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3. Search for a Better Health Flashcards

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1
Q

Identify the four conditions which influence the growth of bacteria in food

A

Time: 1 –> 2 mill in 7hrs
Temperature: 5-60 degrees Celsius
Nutrients: poultry, meat, dairy, eggs
Water: moist conditions

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2
Q

Identify and describe the two primary situations in which food can become contaminated

A

During food prep: raw food residue is consumed

During food storage: raw food can leak onto other foods

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3
Q

Identify some techniques which can be used to prevent food poisoning

A

Wash hands thoroughly, cover cuts with bandages, washing equipment, storing food correctly.

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4
Q

Identify some personal hygiene practices which prevent the spread of disease

A

Wash hands, washing body, wearing clean clothes, disposing of sanitary items, brush teeth.

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5
Q

Describe the initial scientific belief for the presence of microbes

A

Due to the lack of technology, scientists could only make judgements based on what was observed by the naked eye. As a result, it was believed that organisms grew by ‘spontaneous generation’.

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6
Q

Identify the 5 discoveries Louis Pasteur contributed to science

A
  1. Importance of scientific method
  2. process of sterilisation and autoclaving
  3. weakened forms of microorganisms can be used for vaccination
  4. viruses through microscopes
  5. microorganisms exist in the air
  6. pasteurisation
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7
Q

Explain how Pasteur came to discover sterilisation and autoclaving

A

Through his work with pasteurisation, he found that by heating, he was able to kill all microbes.

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8
Q

Explain how Pasteur came to discover vaccination

A

In 1881, he conducted an experiment in which he isolated the anthrax bacteria and injected it into 25 healthy sheep, leaving another 25 as control. After some months, he gave all 50 the full bacteria. All the control sheep died.
In 1882, he obtained a vaccine for rabies by obtaining a form of the virus through dried tissues and injected it into a 9yo boy.

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9
Q

Explain how Pasteur came to discover that microorganisms reside in the air

A

Through Pasteur’s experiment using two flasks, he proved that organisms reside in the air, and do not spontaneously generate in food. He thus developed that ‘germ theory of disease’; that all microbes cause disease and all microorganisms come from pre-existing microorganisms.

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10
Q

Explain how Pasteur came to discover pasteurisation

A

Pasteur was asked by the French government to examine why their why began to taste sour. Through observing sour wine and milk, he found the same microbes in them. He found that by heating the liquids between 55-60 degrees Celsius, the ‘bad’ microbes were killed.

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11
Q

Identify the three discoveries Koch made

A
  1. Agar plate technique
  2. determined that each disease is caused by a specific organism
  3. Koch’s postulate
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12
Q

Explain how Koch came to discover his postulates

A

Through studying anthrax, he found that a specific bacteria was present in the blood of infected animal, but not uninfected. He thus isolated the bacteria from the blood, made descriptions, injected that bacteria into a healthy animal and found that the animal also developed anthrax. He then collected samples from the secondary animals and found the same bacteria in their blood.

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13
Q

Identify Koch’s Postulates

A
  1. the same microorganisms must be present in every diseased host
  2. the microorganism must be isolated, cultured in the lab, accurately described and recorded.
  3. when a sample of the pure culture is inoculated into a healthy host, the host must develop the same symptoms as the original host.
  4. the microorganism must be able to be isolated from the second host, cultured and identifies as the same species.
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14
Q

Describe the characteristics of a prion and a disease which is caused by a prion

A

Cell fragment, consisting onto of abnormal proteins present in brain or nerve cells. It causes normal proteins to produce the infectious version (e.g., Mad Cow Disease)

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15
Q

Describe the characteristics of a virus and a disease which is caused by a virus

A

Core of nucleic acid, with a protein coat. It attaches to cell membranes and viral DNA or RNA causes cell to make viral protein and viral DNA/RNA, ultimately killing the cell (eg. influenza)

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16
Q

Describe the characteristics of bacteria and a disease which is caused by bacteria

