Immune System Flashcards

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1
Q

Communicable Diseases

A

Caused by Micro-Organisms (virus, fungus, bacteria). Trasmitted from one person to another

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2
Q

Pathogens

A

Disease causing organisms. Defence against pathogens are specific and non specific

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3
Q

Pathogens - Specific

A

Work against selected Pathogens

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4
Q

Pathogens - Non Specific

A

A generalised responce against all pathogens, infections or injuries

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5
Q

Bacteria

A

Microscopic livign organism (1 celled) found everywhere. Can be dangerous or beneficial

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6
Q

Pathogenic bacteria

A

Enter body via different ways - mouth or cut skin. Able to multiply (sufficiently = infection). By bacteria themelves or toxins they produce

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7
Q

Bacteria structure - capsule, cell wall, plasma membrane, cytplasm, dna, flagellum

A

Capsule: Protect cell, Cell wall: Protect & give shape, Plasma membrane: Controls movement in and out of cell, Cytoplasm: Organells and cytosol - live activities occur, DNA: Genetic instriction, Flagellum: Allows Movement

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8
Q

Bacteria reproduction

A

Binary Fission -> Bacteria split into two

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9
Q

Conditions to reproduce

A

Warm temperature, protien rich environment, neutral/ slight acidic ph (some excemptions occur)

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10
Q

Viruses

A

10 - 100 times smaller than bacteria.

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11
Q

Virus multiplication

A

Only within living cells of a host - target specific tissues.

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12
Q

Virus examples

A

Influenza - respiratory tract, Hepatitis - Liver, Poliovirus - motor neurons and spinal cord

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13
Q

Virus - Flu

A

Lock onto target cell in respiratory system & enter cell. Use cell as a factory as they take over it, produce millions of copies which come streaming out. Infect other cells or escape body. Taking over cell kills host cell - inflamtion

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14
Q

Virus structure

A

Spike proties: for attachement to specific cell receptors, Envelop: Protective outer layer, Protien coat: surrounds genetic material, Dna: Genetic instructions

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15
Q

Transmission of pathogens

A

Through direct/indirect means (Sti’s), transfer of bodily fluids, infection by droplets, ingestion of contaminated food/drink, airborne transmissions or by vectors.

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16
Q

Defencce of our body

A

Keep microbes out of the body. Non specific attack on microbes. Specific attack on microbes.

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17
Q

First line Defence

A

The first line of defence is that the body takes against pathogens is to prevent their entry into and reproduction insdie human body.

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18
Q

External defences

A

Ear, eyes, mouth, trachea, stomach, vagina, nasal cavity, skin, urethra, anus

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19
Q

Ear - defence

A

Cerumen inhibits bacteria growth

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20
Q

Mouth cavity - defence

A

Mucous membrane traps microorganisms and mouth cleaned by saliva

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21
Q

Trachea + bronchi - defence

A

Mucous layer traps microorganisms

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22
Q

Stomach - defence

A

Acidic juices kill many microorganisms

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23
Q

Vagina- defence

A

Acidic secretion inhibits growth of pathogens

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24
Q

Nasal cavity - defence

A

Hairs and mucus trap microorganisms

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25
Q

Skin - defence

A

an impervious barrier. Large amount of bacteria on skin - difficult for new pathogenic establishments

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26
Q

Urethra - defence

A

Urine flow prevents bacterial growth

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27
Q

Anus - defence

A

Mucous membrane traps microorganisms

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28
Q

Mucous membranes

A

FOund in digestive, urinary, respiratory and urogenital tracts - line body cavities and inhibits entry of micro organisms

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29
Q

Hairs - defence

A

Trap micro organisms

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30
Q

Cilia

A

Found in respiratory tract. Tiny microscopic hair like progections. Moves muccous towards throat.

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31
Q

Acids

A

Found in stomach, vagina and sweat. kills microorganisms ingested w/ food or in mucous.

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32
Q

Lysozyme

A

Enzyme that kills bacteria. Lysozyme -> enzyme created byy lysosomes. Found in tears, saliva, sweat, nasal secretions, tissue fluid.

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33
Q

Cerumen

A

Found in outer ear, slightly acidic and contains lysozymes.

