final exam Flashcards
what type of cancer is processed meat linked to?
21% of bowel cancer
the meat forms N-nitroso compounds such as nitrosamines (which are potent
carcinogens) as they react during the processing, storage and/or cooking process
Are naturally sourced nitrates better than synthetic ones with respect to the “chemistry” of processed meat?
no
It is estimated that eating processed and red meats leads to a ____ % increase in bowel cancer.
21%
What is innate immunity?
Is the immunity we are born with, it includes barriers (skin), phagocytic cells, antimicrobial proteins, the inflammatory response, and natural killer cells.
What are the first barriers/lines of defense of the innate immune system?
skin and mucous membrane, temperature,
low pH and chemical mediators, inflammatory response
Neutrophils, macrophages and natural killer cells are all types of _______ blood cells.
white
What are interferons and how do they protect cells against viral attack?
infected cell produces infron proteins that exocytose from cell and enter another non infected cell and stimulates that cell to produce antiviral proteins to protect itself from infection
What does a Mast cell produce?
histamine
Describe the steps of an inflammatory response
mast cells signal WBC thats theres a problem
capillaries diolate (widen) and become leaky so neutrophils can exit and enter imfection
neutrophils digest bacteria and tissue repairs
What are the three key ingredients of pus?
dead white blood cells,
fluid leaked from capillaries and tissue debris
What can be found in lymph nodes?
Lymph nodes filter substances that travel through the lymphatic fluid, and they contain lymphocytes (white blood cells) that help the body fight infection and disease.
whats the function of the lymphatic sys?
to fight infection and return fluids to circulatory sys
What is the adaptive immune response? what are the 2 types?
activated only after exposure to pathogens
humoral response
cell mediated response
whats the humoral response
antibodies defend against infection in body fluids
whats the cell mediated response in adaptive imm?
the destruction of infected cells by cytotoxic T cells
What is an antigen?
any molecule that provokes imm resppnse
What is an antibody?
a protein dissolved in blood plasma that attaches to a specific kind of antigen and helps to counter its effects.
What do antibodies do?
Antibodies destroy bacteria and viruses, thereby preventing them from entering host cells.
where do B and T cells mature?
B-bone marrow
T-thymus
B cells are responsible for the __________ immune response and T cells for the _______ ___________immune response.
B- humoral
T- cell mediated
how many B and T cells do we have?
100,000
what types of cells do B cells produce after exposure? what are their jobs?
plasma cells- short lived, secrete antibodies to attack
memory cells- long lived, ready to be activated by a second exposure to the antigen.
The first exposure is called a __________ immune response. The next time you are exposed it is a_________ immune response.
primary
secondary
When a cell becomes infected, “self” proteins will bind to the antigen and present it on the surface of the cell. Once noticed by a helper T cell what will happen?
- It will make more copies of itself.
- It will produce signaling molecules to turn on B cells that will produce more antibodies and
- It will activate cytotoxic T cells to kill the infected cells.
Cytotoxic T cells kill infected cells in three basic steps - Describe how this works.
1) A cytotoxic T cell binds to an infected cell.
2) Perforin makes holes in the infected cells membrane, and enzymes that promote apoptosis enter.
3) The infected cell is destroyed (lysed).
what are T cells
Cells created in the thymus that produce substances that attack infected cells in the body.
what are B cells
Cells manufactured in the bone marrow that create antibodies for destroying bacteria and viruses.
what is the flu?
respiratory infection caused by influenza.
transported by droplets
contagious 1-4 days before onset and 5 days after first symptoms
can cause secondary illnesses that could lead to death
If you are throwing up for a day or so, you have probably caught a ______ and if you have diarrhea a_________
Norovirus
Rotavirus
how many people were killed in the spanish and swine flus?
spanish- 500 mill
swine- 20,000
what is the most important thing you can do to prevent yourself from becoming sick
wash your hands
Does the measles mumps rubella (MMR) vaccine cause autism? Why do people think it does?
No, it does not cause autism whatsoever.
People thought it did due to 8/12 kids having symptoms at the time. It got retracted in 2010 as there was no casual link between MMR vaccine and autism.
what are MHC?
Major Histocompatibility Complex molecules.
proteins that recognize our cells as “self”
coded by hundreds of diff alleles
There are 3 ways the immune system can “go wrong” and result in disease?
hyperactive immune system
A poorly functioning immune system
An immune system that attacks itself
what is a hyperactive imm sys
immune system becomes hypersensitive to regular environment (causes allergies, asthma, eczema)
what is a poorly functioning immune system
system fails to recognize irregular cells and allows for their continued growth instead of destruction
causes cancer or AIDS
What is an immune system that attacks itself?
system fails to recognize “self”, causes Rheumatoid Arthritis, Type I Diabetes, Lupus, Psoriasis, IBD, MS etc.
