Blood

1
Chapter 17

• Blood

2
Overview of Blood Circulation

• Blood leaves the heart via arteries that branch
  repeatedly until they become capillaries
• Oxygen (O2) and nutrients diffuse across
  capillary walls and enter tissues
• Carbon dioxide (CO2) and wastes move from tissues
  into the blood

3
Overview of Blood Circulation

• Oxygen-deficient blood leaves the capillaries and
  flows in veins to the heart
• This blood flows to the lungs where it releases
  CO2 and picks up O2
• The oxygen-rich blood returns to the heart

4
Composition of Blood

• Blood is the bodys only fluid tissue
• It is composed of liquid plasma and formed
  elements
• Formed elements include
• Erythrocytes, or red blood cells (RBCs)
• Leukocytes, or white blood cells (WBCs)
• Platelets
• Hematocrit the percentage of RBCs out of the
  total blood volume

5
Components of Whole Blood
Figure 17.1
6
Physical Characteristics and Volume

• Blood is a sticky, opaque fluid with a metallic
  taste
• Color varies from scarlet to dark red
• The pH of blood is 7.357.45
• Blood accounts for approximately 8 of body
  weight

7
Functions of Blood

• Blood performs a number of functions dealing
  with
• Substance distribution
• Regulation of blood levels of particular
  substances
• Body protection

8
Distribution

• Blood transports
• Oxygen from the lungs and nutrients from the
  digestive tract
• Metabolic wastes from cells to the lungs and
  kidneys for elimination
• Hormones from endocrine glands to target organs

9
Regulation

• Blood maintains
• Appropriate body temperature by absorbing and
  distributing heat
• Normal pH in body tissues using buffer systems
• Adequate fluid volume in the circulatory system

10
Protection

• Blood prevents blood loss by
• Activating plasma proteins and platelets
• Initiating clot formation when a vessel is broken
• Blood prevents infection by
• Synthesizing and utilizing antibodies
• Activating complement proteins
• Activating WBCs to defend the body against
  foreign invaders

11
Blood Plasma

• Blood plasma contains over 100 solutes,
  including
• Proteins albumin, globulins, clotting proteins,
  and others
• Lactic acid, urea, creatinine
• Organic nutrients glucose, carbohydrates, amino
  acids
• Electrolytes sodium, potassium, calcium,
  chloride, bicarbonate
• Respiratory gases oxygen and carbon dioxide

12
Formed Elements

• Erythrocytes, leukocytes, and platelets make up
  the formed elements
• Only WBCs are complete cells
• RBCs have no nuclei or organelles, and platelets
  are just cell fragments
• Most formed elements survive in the bloodstream
  for only a few days
• Most blood cells do not divide but are renewed by
  cells in bone marrow

13
Erythrocytes (RBCs)

• Biconcave discs, anucleate, essentially no
  organelles
• Filled with hemoglobin (Hb), a protein that
  functions in gas transport
• Contain the plasma membrane protein spectrin and
  other proteins that
• Give erythrocytes their flexibility
• Allow them to change shape as necessary

14
Erythrocytes (RBCs)
Figure 17.3
15
Components of Whole Blood
Figure 17.2
16
Erythrocytes (RBCs)

• Erythrocytes are an example of the
  complementarity of structure and function
• Structural characteristics contribute to its gas
  transport function
• Biconcave shape has a huge surface area relative
  to volume
• Erythrocytes are more than 97 hemoglobin
• ATP is generated anaerobically, so the
  erythrocytes do not consume the oxygen they
  transport

17
Erythrocyte Function

• RBCs are dedicated to respiratory gas transport
• Hb reversibly binds with oxygen and most oxygen
  in blood is bound to Hb
• Hb is composed of the protein globin (4 chains),
  each bound to a heme group
• Each heme group bears an atom of iron, which can
  bind to one oxygen molecule
• Each Hb molecule can transport four molecules of
  oxygen

18
Structure of Hemoglobin
Figure 17.4
19
Hemoglobin (Hb)

• Oxyhemoglobin Hb bound to oxygen
• Oxygen loading takes place in the lungs
• Deoxyhemoglobin Hb after oxygen diffuses into
  tissues (reduced Hb)
• Carbaminohemoglobin Hb bound to carbon dioxide
• Carbon dioxide loading takes place in the tissues

