Immune System - Ch. 24 Flashcards
Who created the first vaccine?
Edward Jenner
What happens when you get a vaccination/immunization?
Your immune system is exposed to a harmless version of a pathogenic microbe, which triggers immune response and creates antibodies.
What is the first line of defense called and what are some of the defenses?
The first line of defense is the EXTERNAL INNATE. It is nonspecific.
- Physical Barriers- outer layer of skin, mucous membranes, nose hair, etc.
- Chemical Defenses- stomach acid, sweat, saliva, etc.
What is the second line of defense called and what are some of the defenses?
The second line of defense is the INTERNAL INNATE. Some of the internal defenses are:
- Macrophages- phagocytic white blood cells that patrol the blood and engulf bacteria and viruses
- Natural Killer (NK) Cells- white blood cells that destroy infected cells. It releases a chemical called perforin.
- Interferon- a protein that interferes with viral growth
- Complement Proteins- causes cell to lyse
What is the third line of defense called and what are some of the defenses?
The third line of defense is the ADAPTIVE DEFENSES.
Humoral Reponse:
1. B Lymphocytes/B Cells
-produces antibodies
-circulates in blood and lymph
2. Clonal Selection
-B cells encounter antigens (foreign substances)
-Antibodies secreted, circulate in blood stream
-produces memory cells
Explain the Temperature Response
- Macrophages send message to brain to raise body’s temperature
- Create pyrogens which travel to hypothalmus; stimulates fever
- Fever inhibits microbial growth
Explain the Lymphatic System
It fights infection and contains lymph nodes (saclike organs packed with white blood cells), a network of vessels, and lymph (fluids)
Explain the Inflammatory Respponse
- When there is a tissue injury, chemical signals are released.
- Dilation and increased leakiness of local blood vessels; migration of phagocytes to area
- Phagocytes engulf bacteria and cell debris
- Tissue heals!
What is an antigen? What is an antibody?
An ANTIGEN is a foreign substance that elicits an immune response. An ANTIBODY is a protein that binds to a particular antigen; it consists of 4 polypeptide chains and has a Y shape. The tip of the Y is the antigen receptor.
What are memory cells? (Note: memory cells are produced during clonal selection)
rapid secondary immune response upon subsequent exposures; can last decades
Which is faster, the primary or secondary immune response?
Secondary. It peaks in 2 - 7 days as opposed to 10 - 17 days.
What are T cells? What are the 2 types of T cells?
T cells respond to pathogens that have already entered body cells. The 2 types are:
- Helper T Cells– macrophage displays self & nonself proteins on surface to alert Helper T Cells. Activated Helper T Cells now go through, stimulates 3rd line of defense, and activates cell-mediated immune response.
- Cytotoxic T Cells– binds to infected cell, produces perforin, and cell death is the result (apoptosis: programmed cell death)
What’s the difference between active immunity and passive immunity?
Active immunity: -Body stimulated to produce antibodies -e.g., exposure to antigen, like getting sick or vaccinated -Permanent Passive immunity: -Receive premade antibodies -Temporary -e.g., antivenin, nursing infant
What happens when you have an autoimmune disease?
Your immune system can’t distinguish self from nonself cells and thus the body attacks own tissues.
What are allergies?
Your body mounts a major defense against a harmless substance. Caused by overactive immune system. Severe allergies occur when inflammatory response is too fast and body goes into anaphylactic shock.
