CHAPTER 30: Introduction to the Hematopoietic and Lymphatic Systems

STUDENT LEARNING OUTCOMES

• Define hematopoiesis: The process of manufacturing and development of blood cells.

• Name the major structures in the hematopoiesis system:

  • Bone marrow

  • Blood

  • Lymphatic system

• Name the three types of blood cells produced by bone marrow and discuss the function of each:

  • Erythrocytes (RBCs): Transport oxygen and remove carbon dioxide from tissues.

  • Leukocytes (WBCs): Promote immune response.

  • Platelets (Thrombocytes): Major component of clotting.

• List at least five components of plasma:

  • Water

  • Proteins

  • Nutrients

  • Electrolytes

  • Waste products

• Name three plasma proteins and explain the function of each:

  • Albumin: Maintains osmotic pressure.

  • Globulins: Prevent and modify infections.

  • Fibrinogen: Forms blood clots.

• Identify the four blood groups and discuss the importance of transfusing compatible types:

  • Groups: A, B, AB, and O;

  • Importance: Compatibility of antigens and Rh factor is crucial for safe transfusions.

• Explain components and function of the lymphatic system and its role in hematopoiesis:

  • Components: Thymus gland, spleen, lymph nodes.

  • Function: Filters pathogens, assists in lymphocyte maturation.

• Describe pertinent assessments of the hematopoietic and lymphatic systems when obtaining health history and conducting physical examination:

  • Health history includes: prolonged bleeding, fatigue, infections, dietary history, drug history, foreign travel.

• Name laboratory and diagnostic tests for disorders of the hematopoietic and lymphatic systems:

  • Blood tests such as CBC, prothrombin time, and lymph node biopsy.

• Discuss the nursing management of clients with hematopoietic or lymphatic disorders:

  • Assess knowledge of procedures, ensure safety in specimen collection, monitor vital signs, and report test results.

HEMATOPOIETIC SYSTEM

Hematopoiesis

• Definition: Manufacturing and development of blood cells.

Structures in the Hematopoietic System

• Bone marrow: Soft tissue filling spaces in the interior of long and spongy bones. Produces pluripotent stem cells, which generate all blood cell types.

• Blood: Consists of cells (derived from pluripotent stem cells) suspended in plasma.

• Lymphatic system: Circulates interstitial fluid and supports hematopoiesis.

BLOOD

Blood Components

• Types of Blood Cells:

  • Erythrocytes (RBCs): Transport O₂ and remove CO₂ from tissues.

  • Leukocytes (WBCs): Primary immune response units.

  • Platelets (Thrombocytes): Clotting components.

Erythrocytes (RBCs)

• Role: Transport oxygen and remove carbon dioxide.

• Erythropoiesis: Production of erythrocytes regulated by erythropoietin (a hormone released by the kidneys).

• Nutritional Requirements: Requires iron, vitamin B₁₂, vitamin B₆, and folate.

• Erythroblasts: Immature erythrocytes.

• Hemoglobin: A protein in RBC that carries oxygen (Adult level: 12.0 to 17.4 g/dL).

• Bilirubin: Waste product from the liver from the breakdown of erythrocytes.

Leukocytes (WBCs)

• Function: Promote immune response through phagocytosis and antibody production.

• Normal level: 5000 to 10,000 mm³.

• Leukocytosis: Increased leukocyte count.

• Leukopenia: Decreased leukocyte count.

• Life span: 1 to 2 days, continuous demand particularly during infection.

Types of WBCs/Leukocytes

• Granulocytes:

  • Neutrophils/Microphages: Primary component in inflammatory responses.

  • Basophils: Active in allergic reactions.

  • Eosinophils: Active in allergic, dermatologic, and parasitic infections.

• Agranulocytes:

  • Lymphocytes: Include B lymphocytes and T lymphocytes.

Granulocyte Percentages

• Total WBC percentages:

  • Neutrophils: 60-70% (3000-7000 mm³)

  • Basophils: 0.5-1% (25-100 mm³)

  • Eosinophils: 2-6% (50-400 mm³)

  • Lymphocytes: 20-40% (1000-4000 mm³)

  • Monocytes: 1-4% (100-600 mm³)

Platelets (Thrombocytes)

• Major role: Clotting mechanism.

• Life span: Approximately 7.5 days.

• Mechanism: Migrate to injury site, release glycoprotein IIb/IIIa causing aggregation and clot formation.

Plasma

Plasma Contents

• Composition: 90% water, 10% proteins, <1% other components.

• Major Plasma Proteins:

  • Albumin: Maintains osmotic pressure.

  • Globulins: Function in immune response.

  • Fibrinogen: Essential for blood clot formation.

BLOOD TYPING

Blood Groups

• Four types: A, B, AB, and O.

• Antigens: Identifying proteins on blood cells; can be present or absent.

• Rh factor: Identifying protein that can be positive or negative; essential for compatibility in transfusions.

Compatibility in Blood Transfusions

• Type O is a universal donor.

• Type AB+ is a universal recipient.

• Blood transfusions must match both antigen type and Rh factor.