20
Production of Erythrocytes

• Hematopoiesis blood cell formation
• Hematopoiesis occurs in the red bone marrow of
  the
• Axial skeleton and girdles
• Epiphyses of the humerus and femur
• Hemocytoblasts give rise to all formed elements

21
Production of Erythrocytes Erythropoiesis

• A hemocytoblast is transformed into a
  proerythroblast
• Proerythroblasts develop into early erythroblasts
• Erythroblasts become normoblasts
• Normoblasts become reticulocytes
• Reticulocytes then become mature erythrocytes

22
Production of Erythrocytes Erythropoiesis
Figure 17.5
23
Regulation and Requirements for Erythropoiesis

• Circulating erythrocytes the number remains
  constant and reflects a balance between RBC
  production and destruction
• Too few RBCs leads to tissue hypoxia
• Too many RBCs causes undesirable blood viscosity
• Erythropoiesis is hormonally controlled and
  depends on adequate supplies of iron, amino
  acids, and B vitamins

24
Hormonal Control of Erythropoiesis

• Erythropoietin (EPO) release by the kidneys is
  triggered by
• Hypoxia due to decreased RBCs
• Decreased oxygen availability
• Increased tissue demand for oxygen
• Enhanced erythropoiesis increases the
• RBC count in circulating blood
• Oxygen carrying ability of the blood

25
Erythropoietin Mechanism
Imbalance
Start
Homeostasis Normal blood oxygen levels
Stimulus Hypoxia due to decreased RBC
count, decreased amount of hemoglobin, or
decreased availability of O2
Imbalance
Increases O2-carrying ability of blood
Reduces O2 levels in blood
Kidney (and liver to a smaller extent) releases
erythropoietin
Enhanced erythropoiesis increases RBC count
Erythropoietin stimulates red bone marrow
Figure 17.6
26
Dietary Requirements of Erythropoiesis

• Erythropoiesis requires
• Proteins, lipids, and carbohydrates
• Iron, vitamin B12, and folic acid
• The body stores iron in Hb (65), the liver,
  spleen, and bone marrow
• Intracellular iron is stored in protein-iron
  complexes such as ferritin and hemosiderin
• Circulating iron is loosely bound to the
  transport protein transferrin

27
Fate and Destruction of Erythrocytes

• The life span of an erythrocyte is 100120 days
• Old RBCs become rigid and fragile, and their Hb
  begins to degenerate
• Dying RBCs are engulfed by macrophages
• Heme and globin are separated and the iron is
  salvaged for reuse

28
Fate and Destruction of Erythrocytes

• Heme is degraded to a yellow pigment called
  bilirubin
• The liver secretes bilirubin into the intestines
  as bile
• The intestines metabolize it into urobilinogen
• This degraded pigment leaves the body in feces

29
Fate and Destruction of Erythrocytes

• Globin is metabolized into amino acids and is
  released into the circulation
• Hb released into the blood and phagocytized

