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Chapter 31 Flashcards

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Biology 101 flashcards
1
Q

infectious disease

A

a disease caused by a pathogen

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1
Q

pathogen

A

disease causing organisms or viruses
- they inlude certain bacteria protozoans fungi worms and viruses

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2
Q

louis pasteur

A

conducted a series of experimnts inolving microorganisms (yeasts) responsible for alchoholic fermentation. he discovered that other microorganisms could contaminate fermenting beer or wine and these contaminations could interefere with the normal fermentation process

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3
Q

joseph lister

A

hypothesized that microorganisms caused infections. his experiments involved suing carbolic acid to wash instruments and the surgeons hands in order to kill any microorganisms before operations and as a result deaths from infection after surger plummeted.

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4
Q

robert koch

A

developed a proess to identify numerous specific pathogens such as differenet bacteria that cause anthrax and tuberculosis.
it involved takng samples of suspected patogens from diseased animals, in this case, tuberculosis and anthrax which would be caused by bacteria. these bacteria cultures would be allowed to develop into colonies and upon inspection and identification under a microscope, the susepcted pathogen would be injected into a healthy animal, here, mice. the mice then became diseased and new cultures of the suspected pathogen would be extracted from the disesed animal, grown into colonies and identified, if it was the same pathogen, then that specific pathogen may be directly attributed to the illness

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5
Q

athletes foot

A

-fungus
-physical contact with fungus on shoes, floor etc

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6
Q

trichinosis

A

-worm
-eating undercooked pork

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7
Q

common cold

A

-virus
-physical contact or inhalation of airborne droplets

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8
Q

african sleeping sickness

A

-protozoan
-bite of a tsetse fly

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9
Q

lyme disease

A

-bacterium
-bite of infected tick deer tick
-fatigue, joint pain, muscle pain and nervous tissue damage
-ticks feed by penetrating the skin of a host and slowly taking in blood and if a tick is infected with the bacteria that causes lyme diseases and bites a human, the bacterium may be transferred
-can be treated with antibiotics if caught early

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10
Q

cholera

A
  • bacterium
  • drinking contaminated water or eating contaminated food
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11
Q

aids

A

-virus, hiv
-sexual contact

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12
Q

germ theory of disease

A

infectious dieases are caused by pathogens that can spread the diease from one organism to another

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13
Q

how can viruses be transmitted

A

a virus can be transmitted by physical contact; a virus can be transferred from an infected persons hand to yours and then if your hand touches your nose mouth or eyes you can transfer the virus to the mucous membranes which are ideal locations for the virus to invade cells and multiply

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14
Q

how many lines of defense does the body have

A

3

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15
Q

first line of defense

A
  • barries both physical and chemical
    -the bodys first line of defense against pathogens consists of phycial and chemical barriers that prevent pathogens from entering the body
    -these barriers act nonspecifically
    -made up of skin and mucous membranes
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16
Q

nonspecific defenses

A

defenses that do not distinguish one invader from another

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17
Q

skin

A

the skin is one of the physical barriers of the first line of defense that protect the body against the invasion of pathogens nospecifically
- the outer layer of the skin is comprised of tough dead cells hat most bacteria and other organisms cannot penetrate. this layer is also always shedding which makes it difficult for bacteria to embed in it and grow
-the skin also contains sweat and oil glands which secrete acids and oils that prevent the growth of many organisms, acting as a chemical barrier. sweat also contains lysozyme, an enzyme that breaks down the cell walls of many bacteria
-more chemical barriers include saliva and tears contain lysozyme which helps protect the mouth and eyes, especially suscptible areas, from bacterial invasion

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18
Q

mucous membranes

A

the digestive and respiratory tracts are lined with mucous membranes. mucus in the trachea for example, create sticky barreirs that trap microorganisms, cilia move these trapped partciles up tp the pharynx where tehy are swallowed and ater destroyed by the enzymes and acidws found in the stomach

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19
Q

second line of defense

A

-pathigens will always be present in the environemnt and may nyo always be stopped by the first line of defense, which may happen by an insect bite, pin prick or any other brekaing of skin which allows pathogens to penetrate phycial barriers and enter the body, the second line of defense confronts invaders nonspecifically with certain pathogen detsroying white blood cells, speciliased proteins and the inflammatory response

