Blood and Its Functions Quiz

Blood Physiology

• Blood is a specialized bodily fluid that circulates in arteries and veins.
• It's a fluid connective tissue.
• Blood comprises around 55% plasma and 45% formed elements.
• Plasma transports blood cells, proteins, electrolytes, hormones, and nutrients throughout the body.
• Plasma brings waste products from tissues to the urinary system.
• Blood has three main types of blood cells with significant functions.
• Red blood cells (erythrocytes) carry oxygen from lungs to body.
• White blood cells (leukocytes) protect against pathogens (disease-causing organisms).
• Platelets (thrombocytes) clump together to repair broken blood vessels.

Blood Composition

• Blood is composed of:
  • Plasma (55%): Liquid component, primarily water.
  • Formed Elements (45%):
    • Red blood cells (erythrocytes)
    • White blood cells (leukocytes)
      • Granulocytes (neutrophils, eosinophils, basophils)
      • Agranulocytes (monocytes, lymphocytes)
    • Platelets (thrombocytes)
• Hemoglobin is the principal determinant of blood color

Blood Cell Development

• Blood cells produced in bone marrow.
• Two types of marrow: Red (active) and yellow (inactive).
• Stem cells differentiate into various blood cells.

Hematopoiesis

• The process of blood cell formation.
• Multipotential hematopoietic stem cells (hemocytoblasts) are the precursors to all blood cells.
• Common myeloid and lymphoid progenitors.
• Erythropoiesis, the formation of red blood cells
• Leukopoiesis, the formation of white blood cells

Red Blood Cells (RBCs)

• Erythrocytes are anucleated.
• Their main function is oxygen transport.
• Hemoglobin is a respiratory pigment.
• Hemoglobin carries oxygen and carbon dioxide.
• In humans, erythropoiesis mostly happens in bone marrow.
• In early fetal development, it happens in the yolk sac and later in the liver.
• Hemoglobin is comprised of iron, giving blood its red color.

Erythropoietin

• A glycoprotein hormone.
• Controls erythropoiesis (red blood cell production).
• Primarily produced in kidneys.

Blood Groups

• ABO system: Four main blood types (A, B, AB, O).
• Rh system: Positive (Rh+) or Negative (Rh-).
• Blood transfusions should consider blood type compatibility to avoid clotting or hemolysis.
• There are two main types of antigens.

Blood Group System

• Blood types A, B, AB and O
• Antigen A on surface of red blood cells
• Antigen B on surface of red blood cells
• Antibodies for the opposing blood groups
• The presence or absence of hereditary antigen substances on red blood cells.
• Plasma contains antibodies to antigens that are not present.

Rh Blood Group System

• Important for blood transfusions.
• Rh factor (antigen D) presence determines positive or negative type.
• Compatibility critical to avoid problems during transfusions

Blood Transfusion

• Precautions to avoid reactions.
• Compatibility testing is crucial (ABO, Rh testing).
• Blood must be fresh and stored properly.

White Blood Cells (WBCs)

• Leukocytes.
• Protect against infections.
• Types: Granulocytes (neutrophils, eosinophils, basophils) and Agranulocytes (lymphocytes, monocytes).
• Different types have different roles in the infection response and immune system.

Immunity

• Ability of the body to resist or fight off organisms that cause disease, such as bacteria, viruses or parasites
• Innate immunity: Born with this
• Adaptive immunity: Develops over time after exposure to germs
• Passive immunity: Temporary borrowed immunity from another source

Immune Abnormalities

• Immune deficiency (failure of the immune system to work properly).
• Hypersensitivity (allergies or autoimmune diseases).
• Autoimmune diseases are when your body's immune system attacks healthy cells and tissues.
• Such as asthma, urticaria and AIDS

Platelets and Blood Coagulation

• Platelets (thrombocytes) are essential for blood clotting.
• Blood coagulation: The process of forming clots in damaged blood vessels to stop bleeding.
• Hemostasis: The entire process of stopping bleeding (vascular constriction, platelet plug, blood clot formation and clot dissolution).
• Factors involved in blood coagulation: Various proteins and factors.

Anticoagulants

• Chemicals that prevent blood clots.
• Physiological & therapeutic types, such as Vitamin K antagonists, direct oral anticoagulants (DOACs), and low-molecular-weight heparins (LMWHs).
• Maintaining blood flow is crucial to prevent blockage

Blood Disorders

• Anemia: Low red blood cell count or reduced hemoglobin
• Polycythemia: High red blood cell count

Disorders of Haemostasis

• Hypercoagulable disorders are where blood clots too easily.
• Hypocoagulable disorders are where blood clots too slowly.
• Bleeding disorders are where an individual cannot form blood clots effectively.

Inflammation

• Localized physical condition from injury.
• Redness, swelling, heat, and pain are common signs.
• Chemicals such as histamine, serotonin and bradykinin are involved.