Compatibility Table

Complete Blood Count (CBC) Parameters

• 
  
  

• CBC Normal Values:
  
  

  
  

  Component	Adult Men	Adult Women
  Red Blood Cells (million/mm³)	4.6-6.2	4.2-5.4
  Hematocrit (%)	40-54	38-47
  Hemoglobin (g/dL)	13.5-18	12-16
  Mean Cell Volume (MCV)	80-94	81-99
  Mean Cell Hemoglobin (MCH)	27-31	27-31
  Mean Cell Hemoglobin Concentration (MCHC) (g/dL)	32-36	32-36
  Reticulocytes (% of RBCs)	0.5%-2.0%	Slightly higher in females
  White Blood Cells (per mm³)	5000-13,000
  Platelets (per mm³)	150,000-450,000
  Functions of Blood Components

  Summary of Blood Functions

  Component	Function
  Erythrocytes	Transport oxygen and carbon dioxide
  Leukocytes	Protect against infection
  Platelets	Participate in blood clotting
  Plasma	Circulate blood cells and noncellular components
  Albumin	Maintain osmotic pressure
  Fibrinogen	Convert a loose blood clot to a stabilized blood clot
  Globulin	Type of plasma protein involved in immune responses
  Water	Contributes to blood volume and pressure
  Nutrients	Provide energy and essential functions
  Electrolytes	Involved in various physiological processes

  LYMPHATIC SYSTEM

  Overview

  • Definition: A pathway that filters, destroys, and/or removes pathogens and other harmful substances; circulates interstitial fluid and carries it to the veins; assists with maturation of lymphocytes (a type of white blood cell).

  • Components:

    • Thymus gland

    • Spleen

    • Lymph nodes

    • Lymph fluid

  Thymus Gland

  • Function: Produces lymphocytes during fetal development; programs T lymphocytes post-birth; shrinks during adolescence.

  Spleen

  • Functions: Serves dual roles in hematopoiesis and immune responses; acts as an emergency blood reservoir; removes old or damaged RBCs and bacteria from circulation.

  Lymph Nodes

  • Function: Drain tissue fluid (lymph); consist of an interconnected network:

    • Superficial lymph nodes located in: axilla, groin, and neck; provide filtration through macrophages that attack and engulf foreign particles.

  Lymph Fluid

  • Function: Carries lymphocytes and is filtered through nodes, where macrophages play a critical role.

  CELL PRODUCTION IN HEMATOPOIESIS

  Stem Cells and Progenitor Cells

  • Hematopoietic Stem Cell: The beginning point for producing all blood cells; divides into:

    • Myeloid progenitor cell:

    • Produces erythrocytes, monocytes, neutrophils, eosinophils, basophils, and platelets.

    • Lymphoid progenitor cell:

    • Produces T cells, B cells, and natural killer (NK) cells.

  ASSESSMENTS & NURSING PROCESSES

  Health History Considerations

  • Key questions include:

    • Prolonged bleeding from injury

    • Unexplained blood loss

    • Fatigue or faintness with normal activities

    • Sensitivity to cold and frequent infections

  • Dietary history: Important information as compromised nutrition can affect RBC and hemoglobin production.

  • Drug history: Review prescription and non-prescription medications, particularly anticoagulants and antibiotics.

  • Travel history: Areas where malaria or parasitic infections are common, as these can lead to anemia or other complications.

  Physical Examination

  • Skin assessment: Look for color, temperature, and lesions.

  • Pulse assessment: Monitor for tachycardia which may indicate inadequate hemoglobin levels.

  • Lymph node palpation: Check for tenderness or swelling.

  • Tonsil examination: Assess size and appearance, using a scale from 1 to 4.

    • Scale:

    • 1 = Tonsils visible.

    • 2 = Extensions toward the uvula.

    • 3 = Touching the uvula.

    • 4 = Touching each other.

  Diagnostic Tests

  • Common tests include:

    • Complete Blood Count (CBC)

    • Prothrombin times

    • Fibrinogen levels

    • Bone marrow aspiration

    • Lymph node biopsy

    • Spleen ultrasound

    • Lymphangiography

    • CT scans, bone scans, MRI.

  Nursing Management

  • Assess the client’s understanding of necessary procedures; provide descriptions of tests and routines.

  • Follow safety precautions when collecting specimens:

    • Standard precautions such as gloves; sterile techniques are necessary for specific procedures like bone marrow biopsies.

  • Monitor vital signs and communicate adverse reactions to the primary provider.

  • Analyze and report all diagnostic test results promptly.

  GOOD LUCK ON THE TEST!

  • Wishing success in your assessments!

  PRACTICE QUESTIONS

  1. Which medication should be contraindicated in a patient with thrombocytopenia?
     A) Filgrastim (Neupogen)
     B) Warfarin (Coumadin)
     C) Epoetin alfa (Epogen)
     D) Pegfilgrastim (Neulasta)

  2. What is the lifespan of a white blood cell?
     A) 1-2 hours
     B) 1-2 days
     C) 50-60 hours
     D) 50-60 days

  3. Which of the following statements are true? (Select all that apply.)
     A) The 3 blood components are platelets, white blood cells, and red blood cells.
     B) White marrow contains fatty & connective tissues.
     C) Only red blood cells are made from pluripotent stem cells.
     D) Blood is suspended in plasma.

  4. If you have A- blood, what transfusions can you receive?
     A) A-, A+, AB-, AB+
     B) A+, A-
     C) A-, O-
     D) A-, A+, O-