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20
Q

white blood cells part of the second line of defense

A

certain whit eblood cells roam through the bloodstream, including the inetrstitial fluid and lymphatic system, attacking invaders. some whit eblodo cells such as macrophages and neutrophils detsroy invaders through pahgocvytosis, maiing them phagocytes. neutrophils macrophages and natural killer cells

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21
Q

macrophages

A

-big eaters
-found mainly in interstitial fluid
-phagocutosis; upon encounrting a pathogen it englifs it. the pathiegn is drawn into the macrophage where the seceted enxymes such as lysozyme kill the pathogen

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22
Q

neutrophils

A

-smaller
-more numerous than macrophages in the
-phagocytes
-once the pathogen is inside the nutrophil, the neutrophil releases chemicals which are similar to bleach to kill the invading pathogen, however, these chemicals kill the enutrophi as well

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23
Q

how do wbcs protect the identify invaders

A

the responses produced by wbs is due to its ability to identify which structures to attack, and which to leave alone. white blood cells can identify certain proteins and carbohydrates on the surfce of an invading pathogen. recognizing these foregn molecules triggers the cells’ responses

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24
Q

natural killer cells

A

-unlike other wbcs incolved in the second line of defense, nk cells do not attack pathogens directly or kill by phagocytosis.
-they rcognize body cells that have become infected by a virus and kil them by releasing chemicals that poke holes in the infected cells membrane.
-nk cells also recognize and kill abnormal body eclls such as cancer cells, they thusplay a key role in defending against cancer by killing abnormal body cells before they develop into a tumor.

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25
Q

inflammatory response

A

-At the site of pathogen invasioncertain cells release a variety of chemical “alarms.” These chemical alarms trigger an inflammatory response.
-cells called mast cells release a type of chemical alarm called histamine, which causes nearby blood vessels to dilate (expand).
-The expanded blood vessels increase the volume of blood flowing to the injured tissue. In addition, the vessels become more porous, allowing more blood plasma to leak into the interstitial fluid. Other chemicals attract additional phagocytes and other white blood cells to the area, where they pass through the leaky blood vessel walls into the interstitial fluid.
-This local increase of blood flow, fluid, and white blood cells produces the redness, heat, swelling, and pain you may experience around the injured area.

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26
Q

inflammatory response def

A

a nonspecific defense characterized by redness, heat, swelling, and pain.

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27
Q

function of the inflammatory response

A

The major function of the inflammatory response includes removing pathogens and cleaning injured tissues. Inflammation may occur in a tiny area, such as the site of a mosquito bite.

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28
Q

general inflammatory response

A

if pathogens get into the blood or release toxins that are carried throughout the body by the circulatory system, the whole body may react with an inflammatory response. In such a response white blood cells increase and a fever (an abnormally high body temperature) may occur. A very high fever may be dangerous, because it can denature proteins and cause other damage. But a moderate fever may contribute to defense by stimulating phagocytosis and stopping the growth of many kinds of microorganisms.

29
Q

specialised proteins

A

-Other internal nonspecific defenses include specialized proteins that either attack invaders directly or block their reproduction.
-interferon, are a family of proteins produced by cells in response to becoming infected by a virus. The infected cell may die, but its interferon reaches healthy cells in the area, stimulating them to produce proteins that interfere with virus reproduction.
-Interferon is effective against many viruses and is therefore nonspecific. Interferon seems to be effective against viruses that cause the flu and the common cold.
-The body can only produce interferon in small amounts.
However, the recombinant DNA technology has enabled the drug industry to manufacture interferon in large quantities to be used to treat certain viral infections.

30
Q

what is the third line of defense and how does it function

A

-the third line is specific, or targeted, defense.
-to accomplish this, the immune system must be able to distinguish between its own body cells (“self”) and intruders (“non-self”).
-when non-self cells or other intruders are identified, the immune system launches a customized response
-Such a response may take longer, but it is longer-lasting and often more effective than nonspecific defenses.