A

Procaryotic. Absorbs nutrients from cells and releases enzymes to destroy cells. (e.g. Anthrax)

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17
Q

Describe the characteristics of protozoans and a disease which is caused by protozoa

A

Unicellular, eukaryotic, no cell wall. Different types based on mode of transport: flagellates, ciliates, amoeba, sporozoa (e.g. Malaria)

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18
Q

Describe the characteristics of fungi and a disease which is caused by fungi

A

Eucarytic organisms with a cell wall. Absorbs nutrients from dead cells, yet becomes infectious when spreads through living tissues. (eg. Athlete’s Foot)

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19
Q

Describe the characteristics of macro parasites and a disease which is caused by macro parasites

A

Multicellular, eucaryotic organisms. Can be the cause of a disease or a vector. There are endoparasites and ectoparasites (eg. Roundworm, lice).

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20
Q

Define: naturally induced active acquired immunity

A

Body undergoes immune response and suffers symptoms

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21
Q

Define: artificially induced active acquired immunity

A

Body produces immunity without suffering symptoms

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22
Q

Define and describe the ‘primary immune response’

A

The first response the body mounts against a pathogen. This response takes time to build as specific B and T cells are activated and cloned. After the body defeats the pathogen, memory B and T cells remain.

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23
Q

Define and describe the ‘secondary immune response’

A

The subsequent times a pathogen enters the body, the memory B and T cells are able to active the production and cloning of B and T cells at a faster rate. It is much faster, producing greater quantity of antibodies and lasts for a long period of time.

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24
Q

Describe how immunisation interacts with the immune system and what it involves

A

Immunisation stimulates the body’s immune response, without the body undergoing the symptoms of the disease. It involves vaccination, which is a culture of the pathogen which induced a specific disease, either attenuated, dead or as a toxoid.

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25
Q

Why do some vaccinations require boosters?

A

The number of memory cells decrease over time. Further, the more that the body is exposed to a pathogen, the better and faster it is able to respond to it.

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26
Q

Define: passive acquired immunity

A

The introduction of antibodies into the body from another organism.

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27
Q

Identify some of the problem with vaccinations

A
  1. side effects
  2. not long-term (require boosters)
  3. as some of the most fatal diseases (such as smallpox) are not longer prevalent in society, individuals neglect immunisation.
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28
Q

Define: tissue rejection

A

When a patient receives a donated organ, the immune system will identify the antigens as ‘non-self’ and will thus mount a response to destroy it.

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29
Q

Explain why tissue rejection occurs and how doctors combat it.

A

Tissue rejection occurs due to the T-lymphocytes, which identify the ‘non-self’ antigens on the surface of the donated cells. As a result, patients must take immunosuppressive drugs in order to suppress the immune system, leaving the patient susceptible to infection. Drugs such as cyclosporin A suppress T cells but not B cells, enabling the continued production of antibodies.

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30
Q

Describe the contributions made by McFarlane Burnett

A

McFarlane-Burnett developed a method for culturing viruses by injecting viruses into the membrane of chick egg. This allowed him to prove the ineffectiveness of attenuated influenza.
He further produced that ‘clonal theory of selection’ and he postulated that the immune system could distinguish between ‘self’ and ‘non-self’ cells, allowing the immune system to mount a response against foreign cells only. He also suggested that this could be learned.

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31
Q

Who supported McFarlane Burnett’s clonal theory go selection and what experiment did he conduct?

A

Dr Peter Medawar conducted an experiment in which he introduced foreign tissue to a mouse foetus. When the mouse had grown, he reintroduced the forge in tissue, which the mouse accepted.

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32
Q

Define ‘Health’ and ‘Disease’ and describe why these terms are difficult to define

A

Health: a state of physical, mental and social wellbeing. When an organism is functioning effectively with its environment
Disease: part of the body does not function normally. It impairs, or has the potential to impair, the functioning of the organism.
These terms are challenging to define as an individual’s understanding of ‘healthy’ and ‘functioning normally’ varies.