30
Low O2 levels in blood stimulate kidneys to
produce erythropoietin.
1
Erythropoietin levels rise in blood.
2
Erythropoietin and necessary raw materials in
blood promote erythropoiesis in red bone marrow.
3
New erythrocytes enter bloodstream function
about 120 days.
4
Aged and damaged red blood cells are engulfed
by macrophages of liver, spleen, and bone marrow
the hemoglobin is broken down.
5
Hemoglobin
Globin
Heme
Bilirubin
Amino acids
Iron stored as ferritin, hemosiderin
Iron is bound to transferrin and released to
blood from liver as needed for erythropoiesis
Bilirubin is picked up from blood by liver,
secreted into intestine in bile, metabolized to
stercobilin by bacteria and excreted in feces
Circulation
Food nutrients, including amino acids, Fe,
B12, and folic acid are absorbed from
intestine and enter blood
Raw materials are made available in blood for
erythrocyte synthesis.
6
Figure 17.7
31
Low O2 levels in blood stimulate kidneys to
produce erythropoietin.
1
Figure 17.7
32
Low O2 levels in blood stimulate kidneys to
produce erythropoietin.
1
Erythropoietin levels rise in blood.
2
Figure 17.7
33
Low O2 levels in blood stimulate kidneys to
produce erythropoietin.
1
Erythropoietin levels rise in blood.
2
Erythropoietin and necessary raw materials in
blood promote erythropoiesis in red bone marrow.
3
Figure 17.7
34
Low O2 levels in blood stimulate kidneys to
produce erythropoietin.
1
Erythropoietin levels rise in blood.
2
Erythropoietin and necessary raw materials in
blood promote erythropoiesis in red bone marrow.
3
New erythrocytes enter bloodstream function
about 120 days.
4
Figure 17.7
35
Low O2 levels in blood stimulate kidneys to
produce erythropoietin.
1
Erythropoietin levels rise in blood.
2
Erythropoietin and necessary raw materials in
blood promote erythropoiesis in red bone marrow.
3
New erythrocytes enter bloodstream function
about 120 days.
4
Aged and damaged red blood cells are engulfed
by macrophages of liver, spleen, and bone marrow
the hemoglobin is broken down.
5
Hemoglobin
Figure 17.7
36
Hemoglobin
Globin
Heme
Figure 17.7
37
Hemoglobin
Globin
Heme
Amino acids
Figure 17.7
38
Hemoglobin
Globin
Heme
Bilirubin
Amino acids
Iron stored as ferritin, hemosiderin
Figure 17.7
39
Hemoglobin
Globin
Heme
Bilirubin
Amino acids
Iron stored as ferritin, hemosiderin
Figure 17.7
40
Hemoglobin
Globin
Heme
Bilirubin
Amino acids
Iron stored as ferritin, hemosiderin
Iron is bound to transferrin and released to
blood from liver as needed for erythropoiesis
Figure 17.7
41
Hemoglobin
Globin
Heme
Bilirubin
Amino acids
Iron stored as ferritin, hemosiderin
Iron is bound to transferrin and released to
blood from liver as needed for erythropoiesis
Bilirubin is picked up from blood by liver,
secreted into intestine in bile, metabolized to
stercobilin by bacteria and excreted in feces
Figure 17.7
42
Hemoglobin
Globin
Heme
Bilirubin
Amino acids
Iron stored as ferritin, hemosiderin
Iron is bound to transferrin and released to
blood from liver as needed for erythropoiesis
Bilirubin is picked up from blood by liver,
secreted into intestine in bile, metabolized to
stercobilin by bacteria and excreted in feces
Circulation
Food nutrients, including amino acids, Fe,
B12, and folic acid are absorbed from
intestine and enter blood
Figure 17.7
43
Hemoglobin
Globin
Heme
Bilirubin
Amino acids
Iron stored as ferritin, hemosiderin
Iron is bound to transferrin and released to
blood from liver as needed for erythropoiesis
Bilirubin is picked up from blood by liver,
secreted into intestine in bile, metabolized to
stercobilin by bacteria and excreted in feces
Circulation
Food nutrients, including amino acids, Fe,
B12, and folic acid are absorbed from
intestine and enter blood
Raw materials are made available in blood for
erythrocyte synthesis.
6
Figure 17.7
44
Erythrocyte Disorders

• Anemia blood has abnormally low oxygen-carrying
  capacity
• It is a symptom rather than a disease itself
• Blood oxygen levels cannot support normal
  metabolism
• Signs/symptoms include fatigue, paleness,
  shortness of breath, and chills

45
Anemia Insufficient Erythrocytes

• Hemorrhagic anemia result of acute or chronic
  loss of blood
• Hemolytic anemia prematurely ruptured RBCs
• Aplastic anemia destruction or inhibition of
  red bone marrow

46
Anemia Decreased Hemoglobin Content

• Iron-deficiency anemia results from
• A secondary result of hemorrhagic anemia
• Inadequate intake of iron-containing foods
• Impaired iron absorption
• Pernicious anemia results from
• Deficiency of vitamin B12
• Lack of intrinsic factor needed for absorption of
  B12

47
Anemia Abnormal Hemoglobin

• Sickle-cell anemia results from a defective
  gene coding for an abnormal Hb
• Abnormal Hb has a single amino acid substitution
• This defect causes RBCs to become sickle-shaped
  in low oxygen situations