31
Q

immunity

A

immunity means that yourbody is resistant to the pathogen that causes a specific disease

32
Q

how does one acquire immunity

A

one acquires immunity by becoming infected by the pathogen that causes a specific disease

33
Q

antigen

A

an antigen is a large molecule, usually a protein that provokes an immune response. the surfaces of viruses, bacteria, cancer cells, pollen, fungi and other such cells conntain certain molcules called antigens

34
Q

antibody

A

proteins found on the surface of certain wbcs (b and t cells) or in blood plasma that atach to particular antigens

35
Q

strcuture and function of antibody

A

-the most common antibodies are y shaped molecules
-at the tip of each arm of the y is an antigen binding site, or antigen receptor
-the shape of the antigen receptor makes it possible for the antibody to recognize a specific antigen with a complementary shape
-each antigen sits on the surface of the invading partcile and has a particular shape with knobs that protrude from the surface.
- these kbons, also known as markers, are unique for each antigen. and so, a specific antigen marker fits into a specific antibody

36
Q

how is the body able to targeta large variety of pathogens

A

there is a huge variety in the three dimensiaonal shapes of antigen binding sites found on the body’s antibodies and so this variety gives antibodies the ability to recognise an equally large variety of antigens

37
Q

in what ways do antibodies work

A

rather than directly engulfing pathogens, natibodies work indirectly in destroying them. an antibody “tags” the invader by binding to the antigen molcule whioch triggers mechanisms that neutralise and destroy the invader
1- the binding of antobodies stops viruses from atrtaching to a host cell. this disables the virus and halts further infection
2- an antibody might bind to the toxin-producing moleucles on the surface of a bacteria cell. this makes the pathogen harmless and tags it for destruction by phagocytes
3- antibodies may cause pathogens to clump together which makes the cells easy targets for phagocytes to capture and destroy
4- antibodies may also activate immune system chemicals called complement proteins that can attach to virasl surfaces or bacterial memebranes. these proteins also help to clump viruses for phagocytosis by wbss or puncture holes in a bacterial outer membrane, causing the pathigen to break open.
all of these antibody mechniams involve a specific recognition and attack phase followed by a nonspecific destruction phase

38
Q

lymphocyte

A

a wbc that recognises a specific invader
-originate in the bone marrow from stem cells

39
Q

b cells

A

-b lymphocytes continue their develpoment from in the bone marrow
-travel in the blood to the lympth nodes and other parts of the lymphatic system
-involved in humoral immunity
-primarily defend against bacteria and viruses found outside of cells in bodily fluids
-antibody proteins are embedded on the surface of B cells
-there are approximatelty 100 million different B cell surfaces

40
Q

t cells

A

-t lymphocytes are formed transported to the thymus gland where they mature from stem cells
-travel in the blood to the lympth nodes and other parts of the lymphatic system
-incolved in cell mediated immunity

41
Q

development of lymphocytes

A

during the development of lymphocytes, many different antigen receptors are generated.
However, the body destroys those lymphocytes with antigen receptors that could react against the body’s own molecules and cells. Thus, the immune system can distinguish self (the body’s own cells) from non-self (foreign substances).
B cells

42
Q

b cells and humoral immunity

A

-when fighting a pathogen, a B cell containing the matching antign recepto binds to the antigens of the pathogen. this actiavtyes the b cell.
-activation means that the b cell grows and clones itself forms millions of identical cells
-each of those cells in capable of developing into a plasma cell which prodces and secretes antibodies specfici to the antigen that acivated the orginal b cell
-the plasma cells are carried in the lymph and blood to sites of infection throughout the body.
-since antibodies tavel in blood and other bodily fluids immunity that orginates form b cells is called humoral immunity because the bodily fluids were once called humours

43
Q

t cells and cell mediated immunity

A

-T cells work by directly attacking host cells that contain multiplying bacteria or viruses. These host cells are actually body cells that have become infected.
-Since T cells attack other cells, they produce a type of immunity called cell-mediated immunity.
-Each T cell has receptors for a specific antigen. When a pathogen infects a body cell, the pathogen’s antigens are displayed on the surface of the body cell. Those antigens bind to the receptors of the “matching” T cell, which activates the T cell.
-The activated T cell then divides and produces millions of identical clones. These clones develop into cytotoxic T cells, which then attack cells infected with the pathogen that triggered the response.
-Cytotoxic T cells bind to an infected cell’s membrane and poke holes in it by secreting a protein called perforin (think “perforate”). The infected cell leaks fluid, breaks open, and dies.

