B4-2 Immunity Review Flashcards
What is the lymphatic system?
-Network of vessels with associated glands or nodes throughout the body
-lymph vessels collect a fluid called lymph (made of interstitial fluid)
What are the 2 main functions of the lymphatic system?
- Helps to maintain balance of fluids in the body
- Lymphocytes (certain white blood cells) mature and macrophages are stored in the lymph nodes
What is the first line of defence?
-Mainly physical defence which includes the skin and mucous and cilia of the respiratory tract
-chemical provided by the stomach and lysozyme (enzyme in tears)
What is the second line of defence?
-Cell-mediated non specific if the invader resides in the body
-neutrophils, monocytes, and macrophages (WBC) kill bacteria using phagocytosis
-natural killer cells target the body cells that are cancerous or infected with viruses
What is phagocytosis?
-Process where one cell ingests another cell
What is the third line of defence?
-Antibody-mediated specific
-lymphocytes: respond to foreign invaders and antigens; are antibody producing WBC
-T-cell produced in the bone marrow and stored In the thymus (gland near the heart): identifies the invader and passes info to the B-cells
-B-cell produces a single type of antibody: eventually released from the bone marrow to the circulatory system
Describe antibodies
-Y shaped proteins designed to target foreign invaders
-specific, tails of antibody are similar, variation exists at the outer edge of each arm
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What is the antigen-antibody complex?
-Binding of antigens and antibodies in the immune system
-identifies by the macrophage
-attachment increases the size of the complex
What does the helper T-cell do?
-Must read a blueprint of the invader before the B cells produce antibodies
-blueprint is saved even after the invader is destroyed
-immunity is based on maintaining adequate numbers of antibodies
What do killer T-cells do?
-Bind with infected cells and puncture a hole in their membrane
What do suppressor T-cells do?
-Make sure T-cells and B-cells don’t attack normal body tissue
What do memory T-cells do?
-Holds an imprint of the antigen(s) which characterize the infection
-allows the body to act quickly if the antigen is present again
Describe allergies
-Occur when the immune system mistakes harmless cells for harmful invaders
-tissue swelling, mucous secretions and constricted air passages are all part of the immune response
What is an autoimmune disease?
-The suppressor T-cells do not suppress the T or B cells
-Attacks itself
Explain what vaccines do
-Dead (mostly) forms of the virus are injected into patients
-essentially injecting antigens into the patient
-immune system builds antibodies to combat the virus
-patient doesn’t get ill because the virus is dead (or very mild symptoms)