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34
Q

FLushing action

A

Occurs in urine flowing through urethra, tears, sweat and saliva. - cleansing action

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35
Q

Protective reflexes

A

Sneezing, coughing, vomiting, diarrhea

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36
Q

Sneezing

A

Irritation of walls of nasal cavity - forceful expulsion of air from lungs

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37
Q

Coughing

A

Irritation of respiratory tract - bronchi/bronchioles. Air forced from lungs.

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38
Q

Vomiting

A

Psychological - excessive stretching of stomach - muscles of abdomen and diaphragm contract. stomach contents expelled.

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39
Q

Diarrhea

A

Irritation of small/large intestines by pathogens. Increased peristalsis to remove irritant.

40
Q

First line defence successfulness

A

Not always successful - burns and cuts reduce effectiveness. If 1st fails, move onto third and second defence

41
Q

Second line of defence

A

Phagocytic leukocytes, antimicrobial protiens, inflammatory responce, fever.

42
Q

Non-specific defence

A

Consists of lymph nodes, vessles, lymphoid tissues and different leucocytes.

43
Q

Lymph vessel structure

A

Like veins - squeezing action and valves

44
Q

Lymphatic system

A

Drains intercellular fluid back to the heart and circulatory system.

45
Q

Leucocytes - WBC

A

Different types - all leave the blood capillaries and migrate to place of infection/injury

46
Q

Types of leucocytes

A

Macrophages + Lymphocytes (B+T cells)

47
Q

2nd line of defence - Phagocytosis

A

Any WBC that is capable of engulfing and digesting micro-organisms and cell debis = phagocyte. eg macrophages

48
Q

Macrophages

A

Involved in specific + non specific defence. - carry out phagocytosis, release substances to destory pathogens

49
Q

Lymphocytes - B+ T cells

A

Involved in specific and non specific defence. Produced in bone marrow and some lymphoid tissue - curculate through tissue, blood + lymph

50
Q

Inflammation

A

Responce to tissue damage. Reduce spread, destroy and stop further entry of pathogens.

51
Q

Inflammatory responce - steps

A
  1. when cell damage occurs, cells release histamine and heparine into intercellular fluid.
  2. Histamine increases blood flow to area - increase capilary permeability + blood vessles dialate.
  3. Leaking fluid from blood vessles causes swelling
  4. Increased blood flow causes heat and redness
  5. Heparin prevents immediate clotting.
  6. Phagocytes (macrophages + leucocytes) move to conduct phagocytosis.
  7. Pain receptors stimulated by abnormal conditions
52
Q

Fever

A

Increase body temperature

53
Q

Normal body temperature

A

Aprox 37.5 degrees celcius

54
Q

Increased body temperature

A

Increases heart rate and blood flow. therefore speed of lymphocytes reaching area of infection.

  1. Non optimum condition of pathogen - death
  2. Increase production of T cells
  3. Increase metabolic rate - healing.
55
Q

If temperature is to high

A

Enzymes denature. Harmful if temperature gets to 44-45 degrees.

56
Q

When pathogen enters the body

A

Releases a chemical Interleukin 1 causes the hypothalamus to increase body temperature. Macrophages engullf pathogen

57
Q

Conditions at normal body temperature when fever starts

A

Feel cold, responds by shivering, piloerection (goose bumps) and vasoconstriction of the blood vessles (pale) to warm up

58
Q

Fever broken

A

Infection is over - no more pathogens and hypothalamus resets to 37.5. Temperature is to hot and Vasodilation occurs and sweatingS increases.

59
Q

Specific defences

A

Recognizes foreign molecules and acts to inactivate/destroy them

60
Q

3 important aspects - Specific defences

A

Acts against specific pathogens, not restricted to inital infection site, recognizes and launches stronger test on previous encountered pathogen

61
Q

Antigen

A

Any substance capable of causing a specific immune responce - protien, carbohydrates, virus, pollen etc

62
Q

Self - Antigens

A

Human cells have surface protiens. Immune system doesnt attack own protiens - our cells in other body can trigger immune responce (blood)

63
Q

Non - self Antigens

A

Materials recognized by the immune system as not belonging to the organism - stimulate an immune responce

64
Q

Two types of specific immunity

A
  1. Humoral/ antibody meditated- B Cells

2. Cell mediated - T cells

65
Q

Where are b + t cells made and where do they mature?

