Chapter 34 - The Immune System and It's Diseases Flashcards
What additives makes bacon carcinogenic and under what circumstances?
Nitrates and nitrites which are not carcinogenic.
BUT when nitrite interacts with certain components in red meat they form N-nitroso compounds that cause cancer.
What carcinogenic compounds can be found in bacon? The most notable of these is…
N-nitroso compounds.
The most notable of these is nitrosamine, which is quite highly carcinogenic.
___% of lung cancers are linked to smoking.
___% of bowel cancers can be linked to eating processed or red meat.
86% of lung cancers are linked to smoking.
21% of bowel cancers can be linked to eating processed or red meat.
What type of cancer is processed meat linked to?
Colon (and other digestive) cancers.
How did the meat industry respond to information that processed meats cause cancer?
They published articles casting doubt on the harmfulness of nitrate and exaggerated the risk from botulism on non-nitrated meats.
In the US and Canada, what does it really mean when meat is labeled as “natural” or “no added nitrates”?
They are NOT free of nitrates/ites, only free of synthetically added nitrates/ites.
Are naturally sourced nitrates better than synthetic ones with respect to the “chemistry” of processed meat?
No. The source of the nitrates and nitrites is irrelevant. Both are converted to the carcinogenic nitrosamines.
It is estimated that eating processed and red meats leads to a ____ % increase in bowel cancer.
21%
What type of diet can increase the effects of nitrosamines on a person’s health?
A diet with few vitamins, fruits or vegetables.
What are some risk factors for colon cancer other than an increased consumption of meat?
The consumption of low fibre diets with few vegetables or whole grains.
What is the immune system?
The body’s defence against disease causing agents.
What is innate immunity?
A type of immunity/defence that is present before exposure to pathogens and is effective from birth. It’s not specific and attacks all foreign invaders.
Innate immune defences include… (5)
Barriers (skin/mucous), phagocytic cells, antimicrobial proteins, the inflammatory response and
natural killer cells.
What are the first barriers/lines of defense of the innate immune response?
Skin and mucous membranes that protect organ systems open to the external environment.
What are phagocytic cells?
Phagocytosis = cell eating. They eat other cells.
Neutrophils, macrophages and natural killer cells are all types of _______ blood cells which are part of the ________ immune response. What do they do?
White blood cells. Innate immune response.
They’re all phagocytic cells that eat microbes, bacteria and viruses. Natural killer cells attack cancer and infected cells by releasing chemicals.
What are interferons and are they part of the innate or acquired immune response?
Interferons are defensive proteins produced by virus-infected cells that help to limit cell-to-cell spread. They are part of our innate immune response.
How do interferons protect cells against viral attack/infection?
They’re made by infected cells, released when the cell dies, enter healthy cells, and turn on genes in the healthy cell that code for proteins which inhibit viral reproduction.
There are about ___ different kinds of proteins that circulate in an inactive form in the blood. How are they activated and what do they do?
30 different kinds. Activated by microbes, resulting in a cascade of steps that lead to lysis of the invaded cells.
What are phagocytic cells and defensive proteins activated by?
They’re activated by particular pathogens getting into the body.
What is a Mast cell and what does it produce?
A type of white blood cell that produces histamine when stimulated to do so.
What are the visible symptoms of the inflammatory response? What causes these symptoms?
The affected area becomes red, warm, swollen and often sore. The local increase in blood flow, fluid, and cells.
What are the steps of a localized inflammatory response (5 steps)?
1 Damaged skin releases alarm signals (histamines). 2 Blood vessels dilate and leak. 3 Neutrophils leave the blood and enter affected tissue to clean it. 4 Pus that often forms and 5 clotting proteins and platelets seal the infected region.
What are the three key ingredients of pus?
Dead white blood cells, fluid leaked from capillaries, and other tissue debris.