Chapter 12

Lymphatic System- works to assist circulation and plays a role in the body’s defense system. Made up of two parts, lymphatic vessels, and lymph tissues and organs.

Lymphatic Vessels- form a network of vessels that surround blood vessels, allowing for a one way flow towards the heart.

lymph-

lymph capillaries-

Right lymphatic duct-

Thoracic duct-

Lymph Nodes- collections of lymph tissue that cluster along the lymph vessels.

-rids lymph of harmful materials (bacteria, viruses, foreign substances)

-large clusters of lymph nodes are found in the cervical, axillary, and inguinal regions.

-kidney-shaped, less than 1 inch long, “buried” within connective tissue.

Other Lymph Organs

Spleen-

Thymus-

Tonsils-

Peyers’s Patches-

-MALT (mucosa-associated lymphatic tissue)

Nonspecific Defense System- responds immediately to protect the body from all foreign substances.

First Line of Defense

Surface Membrane Barriers-

Second Line of Defense

Cells and Chemicals

Phagocytes-

Natural Killer Cells-

Inflammatory Response- triggered when tissue is damaged or infected

-cause redness, heat, swelling, pain

Complement-

Interferon-

Fever-

-

Specific Body Defenses- The Immune System -- Third Line of Defense

Immune System- recognizes foreign molecules (antigens) and acts to inactivate or destroy them.

3 important aspects of the immune response:

1. antigen specific-

2. systemic-

3. memory-

Two overlapping arms of immunity

Humoral immunity-

Cellular immunity-

Antigens- any substance capable of exciting the immune system and provoking an immune response.

Haptens- incomplete antigens, small molecules combined with proteins can trigger an attack.

Cells of the Immune System

B lymphocytes- B cells-

T lymphocytes- T cells-

Macrophages-

Antigen Presenting Cells-

Humoral Immune Response-

-When an immature B cell binds to a recognized antigen, it becomes activated:

-Types of Acquired Immunity

Antibodies- immunoglobulins-

-All antibodies have the same basic structure

-5 different classes: IgG, IgE, IgD, IgM, IgA

-antibodies work to inactivate antigens, in various ways

Cellular Immune Response-

-T cells must bind to an antigen that is “presented” by a macrophage:

Killer T cells-

Helper T cells- directors of the immune system.

Regulatory (Suppressor) T cells-

Organ Transplants and Rejection

-autographs

-isographs

-allographs

-xenographs

Autoimmune Diseases

-Multiple Sclerosis

-Myasthenia Gravis

-Grave’s Disease

-Juvenile Diabetes Mellitus

-Systemic Lupus Erythematosus

-Glomerulonephritis

-Rheumatoid Arthritis

Allergies- abnormal and vigorous immune response in which tissue damage can occur.

-Most common is immediate hypersensitivity, release of histamine, causes:

-Anaphylactic Shock-

-Delayed hypersensitivities-

Immunodeficiencies

-SCID-

-AIDS-

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