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33
Q

Outline how the function of genes contributes to the maintenance of health

A

Maintenance of health relies on information stored in DNA, which codes for proteins that are responsible for healthy cell functioning. Mitosis also relies on these proteins for cellular repair. Such genes include:

  • DNA repair genes: codes for proteins that stop the cell cycle to allow other genes to repair DNA. If they mutate, damaged DNA will undergo mitosis
  • Proto-oncogenes: proteins that stimulate cell growth and mitosis. If they mutate, can lead to oncogenes which cause uncontrolled production of cells
  • Tumour supressor genes: proteins that slow down cell growth, mitosis and induce cell death.
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34
Q

Outline how cell differentiation and specialisation assists the body’s defence against disease

A

Cell differentiations produces specialised cells which can assists they body’s defence against disease:

  • Lymphocytes: 3rd line of defence
  • Phagocytes: WBC which engulf pathogens (2nd LOD)
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35
Q

Define: gene expression

A

Refers to when genes are switched ‘on’ and ‘off’. It is the genes that are switched ‘on’ which are used to produce polypeptide chains to control of functioning of cells. Correct gene expression is therefore necessary for maintenance of health.

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36
Q

Provide an example of a case in which incorrect gene expression leads to disease

A

One type of great cancer is due to the mutation on the BRCA1 gene, which is a tumour suppressor gene that codes for the proteins that repair PTEN gene. PTEN is also a tumour suppressor gene that limits cell division and encourages cell death. Mutations to the BRCA1 gene mean that the repair proteins are not being produced, meaning that damages to the PTEN gene cannot be repaired and is thus not expressed correctly. This results in a lack of control of the cell cycle, resulting in excessive growth of undifferentiated, immature cells, leading to cancer.

37
Q

Define; infectious disease

A

disease causes by a microscopic or macroscopic organisms, referred to as a ‘pathogen’.

38
Q

Define: non-infectious disease

A

diseases caused by a factor other than a pathogen, included dietary, genetic, environmental

39
Q

Identify the conditions under which an organisms is considered a pathogen

A

The invasion of a pathogen into the body is called an ‘infection’. Factors which influence the whether an organisms is a pathogen includes:

  • Pathogenicity: pathogen must be pathogenic to host
  • Entry: pathogen must be able to enter host
  • Exit: pathogen must be able to exit host to infect others
  • Transmission: pathogens must be able to move between hosts
  • Pathogen must be able to survive host’s defence mechanisms
40
Q

Identify the characteristics of bacterial and fungal colonies

A

Bacterial: shiny, moist, small, brightly coloured
Fungal: large, matte, fibrous, dull colours

41
Q

Identify the characteristics used to describe a colony

A 
Surface
Margin
Colour
Elevation
Opacity
Size
Colonial form
42
Q

Identify 2 risks when culturing microbes

A
  1. Contact with microbes:
    Prevention: spray bench with 70% ethanol before and after, wash hands before and after, seal agar plates and never reopen, autoclave equipment
  2. Handling 70% ethanol:
    Prevention: spray away from others, avoid naked flame, wear safety goggles.
43
Q

Identify processes used to treat drinking water

A

‘Sydney Water’ is responsible for the treatment of water in Sydney. They monitor the water to ensure that pathogens (Giardia), particulates and metals and removed from the water, to ensure the health of the public. Processes include:

  • Microbial indicators: Coliform bacteria are used as indicators to test for the presence of microorganisms
  • All water is filtered and undergoes flocculation
  • Chlorination: used to disinfect water by introducing small amounts of chlorine gas into the water to killing microorganisms
  • Chloramination: small amounts of ammonia is added to produce chloramines which proceed longer lasting means of disinfection.
44
Q

Define: antibiotics and provide and example

A

Chemical compounds used to kill or inhibit growth of infectious bacteria. Naturally produced by bacteria and fungi in a defence against other bacteria. All antibiotics have selective toxicity: they are more toxic to the pathogen than the host. Bacteria are either bactericidal (kill) or bacteriostatic (stop bacteria growth).
Penicillin are bactericidal by preventing the formation of the cell wall. They are effective against staphylococci and meningococci.

