Hematopoietic System

Blood

Only connective tissue

Plasma Content

• Water

• Proteins (Albumin)

• Electrolytes

• Dissolved Gases

Buffy Coat Content

• Platelets

• Leukocytes

Fibrinogen

Found in plasma, plays a key role in clotting process

RBC

• Transports gases

• Biconcave shape

• No nucleus

WBC

• Defends body from infections and foreign invaders

• Has nucleus

• Larger than RBC

Platelets

• Forms plug at vascular injury site

• Fragments of megakaryocytes

• No nucleus, granulated

Normal RBC Values

• Male: 5.4 million per microliter

• Female: 4.8 million per microliter

Mean Corpuscular Hemoglobin Concentration (MCHC)

• Measures amount of Hgb per volume of RBC

• 32 - 36 g / dL

• Hypochromic: Low

• Hyperchromic: High

Erythropoiesis

RBC production and maturation

HgB

• Transport gases

• Maintains blood pH

Methemoglobin

Oxidized HgB

Reticulocyte Count

• Measures percentage of reticulocytes in the blood

• Determines rate of erythropoiesis

• 0.5% - 1.5% of total blood cells

• Reticulocytopenia: Low

• Reticulocytotic: High

Hematocrit

• Measures the percentage of RBC in the blood

• Male: 38.3% - 48.6%

• Female: 35.5% - 44.9%

• Anemia: Low

• Polycythemia: High (65%)

Mean Corpuscular Volume (MCV)

• Measures average RBC size

• 80 - 100 femtoliters (fl)

• Microcytotic: Low

• Macrocytotic: High

Mean Cell Hemoglobin (MCH)

• Measures average amount of Hgb per RBC

• 27 - 31 picograms / cell

Red Blood Cell Distribution Width (RDW)

• Measures size variation of RBC

• 10.5% - 15%

• Anisocytosis: High

Poikilocytosis

Abnormal variation in shapes of the red cell population

Acanthocytes

Thorn-like shape of RBC

Codocytes

Darkly stained RBC central area

Dacrocytes

Pearl or tear drop-shaped RBC

Drepanocytes

Sickle cells RBC

Echinocytes

Short thorn-like projections from RBC

Elliptocytes

Elliptical RBC

Erythrocyte Sedimentation Rate

• Measures the rate at which red blood cells settle at the bottom of a vertical tube of blood over a certain period

• Screen test for inflammatory, autoimmune, or cancer

• Male: <20mm / hour

• Female: <30mm / hour

Pregnancy Test

• Tests for human chronic gonadotropin in blood (hCG)

• Very sensitive

Iron-deficiency Anemia

• Caused by an inadequate absorption or excessive loss of iron

• Most avoidable anemia

• Microcytic, Hypochromic

Pernicious Anemia

• Caused by the inability of the stomach to produce intrinsic factor

• Intrinsic factor:

  • need for Vit. B12 absorption to make RBC

• Macrocytotic, Megaloblastic

Hemorrhagic Anemia

• Excessive loss of RBCs through bleeding

• Acute:

  • Extraordinarily heavy bleeding

  • Large wounds, Heave menstrual cycle

• Chronic:

  • Slow, prolonged bleeding

  • Stomach ulcers

Hemolytic Anemia

• Premature rupture of RBCs 

• Distortion in the shape of erythrocytes

• Causes:

  • Inherent defects

  • Toxins / Parasites

  • Abs from incompatible blood

Hemolytic Disease of the Newborn (Erythroblastosis fetalis)

• RBCs of the fetus are being targeted and lysed by the mother’s antibodies

• HDN due to Rh incompatibility between mother and child

Hydrops Fetalis

• Abnormal fluid accumulation in two or more fetal compartments, leading to significant swelling or edema

• All 4 genes for alpha synthesis chains are defective

Thalassemia

• Genetic blood disorders characterized by abnormal hemoglobin production, resulting in the reduced or absent synthesis of one or more of its components,  leading to anemia

• Microcytotic, Hypochromic, Short-lived

• Need blood transfusions

Beta Thalassemia

Synthesis of the beta chains genes  are defective or missing

Beta Thalassemia Minor

One gene for beta chain synthesis is missing

Beta Thalassemia Major

Both genes for beta chain synthesis are missing

Alpha Thalassemia

Synthesis of alpha chains genes are defective or missing

Secret Carrier

One alpha chain gene missing

Alpha Thalassemia Minor

Two alpha chain gene missing

Hb H Disease

Three alpha chain gene missing

Aplastic Anemia

Decrease or failure in the production of all types of blood cells in the bone marrow

Pancytopenia

• Significant reduction in the number of all three major types of blood cells

• Not a disease, but a manifestation of an underlying condition affecting the bone marrow

• Causes:

  • Toxins

  • Radiation / Chemotherapy

• Need bone marrow transplant with immunosuppression

Sickle Cell Anemia

• Abnormal Hgb (Hgb-S) present in the RBCs

• Sickle RBC rupture easily and can obstruct blood vessels

• Symptoms:

