Hemotology

Hematology

Hematology

• The study of blood and blood forming organs

Hematopoiesis

• The process through which pluripotent stem cells differentiate into various types of blood cells.

• Before birth, this happens in spleen, liver, lymph nodes, and thymus

• After birth, happens in bone marrow

Blood Volume

• 6% of total body weight• Body can compensate for .5 liters blood loss• Fluid shift can easily alter amount of blood• Number of red blood cells remain constant• Red blood cells confined to vascular space

Blood Components

• Plasma• Red blood cells• White blood cells • Platelets

Plasma

• 90-92 % water• 6-7% proteins• Large proteins (Albumin) won’t cross

membranes• Osmotic Pull (Oncotic pressure)- water

retention

Erythropoietin

• Hormone responsible for red blood cell production

Red Blood Cells

• Erythrocyte- red blood cell• No nucleus when mature

Hemoglobin

• Oxygen-bearing molecule in RBC• Made up of iron-rich pigment- heme and

protein- globin• Each hemoglobin has 4 subunits of globin• Each globin can carry one Oxygen molecule

Oxygen Transport

• Normal pO2 is 95 mmHg• Bohr effect- Uptake of O2 in lungs:• Alkalosis makes hemoglobin bind to oxygen

more tightly• Acidosis makes hemoglobin release oxygen

Erythropoeisis

• Production of red blood cells

Hemolysis

• Destruction of red blood cells

Lab Values H&H

• Hematocrit - Packed red cell volume• Normal 40 -52%• Hemoglobin• Normal 12 – 15 g/dL for males• Normal 10.5-14.0 g/dL for females

White Blood Cell Production

• Leukopoiesis (differentiation of WBC)• Immature WBC:– Myeloblasts– Monoblasts– Lymphoblasts

White Blood Cells

• Granulocytes• Monocytes• Lymphocytes

Granulocytes

• Basophils- primary function in allergic reaction… contain histamine….

• Eosinophils-Fight parasitic infection… can counteract allergic reactions

• Neutrophils- count can rise rapidly… fight infection

Monocytes

• May circulate as monocytes or mature into “Macrophages”

• Garbage collectors

Lymphocytes

• Primary cells involved in immune response• T- Cells (thymus)• B- Cells (bone marrow)

Autoimmune Disease

• Condition in which the body makes antibodies against own tissues

Inflammatory Response

• Nonspecific defense mechanism that wards off damage from microorganisms or trauma

White Blood Cells

• Leukocytes• Many (marginalized) loiter on walls of blood

vessels.• Demargination- recirculation of WBC in

response to stress, corticosteroids, seizures, epinephrine, and exercise

Phagocytosis

• When white blood cells engulf and destroy an invader

Platelets

• Throbocytes• 150,000 – 450,000 per microliter of blood• Live 7 – 10 days• Removed by the spleen• Thrombocytosis – too many

Hemostasis

• Vascular Spasms• Platelet Plug• Stable Fibrin Blood Clots

Blood Clot Destruction

• Plasminogen- released from fibrin clot• Turned into plasmin… • Fibrinolyis- plasmin dismantles blood clot• Takes hour to days

Blood Types

• A• B• AB• O

Rh Factor

Blood Compatibility

• AB- universal recipient• 0- universal donors• Type A- A-antigens, anti-B antibodies

Types of Transfusions

• Whole blood• Packed red blood cells• Platelets• Fresh frozen plasma• Clotting factors

Transfusion Reactions

• Facial flushing, hyperventilation, tachycardia, sense of dread

• Hives, chest pain, wheezing, fever, chills, cyanosis

Patient Assessment

• Petechiae (tiny red dots in skin)• Purpura (large purplish blothces)- high

bilirubin• Epistaxis• Enlarges spleen• Bleeding from gums• Arthralgia-pain and swelling in joints• Bleeding around IV site

Diseases of RBC

• Polycythemia- too many• Anemia- inadequate number of RBC or

inadequate hemoglobin

Anemia

• Symptom, not a disease• Hematocrit < 37 % in women < 40% in men• Pica- craving of unusual substances as ice or

clay

Sickle Cell Disease

• Inherited disorder of RBC production• Mom Xx Dad Xx• Babies XX Xx Xx xx• Xx – carriers of sickle cell trait• xx have disease

Polycytemia

• Hematocrit too high• > 50%• Rare disorder• 50 y/o +

WBC Diseases

• Leukopenia – too few (treatment is supportive)- prevent infection

• Leukocytosis – too many– Look for neutrophils with segmented nuclei

(bands)

Leukemia

• ALL, AML, CLL, CML, Hairy cell leukemia• High risk of infection

Lymphoma

• Cancers of the lymphatic system– Hodgkin’s lymphoma (better survival rate)– Nonhodgkin’s lymphoma

Platelet Diseases

• Thrombocytosis - Increase in number of platelets

• Thrombocytopenia- abnormal decrease in number of platelets

Hemophelia

• Disease in which one of the proteins necessary for blood clotting is missing or defective

• Hemophelia A- Deficiency in factor VIII (most common)

• Hemophelia B (Christmas Disease)- Deficiency if factor IX rarer and more severe

Hemophelia

• Sex- Linked• Normal Dad + Carrier Mom• XY + Xx• Children XX Xx (carrier) XY xY (hemophelia)

Von Willebrand’s Disease

• vWF component of factor VIII is deficient

Multiple Myeloma

• Cancerous disorder of plasma cells• Pain in ribs or back• Pathological fractures

DIC

• Disseminated Intravascular Coagulation• Caused by systemic activation of the

coagulation cascade• Widespread thrombosis• Bleeding due to decreased fibrinogen level,

consumption of coagulation factors, thrombocytopenia