45
Q

Outline the 7 historical events which have contributed to our understanding of malaria

A

17th century: discovery of quinine to reduce malarial fevers
1880: Laveran discovered protozoan parasite in blood of all malarial victims
1897: Ronald Ross: demonstrates the role of the mosquito as he found cysts in the stomach walls of mosquitoes which contained parasite
1939: Malaria control advanced due to introduction of DDT
Late 1950s: WHO introduced mosquito nets
1970s: Anti-malerial drugs
1981/2015: search for a vaccine.

46
Q

Summarise the cause, transmission, host response, symptoms, treatment, prevention and control of malaria

A

Cause: protozoan, Plasmodium
Transmission: from the bite of female Anopheles mosquito. Sporozoites travel to liver to undergo asexual reproduction. Merozoites burst from liver weeks after 2-4 weeks and invade erythrocytes. Burst from RBCs and invade other RBC or liver cells until they develop into gametocytes in RBCs. If ingested by another mosquito, will form male and female gametes in gut, fertilise and migrate to salivary glands.
Host Response: Plasmodium is isolated from immune system in liver cells, yet can develop an immune response after. Plasmodium changes antigens even week.
Major Symptoms: When RBCs burst, toxic waste products are also released resulting in shivering, high fevers, headaches, sweating and anaemia.
Treatment: antimalarial drugs
Prevention: antimalarial drugs, mosquito nets, new vaccines, protective clothing.
Control: focussed on destroying adult mosquitoes and draining stagnant water.

47
Q

Discuss the problems with antibiotic resistance and how bacteria can develop resistance

A

Genes which carry resistance can be transmitted through plasmids. Bacterium conjugate and duplicates of resistant plasmids are transferred. Multiples resistant genes can be formed into one plasmid.
Resistance is the resulting of inappropriate use of antibiotics, not taking antibiotics for the full course.
Problems: effects of diseases are more severe, take longer to cure, intensive antibiotics are more toxic and expensive, limited treatments for MRSA
Strategies: take antibiotics for prescribed timeframe, do not take antibiotics for viral infections.

48
Q

Define: Natural Resistance

A

resistance present at birth, non-specific resistance

49
Q

Define: Acquired Resistance

A

obtained during one’s lifetime and involves the production of B and T lymphocytes which act against a specific pathogen (immune response).

50
Q

Describe how skin inhibits the entry of pathogens

A
  1. Protein keratin hardens skin to acts as a physical barrier.
  2. Antibacterial and anti-fungal organic acids (sweat and sebaceous glands) give skin an acidic pH, discouraging growth of pathogens
  3. Lack of moisture inhibits growth
51
Q

Describe how mucous membranes inhibit the entry of pathogens

A

fluid that traps pathogens. Lines the walls of respiratory, urogenital and respiratory

52
Q

Describe how cilia inhibit the entry of pathogens

A

Small hairs attached to epidermal layer which beat to move mucous and pathogens into the throat. Nasal pathogens have hairs to filter air.

53
Q

Describe how chemical barriers inhibit the entry of pathogens

A

Mucous lines respiratory tracy, skin surface is slightly acidic, HCl in stomach, bile is slightly acidic, vaginal opening is slightly acidic

54
Q

Describe how other bodily recreation inhibit the growth of pathogens

A

Tears contains enzymes, saliva contains enzymes, sweat is acidic and clears sweat glands, urine is sterile and slightly acidic

55
Q

Define: antigen

A

Proteins markers (molecules) on the surface of foreign cells which the body recognises as ‘non-self’ and thus triggers the immune response.

