Blood and Blood Typing

Lab 4: Blood and Blood Typing

Lab 4 Outcomes

  • Identify and describe the histology of blood connective tissue.
  • Describe the ABO blood typing system.
  • Explain the antigens and antibodies of each blood type.
  • Identify blood types and interpret results of a blood typing procedure.
  • Match donors and recipients of blood types during a blood transfusion.
  • Describe how blood testing is used for clinical diagnosis.
  • Define and spell key terms (terms in tables and bold terms in the text).

Key Terms

  • plasma
  • leukocyte
  • hemolysis
  • antigen
  • A antigen
  • anti-A antibody
  • A- / A+
  • B- / B+
  • Blood Connective Tissue
  • formed elements
  • erythrocyte
  • thrombocyte (platelet)
  • hemoglobin
  • ABO Blood Typing System
  • antibody
  • B antigen
  • anti-B antibody
  • Blood Types
  • AB- / AB+
  • agglutination
  • Rh antigen
  • anti-Rh antibody
  • Transfusions, Donations, and Pathophysiology
  • universal donor
  • universal recipient
  • crossmatch
  • buffy coat
  • hematocrit (packed cell volume)
  • white blood cell differential
  • lipid/cholesterol panel
  • 0-10+
  • blood transfusion
  • complete blood count
  • blood chemistry
  • hemolytic disease of a newborn (erythroblastosis fetalis)

Key Information - Blood Connective Tissue

  • Blood connective tissue is a type of connective tissue with a liquid matrix.
  • Constituents:
    • Plasma: Mostly water, protein, electrolytes, hormones, and other water-soluble substances are dissolved in plasma.
    • Formed Elements: Comprised of three main types created in the red bone marrow:
    • Erythrocytes
    • Leukocytes
    • Thrombocytes (platelets).

Characteristics of Blood Components

  • Erythrocytes (Red Blood Cells):

    • Biconcave shape for flexibility and increased surface area for oxygen diffusion.
    • Contains hemoglobin, an iron-containing protein that binds oxygen and carbon dioxide.
    • Color: Reddish due to the iron-containing heme group in hemoglobin.
    • Lacks organelles, including the nucleus, enabling more hemoglobin storage.

  • Leukocytes (White Blood Cells):

    • Integral to the immune system.
    • Five types: Basophils, Eosinophils, Neutrophils, Monocytes, and Lymphocytes.
    • Fewer in number than erythrocytes, but contain organelles and large nuclei that stain well.

  • Thrombocytes (Platelets):

    • Cell fragments that play a crucial role in hemostasis (blood clotting).

ABO Blood Typing System

  • Antigens: Large proteins on cell surfaces that trigger immune responses.
  • Cells possess surface antigens that the immune system recognizes as "self". Non-self antigens activate antibodies.
  • Immune Response: Binding of antibodies to antigens can result in agglutination (clumping of cells).
  • Agglutination enhances phagocytosis efficiency by leukocytes.
Blood Types in ABO System
  • Blood types are determined by the presence of A, B, and Rh antigens:
    • Type A: Presence of A antigen.
    • Type B: Presence of B antigen.
    • Type AB: Presence of both A and B antigens.
    • Type O: Neither A nor B antigen.
  • Each blood type can be positive (+) or negative (-) based on the presence of the Rh antigen.
Antibodies Produced
  • Following exposure to antigens, the immune system produces antibodies against non-self antigens:
    • No A antigen → produce anti-A antibody
    • No B antigen → produce anti-B antibody
    • Rh- exposure → produce anti-Rh antibody
  • Agglutination can cause severe reactions leading to hemolysis (rupture of erythrocytes).

Blood Typing Test Procedure

  • Blood samples are mixed with serums containing specific antibodies:

    • Anti-A Serum: Tests for the A antigen.
    • Anti-B Serum: Tests for the B antigen.
    • Anti-Rh Serum: Tests for the Rh antigen.

  • Agglutination Result: Indicates a match between the serum antibody and erythrocyte antigen.

  • No change means the sample is negative for that specific antigen.

Blood Transfusions

  • Involves transferring blood from one individual to another.
  • To minimize transfusion reactions, donor erythrocytes and recipient plasma must be compatible:
    • Crossmatch: Mixing blood samples to confirm compatibility before transfusions.
  • Transfusion Reaction: When erythrocytes clump, leading to disrupted blood flow; symptoms include nausea, hives, vomiting, and potential loss of consciousness.
Universal Donor and Recipient
  • Universal Donor: O- blood type, as they contain no antigens for recipient reactions.
  • Universal Recipient: AB+ blood type, as they possess all three antigens and no antibodies against other blood types.

Blood Testing for Clinical Diagnosis

  • Blood samples can diagnose various organ disorders.

  • Centrifugation separates blood components by density:

    • Plasma: Top layer, contains transported substances.
    • Buffy coat: Middle layer, contains leukocytes and platelets.
    • Formed elements: Bottom layer, primarily erythrocytes.

  • Hematocrit: Estimates percentage of blood volume occupied by erythrocytes, typically 35-55% in healthy individuals.

  • Complete Blood Count (CBC): Evaluates numbers and morphology of erythrocytes, leukocytes, and thrombocytes.

  • Blood Chemistry Panel: Assesses organ function and nutrient/electrolyte concentrations; includes cholesterol levels for cardiovascular disease risk.

Pathophysiology in Pregnancy

  • The placenta serves as a nutritional barrier that may pose risks if the fetus has a different blood type than the pregnant person.

  • Anti-Rh Antibody risks are present if the mother is Rh- and has had previous exposure to Rh+ blood, leading to potential hemolytic disease of the newborn (HDN).

  • In cases of Rh incompatibility, preventative measures like RhoGAM injection are used to neutralize Rh antigens and prevent sensitization.

  • Symptoms of HDN include jaundice, pale skin, and edema due to erythrocyte destruction by maternal antibodies.