Hematology

The Hematologic System

• Definition of Hematology:

  • The study of blood.

• Functions of Blood:

  • Supplies body tissues with oxygen, nutrients, and various chemicals.

  • Transports waste products to appropriate waste systems.

  • Transports gases to and from the lungs and cells.

  • Maintains the body’s homeostasis.

  • Plays an important role in the immune system.

• Components of Blood:

  • Consists of formed elements:

  • White Blood Cells (WBCs): involved in the immune response.

  • Red Blood Cells (RBCs): carry oxygen.

  • Clotting cells (Thrombocytes): involved in the clotting process.

  • The liquid portion of blood can be defined as:

  • Serum: when the clotting factors are removed.

  • Plasma: when the clotting factors are present.

• Clotting Proteins:

  • Main proteins involved in coagulation include:

  • Fibrinogen

  • Prothrombin

  • Coagulation

  • The formation of a blood clot.

  • Anticoagulants:

  • Examples include EDTA and heparin.

Structures of Blood Cells

• Erythrocytes (RBCs):

  • Mature red blood cells that carry oxygen.

  • Erythr/o means red.

• Leukocytes (WBCs):

  • White blood cells that fight disease.

  • Two main types:

  • Granulocytes

  • Agranulocytes

  • Leuk/o means white.

• Thrombocytes (Platelets):

  • Clotting cells responsible for initiating blood clot formation.

Morphology of RBC

• Cell Size Types:

  • Normocytic: Normal cell size

  • Macrocytic: Enlarged cell size

  • Microcytic: Reduced cell size

  • Anisocytosis: Variation in cell size.

• Cell Shape:

  • Poikilocytosis: Irregular shape or size of cells.

• Color Variations:

  • Normochromic: Normal color of cell (related to hemoglobin content).

  • Polychromasia: Variation in staining characteristics of hemoglobin.

  • Hyper/Hypo refers to increased/decreased coloration.

• Cell Grouping:

  • Rouleaux: Stacking of cells.

  • Agglutination: Clumping of cells due to various causes.

Types of WBC

• Lymphocytes:

  • Responsible for producing antibodies.

• Monocytes:

  • Perform phagocytosis (engulfing pathogens).

• Neutrophils:

  • Respond to infection.

• Eosinophils:

  • Stain with acidic/pink dye, involve in response to allergens and parasites.

• Basophils:

  • Stain with basic/blue dye, release histamine during allergic reactions.

Blood Cell Terms/Conditions

• Leukocytosis: Elevated white blood cell count.

• Leukopenia: Low white blood cell count.

• Neutrophilia: Increased neutrophils.

• Neutropenia: Decreased neutrophils.

• Thrombocytopenia: Low platelet count.

• Septicemia: Presence of bacteria in the bloodstream.

• Icteric: Referring to jaundice appearance.

• Lipemia: Elevated fat (lipid) levels in the blood.

The Lymphatic System

• Functions of the Lymphatic System:

  • The body's immune response.

  • Responsible for filtering waste.

  • Maintaining fluid balance in the body.

  • Fighting infections.

Structures of the Lymphatic System

• Lymph fluid:

  • Also called interstitial fluid.

• Lymph vessels:

  • Carry lymph fluid throughout the body.

• Lymph nodes:

  • Filter lymph and remove bacteria and viruses.

  • Enlarged nodes can occur due to disease processes.

• Lacteals:

  • Specialized lymphatic vessels located in the small intestine.

Specific Structures of the Lymphatic System

• Nodes Include:

  • Submandibular Nodes

  • Cervical Nodes

  • Axillary Node

  • Inguinal Node

  • Popliteal Node

  • Thoracic Duct

• Morphological Structure:

  • Cross Section: Showing lymph nodes and ducts.

• Tonsils:

  • Masses of lymphatic tissue that protect the nose and upper throat.

  • The combining form is Tonsill/o.

• Spleen:

  • Mass of lymphatic tissue in the cranial abdomen that filters blood.

• Thymus:

  • Gland in the cranioventral thoracic cavity where T lymphocytes mature.

The Immune System

• Definition of the Immune System:

  • Functions to protect the body from harmful substances.

  • Immun/o means protected.

• Specialized Cells:

  • T Lymphocytes: Responsible for antigen recognition.

  • B Lymphocytes: Responsible for antibody-mediated immunity.

• Production of Immunoglobulins:

  • Ig Types:

  • IgA, IgD, IgE, IgG, IgM.

Mechanism of the Immune System

• Activation:

  • The immune system is activated when the first line of defenses fail.

• Specificity:

  • The immune response is directed against a specific antigen.

• Memory Function:

  • Allows the immune system to recognize previously encountered antigens and respond quickly.

Types of Immunity

• Naturally Acquired Passive Immunity:

  • Transfers antibodies from mother to offspring.

• Naturally Acquired Active Immunity:

  • Developed from having the disease.

• Artificially Acquired Passive Immunity:

  • Introduction of serum with antibodies from a donor.

• Artificially Acquired Active Immunity:

  • Lifelong immunity gained through vaccination.

Oncology

• Definition of Oncology:

  • The study, diagnosis, and treatment of tumors.

  • Onc/o means tumor.

• Types of Tumors:

  • Malignant: Cancerous tumors.

  • Benign: Nonmalignant tumors.

• Neoplasm:

  • Any abnormal new growth of tissue in which cell multiplication is uncontrolled and progressive.

• Metastasis:

  • Pathogenic growth that occurs distant from the primary disease site, referentially called “beyond control.”

Types of Neoplasm

• Carcinoma:

  • Malignant growth of epithelial cells.

• Sarcoma:

  • Malignant growth of connective tissue.

• Additional Types Include:

  • Adenocarcinoma

  • Blastoma

  • Hemangioma

  • Lymphoma

  • Mast cell tumor

  • Melanoma

  • Myosarcoma

  • Osteosarcoma

  • Squamous cell carcinoma.

Oncology Diagnostics

• Diagnostic Procedures Include:

  • Biopsy:

  • Various methods including needle (fine needle aspiration), incisional, excisional, punch, brush/exfoliative, and impression/touch preps.

  • Cytology and Histopathology:

  • Examination of the cellular structure and tissue pathology to diagnose tumors.

Medical Terms for Blood, Immunity, and Oncology

• Additional terms relating to blood, immunity, and tumor tests, along with pathology and procedures, can be found in the accompanying text.