48
Polycythemia

• Polycythemia excess RBCs that increase blood
  viscosity
• Three main polycythemias are
• Polycythemia vera
• Secondary polycythemia
• Blood doping

49
Leukocytes (WBCs)

• Leukocytes, the only blood components that are
  complete cells
• Are less numerous than RBCs
• Make up 1 of the total blood volume
• Can leave capillaries via diapedesis
• Move through tissue spaces
• Leukocytosis WBC count over normal amount
• Normal response to bacterial or viral invasion

50
Percentages of Leukocytes
Figure 17.9
51
Granulocytes

• Granulocytes neutrophils, eosinophils, and
  basophils
• Contain cytoplasmic granules that stain
  specifically (acidic, basic, or both) with
  Wrights stain
• Are larger and usually shorter-lived than RBCs
• Have lobed nuclei
• Are all phagocytic cells

52
Neutrophils

• Neutrophils have two types of granules that
• Take up both acidic and basic dyes
• Give the cytoplasm a lilac color
• Contain peroxidases, hydrolytic enzymes, and
  defensins (antibiotic-like proteins)
• Neutrophils are our bodys bacteria slayers

53
Eosinophils

• Eosinophils account for 14 of WBCs
• Have red to crimson (acidophilic) large, coarse,
  lysosome-like granules
• Lead the bodys counterattack against parasitic
  worms
• Lessen the severity of allergies by phagocytizing
  immune complexes

54
Basophils

• Account for 0.5 of WBCs and
• Are functionally similar to mast cells
• Have large, purplish-black (basophilic) granules
  that contain histamine
• Histamine inflammatory chemical that acts as a
  vasodilator and attracts other WBCs
  (antihistamines counter this effect)

55
Agranulocytes

• Agranulocytes lymphocytes and monocytes
• Lack visible cytoplasmic granules
• Are similar structurally, but are functionally
  distinct and unrelated cell types
• Have spherical (lymphocytes) or kidney-shaped
  (monocytes) nuclei

56
Lymphocytes

• Account for 25 or more of WBCs and
• Are found mostly enmeshed in lymphoid tissue
  (some circulate in the blood)
• There are two types of lymphocytes T cells and B
  cells
• T cells function in the immune response
• B cells give rise to plasma cells, which produce
  antibodies

57
Monocytes

• Monocytes account for 48 of leukocytes
• They are the largest leukocytes
• They leave the circulation, enter tissue, and
  differentiate into macrophages

58
Macrophages

• Macrophages
• Are highly mobile and actively phagocytic
• Activate lymphocytes to mount an immune response

59
Leukocytes
Figure 17.10
60
Summary of Formed Elements
Table 17.2.1
61
Summary of Formed Elements
Table 17.2.2
62
Formation of Leukocytes

• All leukocytes originate from hemocytoblasts
• Hemocytoblasts differentiate into myeloid stem
  cells and lymphoid stem cells
• Myeloid stem cells become myeloblasts or
  monoblasts
• Lymphoid stem cells become lymphoblasts
• Myeloblasts develop into eosinophils,
  neutrophils, and basophils
• Monoblasts develop into monocytes
• Lymphoblasts develop into lymphocytes

