Immune Response

Discuss the function of the immune system

The function of the immune system is to protect the body from harmful substances and fight off pathogens.

Describe immune cells and their function

  • Neutrophil - phagocytosis

  • Natural killer cell - nonspecific antigen destruction

  • Dendritic cell - Antigen presenting cell

  • Monocyte - immature macrophage

  • Granulocytes - surrounds and destroys pathogens

  • Macrophage - phagocytosis

Differentiate between innate and adaptive immunity

Innate immunity is something we are born with and the body will respond with. It is non-specific and has no immune memory.

Adaptive immunity is something that adapts over time through memory. It is specific and adaptive to the body’s needs.

Differentiate humoral from cellular immune response

Humoral immunity refers to immunity that involves antibodies/immunoglobulins (B cells). It is adaptive

Cell-mediated immunity involves the use of cells to recognize and destroy pathogens. Uses APCs and cytotoxic T cells.

Discuss the role of T cells and B cells

  • B lymphocyte

    • develop in bone marrow

    • Become active when exposed to an antigen - secrete immunoglobulins - humoral immunity

  • T lymphocyte

    • Matures in the thymus

    • Cellular immunity

    • Cytotoxic T - attacks tumor cells and virus cells

    • Helper T - activates other cells

    • Suppressor T - provides balance

Discuss the role of Immunoglobulins

IgA - Concentrated in bodily secretions

IgG - most common, activates complement, antibody, placenta

IgM - First immunoglobulin to proliferate immune response - bound to B lymphocytes & activates complement

IgD - Bound to and activates B lymphocytes

IgE - stimulates histamine - bound to mast cells

Key terms:

  • Neutralization

    • Binding of antigen to antibody (antigen-antibody complex)

  • Opsonization

    • Promotion of phagocytosis

  • Hypersensitivity

    • Excessive immune response

  • Autoimmunity

    • Cannot distinguish pathogen from self - attacking healthy cells

  • Alloimmunition

    • Rejection of external cells (rejecting blood transfusion/organ transplant)