A

Both produced in bone marrow. B cells mature in bones, T cells in thymus gland

66
Q

Antibodies

A

Specialised protien produced in responce to non-self antigen. Protien group called immunoglobulins (Ig)

67
Q

Antigen-Antibody complex

A

Specific antibody attaches to specific antigen. Should result in destruction/inactivation of antigen

68
Q

Humoral Responce

A

Billions of different types of B cells. Macrophage engulfs pathogen, present pathogen to T/B cell. Secretes Cytokines = activates B cells, B cells proliferates + differentaite into plasma cell makes protien, some clones of B cells become memory cells

69
Q

First exposure to Antigen

A

Primary responce. Takes time for B cells to differentiate into plasma cells and built up antibody levels

70
Q

Re-Exposure responce

A

Secondary respone. Memory cells respond much faster

71
Q

Antigens may…

A

Combine with bacterial/viral toxins/enzymes to inhibit them, bind to virus to prevent entry, coat bacteria for easier phagocytosis, Causes agglutination of foreign particles, make substances insoluable

72
Q

Cell mediated Immunity

A

Provides resistance to intracellular phase of bacterial/viral infections/ fungi + partasites.

73
Q

T Cells

A

One T cell is specific to one antigen. Can be stimulated by cytokines during humoral immunity

74
Q

T cell types + purpose

A

Enlarge and become one of three T cells -> Killer (Migrate to invaiding antigens + destory them)< Helper (Cause more lymphocytes to become sensitised + attract macrophages. Help both humoral and cell mediated)
Supressor (Inhgibit B + T cell activity)\

75
Q

Difference between T + B cells

A

B cells attack Invaiders outside cell, T cells attack infected Cells.

76
Q

Immunity

A

The resistance to infection by invaiding micro-organisms. Natural, artificial, passive, active.

77
Q

Natural immunity

A

Occurs without human intervention

78
Q

Artificial immunity

A

Results from giving people an antigen or antibody - human intervention

79
Q

Passive immunity

A

Person given antibodies produced elsewhere -> breastmilk. Usually short lived

80
Q

Active immunity

A

Exposure to the antigen causing the person to produce own antibodies - natural (chicken pox) artificial (vaccinations)

81
Q

Immunisation/Vaccination

A

The artificial introduction of antigens into the body to produce the appropriate antibodies + memory cells.

82
Q

Vaccination given as

A

Injections, orally, nostril sprays, skin patches.

83
Q

Small pox

A

Last recorded case in 1977 -> government promoted vaccination programs.

84
Q

Herd immunity

A

High proportion of population is immune to disease -low vacination rate = loss of herd immunity

85
Q

Outbreaks of previously low incidence diseases

A

Polio + whooping cough.

86
Q

Risks to vaccinations

A

Allergic reactions -> sometimes made in egg yolk, Introduction of cross species contamination, dangerous chemicals in manufacture.

87
Q

Ethical concerns on vaccine

A

How vaccines are manufactured, tested on animals and risk to peoples helth

88
Q

Hygiene Hypothesis

A

If a childs envrionment is too clean, lack of exposure to germs and doesnt give the immune system a chance to develop

89
Q

How does hygine hypothesis affect child health?

A

Less exposure to bacteria/viruses. No immune responce to pathogens, decrease immunity of infections, increased chance of being infected, oiver production of histamine -> allergies.

90
Q

Antibiotics

A

Used to fight infections of micro-organisms - bacteria

91
Q

How antibiotics work

A

Blocking translation during protien synthesis of bacteria

92
Q

Types of antibiotics

A

Bactericidal + Bacteristatic

93
Q

Bactericidal antibiotic

A

Kills bacteria by changing or damaging the structure of thir cell wall - allow contents to leak out

94
Q

Bacteriostatic

A

Stops bacteria from reproducing by blocking protien synthesis

95
Q

Resistance to antibiotics

A

Overuse of antibiotics in community has cuased evolution of generations of drug resistant bacteria

96
Q

Antivirals

A

Drug which inhibit the action of viral pathogens. Target specific protiens + disables them. boost bodys immune system to attack viruses