44
Q

t cells and cancer

A

-Research indicates that individuals with weakened immune systems are more likely to get cancer. This suggests that the immune system is important in fighting some cancers.
-Certain B cells play a role in this battle.
-Researchers are studying how T cells may also be involved. They have learned that some changes that lead to cancer occur on the outer membrane of body cells. Scientists have hypothesized that the altered membrane may alert T cells to an intruder in the body. Cytotoxic T cells then proceed to destroy the cancer cells

45
Q

helper t cells

A

Both humoral and cell-mediated immunity get a boost from a particular type of lymphocyte called helper T cells. Like all lymphocytes, helper T cells are present in many versions, each with surface receptors that recognize a specific antigen
-Like cytotoxic T cells, the helper T cells are activated by binding to cells that display antigens of a pathogen. But the antigen-displaying cells that helper T cells recognize are macrophages, the white blood cells that eat pathogens by phagocytosis.
-The marked macrophages serve as an “announcement” that a pathogen is present. Helper T cells respond to this announcement by secreting chemicals that activate both cytotoxic T cells and B cells.

46
Q

secondary imune response

A

-A second exposure to the same pathogen triggers a much quicker and stronger response called the secondary immune response.
-The B and T memory cells for that pathogen recognize and quickly respond to this repeat visit.
-The second exposure stimulates the memory B cells to rapidly produce plasma cells that will secrete antibodies specific to that antigen.
-Meanwhile memory T cells rapidly produce large numbers of cytotoxic T cells that attack cells infected with the pathogen. -The process is so quick that you don’t develop symptoms of the disease. Your body destroys the invader before you feel sick.

47
Q

primary immune response

A

-When you are first exposed to a pathogen, specific B and T cells multiply and defend against that particular pathogen.
-Some of that “brand” of B and T cells remain in your body. These long-lasting lymphocytes are called memory cells.
-The first formation of B and T cells to battle a new invading pathogen is called the primary immune response. This first response is relatively slow and weak because time is needed for enough specific lymphocytes to form to defeat the pathogen.

48
Q

allergy

A

an abnormal over-sensitivity to an otehrwise non-harmful antigen, called an allergen

48
Q

how are allergies treated

A

one treatment for allergies is a class of medication known as antihistamines which block the action of hustamine minimizing the symptoms of an allergic reaction

48
Q

how does a pollen allergy, or hay fever work

A

-the pollen grains have allergens on their surface that trigger b cells to produce a class of antibodies different from those that protect against pathogens.
-these allergic antibodies attach to receptor proteins on the surface of mast cells that produce histamine which brings about the the inflammatory response,
-thus leading to the sympyoms of allergies, including water eyes, a runny nose. this is because the histamine dilates local blood vessels which reuslts in more liquid filling the interstitial area of the eyes and nose

48
Q

autoimmune disease nwith examples

A

in a case in which the immune system turns againts some of the bodys own molecules, and cannot distinguish between self and non self, an autoimmune disease has developed
examples: lupus, rheumatoid arthritis, multiple sclerosis

48
Q

lupus

A

-occurs when the body makes antibodies that react with some of the bodys own tissies as if they were foreign
-since any tissue or rogan of the body can be attacked symptoms of the disease are varied. (fever, weak-ness, weightloss, anemia, a butterfly shaped rash on the face)

48
Q

rheumatiod arthritis

A

-characterized by the formation of antibodies that attack the bodys own tissues.
-the immune system atatcks cartilage and bone joints causing damage and painful inflammation
-when rheumatoid arthritis inflicts someone under teh age of 16 it is referred to as juveline rheumatoid arthritis

48
Q

dangerous allergic reaction

A

some people, once ingesting something they are severely allergic to , experience a sudden dramatic drop in blood pressure and have difficulty breathing. this is a dangerous form of allergic reaction called anaphylatic shock and is a potentiuially fatal condition. some people whjo are severly allergic to bees often carry a self injection kit containing epinephrine (adrenaline) a hromone that counteracts the allergys symptoms

49
Q

treatments for autoimmune diseases

A

medicines for autoimmune diseases generally replace the edstroyed self molecules, suppress the immune response or treat specific symptoms

49
Q

contributing factors to teh development of autoimmune diseases

A

genetics, exposure to toxic chemicals, certain viruses

49
Q

why is hiv deadly and how odes it attack the bodt

A

-HIV is deadly because it destroys the immune system.
-HIV infects a variety of immune system cells, especially helper T cells.
-When HIV destroys the body’s helper T cells, the immune system cannot activate other T cells or B cells.
-Both the humoral and cell-mediated immune responses are impaired, and the body cannot fight pathogens.
-Death usually occurs from another infection, such as pneumonia, or from certain types of cancer.

