  chemical
• Play a role in allergic reactions

Figure 17.10c
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Lymphocytes

• Lymphocytes
• 25-45 of WBCs
• Large nucleus and little cytoplasm
• Many located outside vessels, in lymph nodes,
  spleen, etc.
• Two main types
• - T cells target virally-infected cells
• - B cells make antibodies

Figure 17.10d
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Monocytes

• Monocytes
• 3-8 of WBCs
• Largest WBC, 14-24 µm
• Migrate into tissues where they become
  macrophages, long-lived phagocytes

Figure 17.10e
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Leukopoiesis

• Leukopoiesis the production of WBCs
• all arise from hemocytoblast stem cell
• Lymphoid cell line produces only lymphocytes
• Myeloid cell line produces all other WBCs and
  RBCs
• Stimulated by inflammatory chemicals

Figure 17.11
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Platelets

• Platelets
• Cytoplasmic fragments of marrow cells called
  megakaryocytes
• Promote clotting by forming a temporary plug in
  a damaged vessel wall
• Only circulate for 10 days, are constantly
  produced

Figure 17.12
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Hemostasis

• Hemostasis the stoppage of bleeding
• Occurs in 3 steps
• Vascular Spasm constriction of the damaged
  vessel to limit blood loss
• Platelet plug formation platelets stick to the
  exposed collagen fibers of a damaged blood
  vessel, become sticky, and chemically recruit
  more platelets to form a plug
• Coagulation blood clotting, which occurs in
  three steps

Figure 17.13a
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Coagulation

• Coagulation a complex chemical process
  involving calcium and a balance of procoagulants
  and anticoagulants in 3 steps
• Forming Prothrombin Activator must form this
  enzyme to catalyze step 2
• Intrinsic pathway slower, all components from
  within blood
• Extrinsic pathway faster, uses TF from damaged
  tissue
• Thrombin formation Prothrombin activator
  converts prothrombin to thrombin
• Fibrin formation Thrombin converts soluble
  fibrinogen into solid fibrin strands, which stick
  to form the clot

Figure 17.13b
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Hemostasis
Clot retraction the tightening of a clot
within 30-60 minutes Fibrinolysis the
breakdown of a blood clot, performed by plasmin
enzyme Anticoagulants prevent overclotting by
deactivating thrombin. Exs - Antithrombin III
and Heparin
Figure 17.14
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Disorders of Hemostasis

• Clotting Disorders
• Thrombus a blood clot in an undamaged vessel
• Embolus a blood clot floating freely in the
  bloodstream
• Embolism a circulating blood clot that has
  blocked a vessel
• Aspirin and Heparin are used to prevent and
  treat these clots
• Bleeding Disorders
• Hemophilia various hereditary conditions
  resulting in the lack of certain procoagulants
• Thrombocytopenia low platelet levels

Figure 17.14
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Blood Groups
ABO blood groups blood types according to
proteins on the RBC cell surfaces Genes A,B,
and O genes encode for A, B, and O proteins .
Every person possesses two of these genes
Table 17.4
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Blood Groups
Agglutinogens the proteins on the RBC
surfaces Agglutinins antibodies specific to the
agglutinogens not possessed by an individual
Agglutination the clumping of cells that occur
when agglutinins bind to their specific
agglutinogens
Table 17.4
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Blood Groups

• Blood Typing
• Split a blood sample into two halves
• Mix one half with a serum of A agglutinins and
  the other with a serum of B agglutinins
• Any sample that clumps (agglutinates) shows you
  that specific agglutinogen is present on the RBC
  surfaces

Figure 17.15
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Blood Groups
Blood Type Genes Agglutinins Donate To Receive From
A
B
AB
O
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Blood Groups

• Rh blood groups
• Classifies blood type as or , based on the
  presence or absence of an RBC surface protein
• , a positive blood type
• , - a positive blood type
• -, - a negative blood type
• An Rh person can safely receive Rh- blood, but
  an Rh- person receiving Rh blood will cause
  agglutinationWhy?
• Erythroblastosis Fetalis when an Rh- mothers
  immune system rejects the Rh blood of her fetus.
  Does not happen if it her first pregnancyWhy?