56
Q

Explain why organ transplants trigger the immune response

A

The new organ introduced into the body carry protein markers on their cells (antigens) which are different to the markers of ‘self’ cells. As a result, the immune system recognises the cells as foreign and mounts a response against it. To reduce this, tissue type of the donor is matched to the recipient so that there is a high number of matching molecules. This means that there are fewer antigens, resulting in a less violent response. Immunosuppressent drugs are also taken.

57
Q

Describe how phagocytosis contributes to the body’s defence against pathogens

A

Process in which phagocytes (specialise leukocytes) change their shape to surround a pathogen. Enzymes are released to kill pathogens and antigens are expressed on the surface. Two types:

  1. Neutrophils: respond to chemicals signals, after engulfing - tend to self-destruct.
  2. Monocytes: circulate in the blood and them migrate to tissues to develop into macrophages. Fixed macrophages reside in tissues and free macrophages circle in blood. Long-lived and extend pseudopodia to attach to pathogen’s surface.
58
Q

Describe how immunological surveillance contributes to the body’s defence against pathogens

A

Constant monitoring of normal tissues by natural killer (NK) cells. They destroy abnormal somatic cells (cells with a virus or cancers) by attaching to cell membrane, causing it to lyse.

59
Q

Describe how the inflammatory response contributes to the body’s defence against pathogens

A

Damage to tissues triggers inflammatory response, consisting of the release of chemical signals, leading to dilation of blood vessels and increased permeability. This increases blood flow and allows macrophages to move out of blood vessel and engulf pathogens. Blood clotting seals affected region off as site it warm, painful and red.

60
Q

Describe how the lymphatic system contributes to the body’s defence against pathogens

A

As blood circulates in the blood, plasma moves out of capillaries and becomes intersitial fluid. Fluid them moves to lymphatic system. Lymph vessels for a one-way drainage system which leads back to a region near the heart where cleaned fluid in drained back into the blood. Muscles and valves ensure the one-way movement of lymph fluid. Infected cells are taken to lymph nodes and glands.

61
Q

Describe how cell death to seal off a pathogen contributes to the body’s defence against pathogens

A

Infected cells are surrounded by a wall of dead cells to prevent the infection from spreading. The infected cells inside the cyst will die and be destroyed by macrophages.

62
Q

Explain how Candidiasis is a result of an imbalance in the body’s microflora

A

Along the surface of skin, genital trace and gut, benefits microorganisms (microflora) are present to prevent the growth of pathogens. When the natural balance of microflora in upset, the population of the fungus, Candida can increase, causing the disease. When the number of the fungus is too low, pathogen kill body cells, allowing fungus to return. If fungus population is too high, disease results.
Taking antibiotics, suppression of immune system, illness and pregnancy influence the population of Candida

63
Q

Describe the production and role of T lymphocytes

A

Produced in the bone marrow and mature in the thymus (thoracic cavity). They are released into the blood, spleen, tonsils and lymph nodes.
Cell-Mediated Immunity
Each T cell has a specific ‘surface receptor protein’ that recognises a specific antigen. When activated, produce many killer T cells which travel to site of infection and release chemicals to destroy infected cell. Attack against bacteria and viruses INSIDE cells, pathogens and foreign tissue.

64
Q

Describe the production and role of B lymphocytes

A

Produced and mature in the bone marrow. Released into the blood, spleen, tonsils and lymph nodes.
Humoral / Antibody-Mediated Immunity
Each mature B cell produced a different antibody that only responds to a specific antigen. When activated, it clones itself and forms plasma cells which release antibodies.
Antibodies move to the site of infection and combine with antigen to form antigen-antibody complex.
Defend against bacteria and viruses OUTSIDE cells and toxins produced by bacteria.

65
Q

Describe the production and role of antibodies

A

Proteins, called immunoglobulins. When B cells are activated, they clone and form plasma cells which produce antibodies. Their antigen binding sites match the shape of the antigen. An antigen is destroyed by immobilising it, blocking and neutralising active binding site of antigen and causing antigen-antibody complexes to clump together, which is easier to eliminate by phagocytosis.