63
Stem cells
Hemocytoblast
Figure 17.11
64
Stem cells
Hemocytoblast
Myeloid stem cell
Figure 17.11
65
Stem cells
Hemocytoblast
Myeloid stem cell
Committed cells
Myeloblast
Myeloblast
Myeloblast
Figure 17.11
66
Stem cells
Hemocytoblast
Myeloid stem cell
Committed cells
Myeloblast
Myeloblast
Myeloblast
Develop- mental pathway
Promyelocyte
Promyelocyte
Promyelocyte
Promonocyte
Figure 17.11
67
Stem cells
Hemocytoblast
Myeloid stem cell
Committed cells
Myeloblast
Myeloblast
Myeloblast
Develop- mental pathway
Promyelocyte
Promyelocyte
Promyelocyte
Promonocyte
Eosinophilic myelocyte
Neutrophilic myelocyte
Basophilic myelocyte
Figure 17.11
68
Stem cells
Hemocytoblast
Myeloid stem cell
Committed cells
Myeloblast
Myeloblast
Myeloblast
Develop- mental pathway
Promyelocyte
Promyelocyte
Promyelocyte
Promonocyte
Eosinophilic myelocyte
Neutrophilic myelocyte
Basophilic myelocyte
Eosinophilic band cells
Neutrophilic band cells
Basophilic band cells
Figure 17.11
69
Stem cells
Hemocytoblast
Myeloid stem cell
Committed cells
Myeloblast
Myeloblast
Myeloblast
Develop- mental pathway
Promyelocyte
Promyelocyte
Promyelocyte
Promonocyte
Eosinophilic myelocyte
Neutrophilic myelocyte
Basophilic myelocyte
Eosinophilic band cells
Neutrophilic band cells
Basophilic band cells
Monocytes
Eosinophils
Neutrophils
Basophils
(a)
(b)
(c)
(d)
Agranular leukocytes
Granular leukocytes
Figure 17.11
70
Stem cells
Hemocytoblast
Myeloid stem cell
Committed cells
Myeloblast
Myeloblast
Myeloblast
Develop- mental pathway
Promyelocyte
Promyelocyte
Promyelocyte
Promonocyte
Eosinophilic myelocyte
Neutrophilic myelocyte
Basophilic myelocyte
Eosinophilic band cells
Neutrophilic band cells
Basophilic band cells
Monocytes
Eosinophils
Neutrophils
Basophils
(a)
(b)
(c)
(d)
Agranular leukocytes
Granular leukocytes
Some become
Macrophages (tissues)
Figure 17.11
71
Stem cells
Hemocytoblast
Myeloid stem cell
Lymphoid stem cell
Committed cells
Myeloblast
Myeloblast
Myeloblast
Develop- mental pathway
Promyelocyte
Promyelocyte
Promyelocyte
Promonocyte
Eosinophilic myelocyte
Neutrophilic myelocyte
Basophilic myelocyte
Eosinophilic band cells
Neutrophilic band cells
Basophilic band cells
Monocytes
Eosinophils
Neutrophils
Basophils
(a)
(b)
(c)
(d)
Agranular leukocytes
Granular leukocytes
Some become
Macrophages (tissues)
Figure 17.11
72
Stem cells
Hemocytoblast
Myeloid stem cell
Lymphoid stem cell
Committed cells
Myeloblast
Myeloblast
Myeloblast
Lymphoblast
Develop- mental pathway
Promyelocyte
Promyelocyte
Promyelocyte
Promonocyte
Eosinophilic myelocyte
Neutrophilic myelocyte
Basophilic myelocyte
Eosinophilic band cells
Neutrophilic band cells
Basophilic band cells
Monocytes
Eosinophils
Neutrophils
Basophils
(a)
(b)
(c)
(d)
Agranular leukocytes
Granular leukocytes
Some become
Macrophages (tissues)
Figure 17.11
73
Stem cells
Hemocytoblast
Myeloid stem cell
Lymphoid stem cell
Committed cells
Myeloblast
Myeloblast
Myeloblast
Lymphoblast
Develop- mental pathway
Promyelocyte
Promyelocyte
Promyelocyte
Promonocyte
Prolymphocyte
Eosinophilic myelocyte
Neutrophilic myelocyte
Basophilic myelocyte
Eosinophilic band cells
Neutrophilic band cells
Basophilic band cells
Monocytes
Eosinophils
Neutrophils
Basophils
(a)
(b)
(c)
(d)
Agranular leukocytes
Granular leukocytes
Some become
Macrophages (tissues)
Figure 17.11
74
Stem cells
Hemocytoblast
Myeloid stem cell
Lymphoid stem cell
Committed cells
Myeloblast
Myeloblast
Myeloblast
Lymphoblast
Develop- mental pathway
Promyelocyte
Promyelocyte
Promyelocyte
Promonocyte
Prolymphocyte
Eosinophilic myelocyte
Neutrophilic myelocyte
Basophilic myelocyte
Eosinophilic band cells
Neutrophilic band cells
Basophilic band cells
Monocytes
Lymphocytes
Eosinophils
Neutrophils
Basophils
(a)
(b)
(c)
(d)
(e)
Agranular leukocytes
Granular leukocytes
Some become
Macrophages (tissues)
Figure 17.11
75
Stem cells
Hemocytoblast
Myeloid stem cell
Lymphoid stem cell
Committed cells
Myeloblast
Myeloblast
Myeloblast
Lymphoblast
Develop- mental pathway
Promyelocyte
Promyelocyte
Promyelocyte
Promonocyte
Prolymphocyte
Eosinophilic myelocyte
Neutrophilic myelocyte
Basophilic myelocyte
Eosinophilic band cells
Neutrophilic band cells
Basophilic band cells
Monocytes
Lymphocytes
Eosinophils
Neutrophils
Basophils
(a)
(b)
(c)
(d)
(e)
Some become
Agranular leukocytes
Granular leukocytes
Some become
Plasma cells
Macrophages (tissues)
Figure 17.11
76
Leukocytes Disorders Leukemias