49
Q

is aids curable and if not, why

A

-At present AIDS is incurable, although newly developed drugs have slowed the progress of AIDS in infected individuals and decreased the number of deaths in the United States.
-Unfortunately, HIV mutates frequently and evolves rapidly. This makes the development of a vaccine difficult, since the mutated forms of the virus have different antigens. At pre-sent, education about preventing infection remains the best weapon against AIDS.

49
Q

how is aids trasmitted

A

-The AIDS virus is transmitted mainly in semen and blood.
-It can enter a person’s body during sexual contact or via needles contaminated with infected blood.
-Screening of donated blood has reduced the risk from transfusions, but sharing needles to inject illegal drugs remains a major risk.
-The rate of new infections also continues to rise among sexually active people.

50
Q

HIV stands for

A

A virus called HIV, or human immunodeficiency virus, causes AIDS.

50
Q

multiple sclerosis

A

-an autoimmune disease that strikes the central nervous system
-t cells attack the myelin sheaths that cover the axons of some neurons. the myelin sheath plays a key role in the transmission of nerve signals.
-dirsuptions of teh signals can cause mild symptoms such as fatigue tingling and numbness and more advanced cases may interfere with walking talking memory and concentration

50
Q

AIDS stands for

A

AIDS stands for acquired immune deficiency syndrome. and is caused by HIV

51
Q

organ transplant

A

-an organ trasnplant replaces a damaged organ or part of an organ with a healthy organ or tissue
-just about every time a transplant oiccurs, the recipients body wages a battle agiants the transplanted organ. thsi reaction is the normal process of self/non-self recognition. the trasnplanted organ is identified as non self and triggers an immune response`

52
Q

which organ trasnplants are the least complicatve

A

transplants that arise th fewwest complications are those bwteen iodentical twins or idf the transplant is iwthin the same individual, like a skin graft. this is because the immune system is more likely to to recognise genetically similar tissue as self tissue

53
Q

drugs involved in transplants

A

in all transplants medications are neecssary to suppress the immune response to foreign organs. cyclosporine is a drug commonly used to suppress the immune system and decrease the possibility of rejection.
however, suppressing the immune system increases the patients risk of infection.

54
Q

why are vaccines necessary

A

-antigens of the pathogen stimulate an immune response and among otehr results memnopry cells are formed that reside within the body and provide lasting resistance to that specific pathogen
-however, some pathogens can cause serious illness or death as a result of the first exposure, for these pathogens or when a persons immune sytem is weakened, natural immunity is not much help.
-for some of these diseases a vaccine can stimulate the immune response and formation of memory cells before exposure to the real pathogen

55
Q

vaccine

A

a dose of a pathogen or part of a pathogen that has been disabled or destroyed so it is no longer harmful

56
Q

how are vaccines made

A

-some vaccines are made from just the antigens of the pathigen. the antigens in the vaccine stimulate the immune response
-other vaccines are created by grinding up for heating the dangerous pathogen so it is no longer functional
-some vaccines consists of a slihtly different version of the pathogen that “fools” the bopdy into reaction as if exposed to the real antigen

57
Q

why are booster necessary

A

-the booster is an additional dose of an antigen that “boosts” antibody production and extends the memory for that antigen.
-the booster is necessary because some of the initial memory cells that were produced after the first shot have died

58
Q

active immunity

A

Whenever your body produces antibodies against infection, the result is called active immunity. Active immunity can develop from catching a disease or from receiving a vaccine

59
Q

passive immunity

A

-when your body receives antibodies for a particular disease from another source, the result is called passive immunity.
-For example, a fetus receives antibodies by transfer from the mother’s bloodstream to its own.
-In another example, travelers to some foreign countries receive various shots containing antibodies rather than antigens.
These antibodies temporarily protect the travelers in the event of exposure to particular diseases, such as various forms of hepatitis, in the country they will be visiting. Passive immunity only lasts a few weeks or months because the antibodies in the shots disintegrate over time, and the recipient does not make his or her own antibodies against that pathogen.

Bio (6 decks)

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