What is an allergy?
imm sys disorder caused by abnormal sensitivity to an antigen
what is an allergen?
a substance that causes an allergic reaction OR an antigen that causes an allergy
what is first exposure to an allergy called? what are the steps? what is it similar to?
sensitization
1 antigen enters bloodstream
2 B cells make antibodies
3 antibodies attch to mast cell
similar to primary imm response
what is later exposure to an allergy similar to?
Secondary immune response
What is anaphylactic shock?
a rapid release of inflammatory chemicals from mast cells, rapidly dilates blood vessels (makes them wider), resulting in a potentially fatal drop in blood pressure.
What is used to counteract the effects of anaphylactic shock?
epinephrin in epipens
what is the Hygiene hypothesis?
bc we live in a relatively clean world in developed countries there is a theory that this may be leading to more allergies Evidence for this hypothesis is that in the developed world we have seen a 3-5% annual increase in various diseases such as allergies
what are diseases that result from an overactive immune system?
allergies, asthma, eczema
what are examples of diseases from a poorly functioning immune system
AIDS,
chrons
asthma
cancer
hepititis
research shows that pollutants can also…
disrupt the imm sys
what diseases are when the imm sys attacks itself
arthritis
lupus
diabetes
Chrohn’s Disease
Parkinson’s Disease
From a health perspective, why should we care about being overweight or obese or chronic stress?
they are all linked to high blood pressure, physical functioning and mental illness issues. Also heart attacks, strokes, lack of motivation, sleep problems, fatigue etc.
40% of men and 28% of women are overweight (BMI of 25 or more)
Obesity rates have tripled since the 1980s.
20% of Canadians adults are obese (BMI of 30 or more)
What is ecology?
the study of how organisms interact with their living (biotic) and non-living (abiotic) environment
Abiotic Factors
nonliving
energy sources, water, temp, air
Biotic Factors
All the living organisms that inhabit an environment
what is the order of ecological study from least to most inclusive
organism, population, community, ecosystem, landscape, biosphere
define: population
community
ecosystem
landscape
biosphere
p- group of individuals of same species living in same place.
c- all pops and living organisms in an enviro
e- all living and nonliving things in enviro
l- many ecosys linked by energy, materials, or organisms
b- earth, sum of all ecosys
Why is it colder at the poles than the equator?
Sun shines at a low angle near to the Poles so heat is spread over a wider area.
What causes our seasons?
the tilt of the earths axis
What is the primary driver of our oceanic and atmospheric air currents?
uneven distribution of solar energy on Earth’s surface. This energy imbalance causes differences in temperature, pressure, and density, which in turn lead to the movement of air and water masses.
How much does temperature change for every 1000 m increase in elevation?
6 degrees C
How does the presence of mountains affect precipitation patterns on the windward and leeward sides of
the mountain?
As the air moves up the windward side of a mountain, it cools, and the volume decreases. As a result, humidity increases and orographic clouds and precipitation can develop. When the air descends the leeward side, it warms and is drier because the moisture in the air was wrung out during the ascent.
In marine and freshwater ecosystems, what is the photic zone?
p- The photic zone marks the depth at which there is enough light for PS.
In marine and freshwater ecosystems, what is the benthic zone?
the bottom sediments. Near shore, these are in the photic zone. Algae and plants can grow
In marine and freshwater ecosystems, what is the pelagic zone?
consists of the water column of the open ocean and can be further divided into regions by depth. can be thought of as an imaginary cylinder or water column between the surface of the sea and the bottom
What is the most diverse marine habitat?
coral reefs
What is an estuary?
where a fresh water stream meets the ocean. The nutrients received from the river make estuaries some of the most productive biomes on earth. Estuaries are home to many oysters, crabs, and fish and many animals reproduce there.
In the summer, in temperate areas, lakes can stratify, with warmer less dense water on top and colder, more dense water on the bottom. What are the top and bottom layers called?
warm layer- in photic zone, called epilimnion
cold layer- hypolimnion
what are the layers of cold and warm water separated by
thermocline, a zone of rapid temperature change
when is temp in lakes uniform? what causes this?
spring and fall
caused by overturn, nutrients from the bottom of the lake get mixed around w oxygen
What are some benefits of wetlands?
filters nutrients and sediments.
natural water quality improvement
flood protection
shoreline erosion control
Terrestrial biomes that are cold and dry =
polar and tundra
warmer and more ppn and with less or no permafrost =
boreal forest
warmer and wetter than boreal forest =
temperate forest
similar temperature to temperate forest, but less water and sometimes fires =
temperate grasslands
very dry areas =
deserts