66
Q

Describe the interactions between B and T lymphocytes

A

When an antigen-presenting macrophage enters a lymph node or gland and presents itself to the specific helper-T cell that has the specific surface receptor protein, the T cell is activated.
Helper T cells are also activated by B cells. When a B cells encounters an antigen that matches its surface antibodies, it binds to the antigen (antigen-antibody complex). The B cells then presents to the specific helper T cell.
Once activated, the helper T cells excrete chemicals (cytokines) such as interleukin-2 which activates the production of B cells and cytotoxic T cells.

67
Q

Summarise Antibody-Mediated Immunity

A

Occur when B lymphocytes are activated by produce antibodies, which defend the body against pathogens outside of cells. When a helper T cell is activated, it recreates interleukin-2 to activate the cloning on B cells and their formation into plasma cells. Plasma cells then excrete 2000 antibodies per second for 4-5 days. Antibodies binds to their specific antigen, forming antigen-antibody complexes. They destroy of antigens by:

  • blocking tis activity
  • activating complement proteins, causing pathogen to clump together, enhancing phagocytosis.
  • Inflammation is increased to pump more phagocytes into the area.
68
Q

Summarise Cell-Mediated immunity

A

Occurs when T cells destroy the body cells of a host that have been invaded by a pathogen. They also defend against cancers (carrying distinctive molecules) and transplanted tissues.
Helper T cell stimulate the production of Cytotoxic T cells. When they encounter an infected cells presenting antigens, they destroy it by:
- releasing perforin (protein) to rupture cell membrane, depriving the pathogen of a place to reproduce and allowing antibodies to attack it.
- poisoning it
- activating genes in the cell to self-destruct.
- release chemicals to stimulate phagocytosis, increase inflammation and protect neighbouring cells
Supressor T cells ‘turn off’ the immune response.

69
Q

Explain Immunological Memory

A

Initial exposure to a pathogen (primary response)produces memory B and T cells which are poised to proliferate rapidly if the body encounters the same pathogen again.
Ability to memory cells to recognise antigens is referred to as ‘immunological memory’

70
Q

Identify and describe the four types of T lymphocytes

A

Helper T cells: have receptor proteins which recognise only one antigen. When activated (either by macrophages or B cells) release the cytokine chemical, interleukin-2, to stimulate the production of other B and T cells.
Cytotoxic T cells: bind with infected cells and release chemicals that destroy the infected cell.
Memory T cells: produced at the same time as cytotoxic T cells and remain in the body to stimulate a faster secondary response
Supressor T cells: stop the immune response when the infection has been defeated.

71
Q

Define: Clonal Theory of Selection’

A

All the B and T cells for all possible antigens are already present in very small concentrations in the immune system. When an antigen is present in the body, the specific B and T cells that are specific for the antigen is activated, cloned and the antigen is destroyed.

72
Q

Explain the effectiveness of vaccines in treating smallpox

A

Viral disease resulting in high fever, rash and pimples.
Before: 300 million deaths in the 20th century. Pandemic.
Vaccine Produced: in 1796 Edward Jenner produced vaccine, yet not widely used. 1967 WHO introduced mass immunisation. Mass immunisation targeted people who had missed vaccines and included surveillance groups.
After: eliminated disease from world population.
Evaluation: smallpox has been eradicated, therefore successful

73
Q

Evaluate the effectiveness of vaccines in treating diphtheria

A

Disease caused by toxins released by bacteria. Attach mucous membranes.
Before: in 1980, 100000 thousands cases worldwide. Pandemic.
Vaccine produced: 1930-1940, Australia has a rapid decrease in disease due to vaccination. In 1974, WHO launched Expanded Program and immunisation (EPI). By 1990, 80% children were immunised.
After: spread rate has decreased.
Evaluation: very effective as a drop in global incidence.