  • Hand-foot syndrome for children

  • Limb and back pain for elderly

Hemolytic Anemia

Low oxygen supply to the tissues which results in tissue damage

Normal Hgb Types

• HbA/HbA1

  • 95% - 98% for healthy adults

• HbA2

  • 2% - 3% for healthy adults

• HbF

  • 50% - 80% for newborns

  • Declines over lifetime

HbS

• Abnormal Hgb

• Mutation in beta globin chain

HbAS

• Mutation in one beta globin chain

• Asymptomatic

HbSS

Mutation in both beta globin chains

Polycythemia

• Abnormally high RBC count

• Results:

  • Increased blood viscosity

  • Increased BP

  • Thrombosis

Leukemia

• Abnormal increase in WBC count

• Acute:

  • Uncontrolled production and accumulation of immature leukocytes

• Chronic:

  • Accumulation of mature leukocytes

Infectious Mononucleosis (IM)

• Contagious disease that affects the lymphatic tissue and blood

• Most common in female children and young adults

Epstein-Barr Virus (EBV)

• ”Kissing virus”

• Multiplies in the lymphatic tissues, spreads into the blood and infects B lymphocytes

• B lymphocytes become enlarged and begin to look like monocytes

Vascular Spasm

Smooth muscle contracts immediately when arteries or arterioles are damaged

Platelet Plug Formation

• Large numbers of platelets accumulate and attach to form a mass

• Platelet release reaction:

  • TXA2

  • 5-HT

  • ADP

Coagulation / Blood Clotting

Blood clot mechanism that prevents excessive bleeding when a blood vessel is

injured

Hemophilia A

Excess / deficient in CF VIII (Von Willebrand factor / AHFA / AHG)

Hemophilia B

Excess / deficient in CF IX (Christmas factor / PTC / AHFB)

Hemophilia C

Excess / deficient in CF XI (PTA / AHFC)

Vitamin K Deficiency

Deficiencies in some/all CF II, VII, IX, X

Intrinsic Clotting

• Activated by trauma in blood

• Involves CF VII, VIII, IX, XI

• Slower than extrinsic clotting

Extrinsic Clotting

• Activated by vascular tissue trauma

• Involves CF III

• Quicker than intrinsic clotting

CF I

Fibrinogen

CF II

Prothrombin

CF III

Tissue factor / Thromboplastin

CF IV

Calcium ions

CF V

• Proaccelerin

• Labile factor

• Accelerator globulin (AcG)

CF VII

• Serum prothrombin conversion accelerator (SPCA)

• Stable factor

• Proconvertin

CF VIII

• Von Willebrand factor

• Antihemophilic factor A (AHFA)

• Antihemophilic globulin (AHG)

CF IX

• Christmas factor

• Plasma thromboplastin component (PTC)

• Antihemophilic factor B (AHFB)

CF X

• Stuart factor

• Prower factor

• Thrombokinase

CF XI

• Plasma thromboplastin antecedent (PTA)

• Antihemophilic factor C (AHFC)

CF XII

• Hagerman factor

• Glass factor

• Contact factor

• Antihemophilic factor D (AHFD)

CF XIII

Fibrin-stabilizing factors (FSF)

Vitamin K

• Necessary to achieve normal clotting

• Used to produce CF:

  • II

  • VII

  • IX

  • X

Fibrinolysis

• Process in which blood clots are dissolved or broken down after they have served their purpose

• Plasminogen turns into plasmin

• Plasmin dissolves clot by digesting CF I, II, V, VIII, XII

Prostacyclin / Prostaglandin 12

 Inhibitor of platelet adhesion and release

Antithrombin III (AT-III)

Blocks action of factors II, IX, X, XI, and XII

Protein C

Inactivates factors V and VIII; enhances activity of plasminogen activators

Alpha-2-macroglobulin

Inactivates thrombin and plasmin

Alpha-1-antitrypsin

Inhibits factor XI

Heparin

Combines with AT-III, increasing its effectiveness in blocking thrombin

Thrombocytosis

Abnormal increase in the platelet count

Thrombocytopenia

Abnormal decrease in the platelet count

Hemophilia

• Deficiency is a sex-linked, inherited disorder

• Defective gene is carried on the X chromosome

• Symptoms:

  • Bruises

  • Deep muscle bleeding

  • Joint bleeding

Intravascular Clots

Roughened endothelial surfaces of BVs because of atherosclerosis, trauma, or infection induce platelet adhesion

Thrombus

Stationary clot that forms in a blood vessel

Emboli

• Dislodged and transported thrombus to other parts of the body

• Air bubbles, fat, debris from broken bones, tumor cells

Von Willebrand’s Disease

• Deficient in CF VIII

• Inherited bleeding disorder

Multiple Myeloma

• Cancerous disorder of plasma cells

• Plasma cells often form tumors in bones or soft tissues of the body