• Leukemia refers to cancerous conditions involving
  WBCs
• Leukemias are named according to the abnormal
  WBCs involved
• Myelocytic leukemia involves myeloblasts
• Lymphocytic leukemia involves lymphocytes
• Acute leukemia involves blast-type cells and
  primarily affects children
• Chronic leukemia is more prevalent in older people

77
Leukemia

• Immature WBCs are found in the bloodstream in all
  leukemias
• Bone marrow becomes totally occupied with
  cancerous leukocytes
• The WBCs produced, though numerous, are not
  functional
• Death is caused by internal hemorrhage and
  overwhelming infections
• Treatments include irradiation, antileukemic
  drugs, and bone marrow transplants

78
Platelets

• Platelets are fragments of megakaryocytes
• Platelets function in the clotting mechanism by
  forming a temporary plug that helps seal breaks
  in blood vessels

79
Genesis of Platelets

• The stem cell for platelets is the hemocytoblast
• The sequential developmental pathway is as shown.

Stem cell
Developmental pathway
Hemocytoblast
Megakaryoblast
Promegakaryocyte
Megakaryocyte
Platelets
Figure 17.12
80
Hemostasis

• A series of reactions for stoppage of bleeding
• During hemostasis, three phases occur in rapid
  sequence
• Vascular spasms immediate vasoconstriction in
  response to injury
• Platelet plug formation
• Coagulation (blood clotting)

81
Platelet Plug Formation

• Platelets do not stick to each other or to blood
  vessels
• Upon damage to blood vessel endothelium
  platelets
• With the help of von Willebrand factor (VWF)
  adhere to collagen
• Stick to exposed collagen fibers and form a
  platelet plug
• Release serotonin and ADP, which attract still
  more platelets
• The platelet plug is limited to the immediate
  area of injury

82
Coagulation

• A set of reactions in which blood is transformed
  from a liquid to a gel
• Coagulation follows intrinsic and extrinsic
  pathways
• The final three steps of this series of reactions
  are
• Prothrombin activator is formed
• Prothrombin is converted into thrombin
• Thrombin catalyzes the joining of fibrinogen into
  a fibrin mesh

83
Coagulation
Figure 17.13a
84
Coagulation Pathway to Thrombin

• Prothrombin activator catalyzes the
  transformation of prothrombin to the active
  enzyme thrombin

85
Coagulation Common Pathways to the Fibrin Mesh

• Thrombin catalyzes the polymerization of
  fibrinogen into fibrin
• Insoluble fibrin strands form the structural
  basis of a clot
• Fibrin causes plasma to become a gel-like trap

86
Hemostasis DisordersThromboembolytic Conditions

• Thrombus a clot that develops and persists in
  an unbroken blood vessel
• Thrombi can block circulation, resulting in
  tissue death
• Coronary thrombosis thrombus in blood vessel of
  the heart

87
Hemostasis DisordersThromboembolytic Conditions

• Embolus a thrombus freely floating in the blood
  stream
• Pulmonary emboli can impair the ability of the
  body to obtain oxygen
• Cerebral emboli can cause strokes

88
Prevention of Undesirable Clots

• Substances used to prevent undesirable clots
• Aspirin an antiprostaglandin
• Heparin an anticoagulant used clinically for
  pre- and postoperative cardiac care
• Warfarin used for those prone to atrial
  fibrillation

