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Year 12 Human Biology > Immune System > Flashcards

Immune System Flashcards

(96 cards)

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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
Skin - defence
an impervious barrier. Large amount of bacteria on skin - difficult for new pathogenic establishments
26
Urethra - defence
Urine flow prevents bacterial growth
27
Anus - defence
Mucous membrane traps microorganisms
28
Mucous membranes
FOund in digestive, urinary, respiratory and urogenital tracts - line body cavities and inhibits entry of micro organisms
29
Hairs - defence
Trap micro organisms
30
Cilia
Found in respiratory tract. Tiny microscopic hair like progections. Moves muccous towards throat.
31
Acids
Found in stomach, vagina and sweat. kills microorganisms ingested w/ food or in mucous.
32
Lysozyme
Enzyme that kills bacteria. Lysozyme -> enzyme created byy lysosomes. Found in tears, saliva, sweat, nasal secretions, tissue fluid.
33
Cerumen
Found in outer ear, slightly acidic and contains lysozymes.
34
FLushing action
Occurs in urine flowing through urethra, tears, sweat and saliva. - cleansing action
35
Protective reflexes
Sneezing, coughing, vomiting, diarrhea
36
Sneezing
Irritation of walls of nasal cavity - forceful expulsion of air from lungs
37
Coughing
Irritation of respiratory tract - bronchi/bronchioles. Air forced from lungs.
38
Vomiting
Psychological - excessive stretching of stomach - muscles of abdomen and diaphragm contract. stomach contents expelled.
39
Diarrhea
Irritation of small/large intestines by pathogens. Increased peristalsis to remove irritant.
40
First line defence successfulness
Not always successful - burns and cuts reduce effectiveness. If 1st fails, move onto third and second defence
41
Second line of defence
Phagocytic leukocytes, antimicrobial protiens, inflammatory responce, fever.
42
Non-specific defence
Consists of lymph nodes, vessles, lymphoid tissues and different leucocytes.
43
Lymph vessel structure
Like veins - squeezing action and valves
44
Lymphatic system
Drains intercellular fluid back to the heart and circulatory system.
45
Leucocytes - WBC
Different types - all leave the blood capillaries and migrate to place of infection/injury
46
Types of leucocytes
Macrophages + Lymphocytes (B+T cells)
47
2nd line of defence - Phagocytosis
Any WBC that is capable of engulfing and digesting micro-organisms and cell debis = phagocyte. eg macrophages
48
Macrophages
Involved in specific + non specific defence. - carry out phagocytosis, release substances to destory pathogens
49
Lymphocytes - B+ T cells
Involved in specific and non specific defence. Produced in bone marrow and some lymphoid tissue - curculate through tissue, blood + lymph
50
Inflammation
Responce to tissue damage. Reduce spread, destroy and stop further entry of pathogens.
51
Inflammatory responce - steps
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
Fever
Increase body temperature
53
Normal body temperature
Aprox 37.5 degrees celcius
54
Increased body temperature
Increases heart rate and blood flow. therefore speed of lymphocytes reaching area of infection. 2. Non optimum condition of pathogen - death 3. Increase production of T cells 4. Increase metabolic rate - healing.
55
If temperature is to high
Enzymes denature. Harmful if temperature gets to 44-45 degrees.
56
When pathogen enters the body
Releases a chemical Interleukin 1 causes the hypothalamus to increase body temperature. Macrophages engullf pathogen
57
Conditions at normal body temperature when fever starts
Feel cold, responds by shivering, piloerection (goose bumps) and vasoconstriction of the blood vessles (pale) to warm up
58
Fever broken
Infection is over - no more pathogens and hypothalamus resets to 37.5. Temperature is to hot and Vasodilation occurs and sweatingS increases.
59
Specific defences
Recognizes foreign molecules and acts to inactivate/destroy them
60
3 important aspects - Specific defences
Acts against specific pathogens, not restricted to inital infection site, recognizes and launches stronger test on previous encountered pathogen
61
Antigen
Any substance capable of causing a specific immune responce - protien, carbohydrates, virus, pollen etc
62
Self - Antigens
Human cells have surface protiens. Immune system doesnt attack own protiens - our cells in other body can trigger immune responce (blood)
63
Non - self Antigens
Materials recognized by the immune system as not belonging to the organism - stimulate an immune responce
64
Two types of specific immunity
1. Humoral/ antibody meditated- B Cells | 2. Cell mediated - T cells
65
Where are b + t cells made and where do they mature?
Both produced in bone marrow. B cells mature in bones, T cells in thymus gland
66
Antibodies
Specialised protien produced in responce to non-self antigen. Protien group called immunoglobulins (Ig)
67
Antigen-Antibody complex
Specific antibody attaches to specific antigen. Should result in destruction/inactivation of antigen
68
Humoral Responce
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
First exposure to Antigen
Primary responce. Takes time for B cells to differentiate into plasma cells and built up antibody levels
70
Re-Exposure responce
Secondary respone. Memory cells respond much faster
71
Antigens may...
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
Cell mediated Immunity
Provides resistance to intracellular phase of bacterial/viral infections/ fungi + partasites.
73
T Cells
One T cell is specific to one antigen. Can be stimulated by cytokines during humoral immunity
74
T cell types + purpose
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
Difference between T + B cells
B cells attack Invaiders outside cell, T cells attack infected Cells.
76
Immunity
The resistance to infection by invaiding micro-organisms. Natural, artificial, passive, active.
77
Natural immunity
Occurs without human intervention
78
Artificial immunity
Results from giving people an antigen or antibody - human intervention
79
Passive immunity
Person given antibodies produced elsewhere -> breastmilk. Usually short lived
80
Active immunity
Exposure to the antigen causing the person to produce own antibodies - natural (chicken pox) artificial (vaccinations)
81
Immunisation/Vaccination
The artificial introduction of antigens into the body to produce the appropriate antibodies + memory cells.
82
Vaccination given as
Injections, orally, nostril sprays, skin patches.
83
Small pox
Last recorded case in 1977 -> government promoted vaccination programs.
84
Herd immunity
High proportion of population is immune to disease -low vacination rate = loss of herd immunity
85
Outbreaks of previously low incidence diseases
Polio + whooping cough.
86
Risks to vaccinations
Allergic reactions -> sometimes made in egg yolk, Introduction of cross species contamination, dangerous chemicals in manufacture.
87
Ethical concerns on vaccine
How vaccines are manufactured, tested on animals and risk to peoples helth
88
Hygiene Hypothesis
If a childs envrionment is too clean, lack of exposure to germs and doesnt give the immune system a chance to develop
89
How does hygine hypothesis affect child health?
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
Antibiotics
Used to fight infections of micro-organisms - bacteria
91
How antibiotics work
Blocking translation during protien synthesis of bacteria
92
Types of antibiotics
Bactericidal + Bacteristatic
93
Bactericidal antibiotic
Kills bacteria by changing or damaging the structure of thir cell wall - allow contents to leak out
94
Bacteriostatic
Stops bacteria from reproducing by blocking protien synthesis
95
Resistance to antibiotics
Overuse of antibiotics in community has cuased evolution of generations of drug resistant bacteria
96
Antivirals
Drug which inhibit the action of viral pathogens. Target specific protiens + disables them. boost bodys immune system to attack viruses

Year 12 Human Biology (7 decks)

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