74
Q

Evaluate the effectiveness of vaccines in treating poliomyelitis

A

Viral disease that attacks the nervous system and causes permanent paralysis.
Before: Pandemic in 125 countries
Vaccine produced: 1955, Jonas Stalk produced vaccine using inactivated virus (problems as people contracted disease from vaccine) Albert Sabin produced attenuated virus.
After: 60-70% reduction in cases. Rare in industrialised countries.
Evaluation: effective in developed countries.

75
Q

Define: Epidemiology

A

The study of the incidence and distribution is disease in large populations. Focusses on the effects of age, sex, nationality, and socioeconomic factors.

76
Q

Identify factors in which epidemics are likely to occur

A
  • population have a lowered state of resistance
  • virulent strain of pathogen
  • pathogen has an easy means of transmission
77
Q

Identify and describe Epidemiological studies in relation to lung caner

A
  1. Descriptive Studies: collect information about the pattern of disease, including frequency, demographics of population and location (general information). When determining the effects of lung cancer, studies collects information about the sex, age, smoking habits, diet and drinking habits of smokers and non-smokers.
  2. Analytical Studies: collect more specific data which is statistically analysed. Provides information about modality, mortality, incidence (new cases at once) and prevalence (of people affected at once). Two types of studies: 1. Case-Control: compared people with lung cancer to people without lung cancer. Discovered that people with cancer smoked more. 2. Cohort Studies: long-term studies on two similar groups with only one difference (IND). Doctors were studies for over 10 years and it was found that the doctors that smoked more had cancer.
  3. Intervention Studies: studies the effectiveness of treatment and public health campaigns. Studied the effectiveness of ‘Quit’ campaigns.
78
Q

identify the factors the make an epidemiological study effective

A
  • . be conducted over a long period of time
  • large sample sizes
  • collect relevant data
  • use controls
  • statistically analyse morbidity, mortality, incidence and prevalence
  • identify causes
  • develop management plan
  • evaluate effectiveness
79
Q

Identify an inherited disease and identify its cause

A

The Down Syndrome: cause by an error during reduction division as individuals have an additional copy of chromosome 21. Caused by:
non-disjunction of chromosome 21: does not split during meiosis
translocation of chromosome 21: part of chromosome breaks off and fuses with another chromosome

80
Q

Identify a nutritional disease and identify its cause

A

Scurvy: caused by low level of vitamin C

81
Q

Identify an environmental disease and identify its cause

A

Hypothermia: caused by exposure to extreme cold

82
Q

Define: cancer

A

Uncontrolled multiplication of immature, undifferentiated cells.

83
Q

Describe the cause and effect relationship between smoking and lung cancer

A

Epidemiologists in the US notices that whilst the occurrence of lung cancer was rare before the 20th century, its occurrence increased dramatically following the 1930s. The American Cancer society conducted research to compare death among smokers and non-smokers, finding that smokers had a higher mortality rate. Further studies showed that chemical contained in cigarettes are carcinogenic.
Thus, smokers are more likely to develop cancer, emphysema, stroke, giving birth prematurely.
Note: there is a 20 year delay between smoking and developing cancer.

84
Q

Describe the occurrence, symptoms, cause and treatment of lung cancer

A
  • Occurrence: 5th most common cancer in Australia. 1 in 33 Australians will develop lung cancer by 75. In the last 10 years, incidence of males has decreased, whilst females have increased.
  • Symptoms: cough, shortness of breath, lung infections, weight loss
  • Cause: smoking and exposure to industrial chemicals (asbestos)
  • Treatment: surgery, radiotherapy, chemotherapy, laser treatment.
85
Q

Define: pathogen

A

parasitic organism that causes disease

86
Q

Define: infection

A

the invasion of a pathogen into the body

87
Q

Define: immunity

A

the ability to resist or overcome invasion by a pathogen

88
Q

Describe how fever contributes to the body’s defence against pathogens

A

The maintenance of a body temperature above 37.2 degrees as a response to infection. It can be beneficial to inhibit the growth of pathogens, speed up phagocytosis and speed up the repair of tissues.

HSC Biology (4 decks)

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