89
Hemostasis Disorders Bleeding Disorders

• Thrombocytopenia condition where the number of
  circulating platelets is deficient
• Patients show petechiae due to spontaneous,
  widespread hemorrhage
• Caused by suppression or destruction of bone
  marrow (e.g., malignancy, radiation)
• Platelet counts less than 50,000/mm3 is
  diagnostic for this condition
• Treated with whole blood transfusions

90
Hemostasis Disorders Bleeding Disorders

• Inability to synthesize procoagulants by the
  liver results in severe bleeding disorders
• Causes can range from vitamin K deficiency to
  hepatitis and cirrhosis
• Inability to absorb fat can lead to vitamin K
  deficiencies as it is a fat-soluble substance and
  is absorbed along with fat
• Liver disease can also prevent the liver from
  producing bile, which is required for fat and
  vitamin K absorption

91
Hemostasis Disorders Bleeding Disorders

• Hemophilias hereditary bleeding disorders
  caused by lack of clotting factors
• Hemophilia A
• Hemophilia B
• Hemophilia C

92
Blood Transfusions

• Whole blood transfusions are used
• When blood loss is substantial
• In treating thrombocytopenia
• Packed red cells (cells with plasma removed) are
  used to treat anemia

93
Human Blood Groups

• RBC membranes have glycoprotein antigens on their
  external surfaces
• These antigens are
• Unique to the individual
• Recognized as foreign if transfused into another
  individual
• Promoters of agglutination and are referred to as
  agglutinogens
• Presence or absence of these antigens is used to
  classify blood groups

94
Blood Groups

• Humans have 30 varieties of naturally occurring
  RBC antigens
• The antigens of the ABO and Rh blood groups cause
  vigorous transfusion reactions when they are
  improperly transfused

95
ABO Blood Groups

• The ABO blood groups consists of
• Two antigens (A and B) on the surface of the RBCs
  
• Two antibodies in the plasma (anti-A and anti-B)
• ABO blood groups may have various types of
  antigens and preformed antibodies
• Agglutinogens and their corresponding antibodies
  cannot be mixed without serious hemolytic
  reactions

96
ABO Blood Groups
Table 17.4
97
Rh Blood Groups

• There are eight different Rh agglutinogens, three
  of which (C, D, and E) are common
• Presence of the Rh agglutinogens on RBCs is
  indicated as Rh
• Anti-Rh antibodies are not spontaneously formed
  in Rh individuals
• However, if an Rh individual receives Rh blood,
  anti-Rh antibodies form
• A second exposure to Rh blood will result in a
  typical transfusion reaction

98
Hemolytic Disease of the Newborn

• Hemolytic disease of the newborn Rh antibodies
  of a sensitized Rh mother cross the placenta and
  attack and destroy the RBCs of an Rh baby
• Rh mother becomes sensitized when exposure to
  Rh blood causes her body to synthesize Rh
  antibodies

99
Hemolytic Disease of the Newborn

• The drug RhoGAM can prevent the Rh mother from
  becoming sensitized
• Treatment of hemolytic disease of the newborn
  involves pre-birth transfusions and exchange
  transfusions after birth

100
Transfusion Reactions

• Transfusion reactions occur when mismatched blood
  is infused
• Donors cells are attacked by the recipients
  plasma agglutinins causing
• Diminished oxygen-carrying capacity
• Clumped cells that impede blood flow
• Ruptured RBCs that release free hemoglobin into
  the bloodstream

101
Transfusion Reactions

• Circulating hemoglobin precipitates in the
  kidneys and causes renal failure

102
Blood Typing

• When serum containing anti-A or anti-B
  agglutinins is added to blood, agglutination will
  occur between the agglutinin and the
  corresponding agglutinogens
• Positive reactions indicate agglutination

103
Blood Typing
104
Diagnostic Blood Tests

• Laboratory examination of blood can assess an
  individuals state of health
• Microscopic examination
• Variations in size and shape of RBCs
  predictions of anemias
• Type and number of WBCs diagnostic of various
  diseases
• Chemical analysis can provide a comprehensive
  picture of ones general health status in
  relation to normal values