Immune system Flashcards
Define the term “Immunity”
The ability of the body to defend itself against disease-causing organisms.
Identify the organs, tissues and cells which help the body fight infection.
Organs = the thymus and bone marrow, lymph nodes and vessels, spleen, and skin.
Tissues =
Cells = lymphocytes, macrophages, neutrophils, basophils, mast cells, eosinophils and natural killer cells.
Describe the role of non-specific immunity - including natural barriers.
It protects generically against all pathogens. Non-specific immunity includes physical and chemical barriers that keep harmful materials from entering the body and non-specific phagocytic immune cells that respond to each pathogen using the same mechanism.
Outline the importance of specific immunity.
-Provides protection against one specific substance but no others
-Protect against a specific foreign substance. E.g. Measles virus (a specific pathogen)
-Lymphocytes (B & T lymphocytes) and macrophages play a key role
Explain the term antigen.
Any substance capable of mobilising the body’s immune system and provoking an immune response.
Briefly describe humoral immunity to include the role of B and T lymphocytes.
Humoural immunity = adaptive immune response = from vaccines or having a pathology before. B lymphocytes and the memory cells produce antibodies.
Briefly describe cell-mediated immunity to include the role of T lymphocytes.
-T cells attack antigens directly through cell-to-cell contact
-T cell Function:
1) Ingestion of antigen (pathogen) by a macrophage, macrophage digest antigen & pushed to the membrane surface (antigen presentation)
2) T cells bind to antigens & are activated (T cell activation)
3) T cell divides repeatedly, resulting in large numbers (clones), a group of identical cells formed by the same parent cell
- Four subgroups w/in clone: killer T cells, helper T cells, suppressor T cells, and memory T cells.
Name the different types of antibodies and indicate their major functions.
IgA = Found in saliva, tears, mucus, breast milk and intestinal fluid, IgA protects against ingested and inhaled pathogens.
IgD = This antibody is found on the surface of your B cells. Though its exact function is unclear, experts think that IgD supports B cell maturation and activation.
IgE = Found mainly in your skin, lungs and mucus membranes, IgE antibodies cause your mast cells (a type of white blood cell) to release histamine and other chemicals into your bloodstream. IgE antibodies can cause allergic reactions.
IgG = This is the most common antibody, making up approximately 70% to 75% of all immunoglobulins in your body. It’s found mainly in blood and tissue fluids. I
IgG antibodies help protect your body from viral and bacterial infections.
IgM = Found in your blood and lymph system, IgM antibodies act as the first line of defense against infections. They also play a large role in immune regulation.
6.6 Outline the physiological process of immunity in the context of active and passive immunity.
7.1 Describe the functions of the lymphatic system
- Drains excess interstitial fluid.
- Transport dietary lipids
- Carries out immune responses.
7.2 Describe the structure and function of lymphatic vessels, capillaries and circulation.
Explain the importance of the lymphatic system in the immune response.
The lymph nodes and other lymphatic structures (like the spleen and thymus) hold special white blood cells called lymphocytes.
These can rapidly multiply and release antibodies in response to bacteria, viruses, and a range of other stimuli from dead or dying cells and abnormally behaving cells such as cancer cells.
7.4 Discuss and identify the major lymphoid tissues and lymph nodes.
What is the role of lymphocytes in the immune response?
Antibody production, the direct cell-mediated killing of virus-infected and tumour cells, and regulation of the immune response.
What is the role of macrophages in the immune response?
Following phagocytosis of foreign material, macrophages process the antigen for use by the lymphocytes, thus initiating an immune response. Macrophages also stimulate the proliferation of lymphocytes.
