The Search For Better Health Flashcards
Discuss the difficulties of defining the terms “health” and “disease”
Health; “State of physical, social and mental wellbeing, not just absence of disease” WHO
Hard to achieve all 3 areas at once, different opinions about what is healthy
Disease: “Condition adversely affecting normal functioning of any part of living thing”
Broad, conditions not normally classed as disease (pregnancy, broken arm)
Use available evidence to analyse the links between gene expression and maintenance and repair of body systems
Gene expression; Cell ‘switched on’ and DNA code converted to polypeptides controlling structure and function of cell
Expressed as should be→ cell functions normally, tissues maintained and repaired
Polypeptides make up proteins; some responsible for mitosis and cell cycle, or replace damaged cells
Effective gene expression needed for ongoing maintenance/repair of tissue→ if altered mutations and cells can’t function
Tumour suppressor gene→ limits cell division, encourages cell death of too many cells
BRCA1 gene→ Codes for proteins repairing PTEN gene,
PTEN gene→ limits cell divisions, encourages cell death; regulates cell cycle, prevents excessive cell production
Outline how the function of genes, mitosis, cell differentiation and specialisation assist in the maintenance of health
Cell differentiation→ Cells mature, take on different structural features to suit for specific function
Cell specialisation→ Specific genes ‘switched on’ → perform particular body function
Enable cells to work together to carry out coordinated complex functions to maintain, repair tissue
Genes control production of polypeptides (make up cell proteins)→ responsible for cell growth, repair
Gene malfunction→ cells can’t function, onset of disease
Mitosis; cell division→ growth, repair damaged tissues, worn out cells→ can cause mutations; uncontrolled production of cells, prevents cell death
Mutations→ tumour suppression genes halt protein production
Disruption of cell cycle; uncontrolled cell replication→ cells don’t differentiate; forms tumours
OVER 3000 YEARS AGO THE CHINESE AND HEBREWS WERE ADVOCATING CLEANLINESS IN FOOD, WATER AND PERSONAL HYGIENE
People of Mesopotamia
Drains→ carry away waste
Aware of insects carrying disease, isolated the sick
Egyptians
Performed surgery and had over 700 drugs
Specific rules for cleanliness→ house cleaning, frequent bathing, pure water
Chinese
Personal hygiene and classified diseases
Immunity→ if exposed to tissue of person with smallpox→ gain protection against more infection
Hebrews
Personal hygiene by washing and keeping clean
Water supplies kept clean, free of wastes, dead animals and people
Isolated sick and burnt used bandages
Distinguish between infectious and noninfectious diseases
Infectious; disease caused by organism, infectious agent→ Ebola, Zika
Non-infectious; not caused by pathogen, can’t be passed on→ Down Syndrome, lung cancer
Identify data sources, plan and choose equipment or resources to perform a first hand investigation to identify microbes in food or in water
Petri dish; innoculate bacterial colonies (e-coli) wipe in cultivated agar plate, attach antibiotic; seal
Heat, observe next day how much bacteria grown→ antibiotic with least bacteria (effective)
Explain why cleanliness in food, water and personal hygiene assist in control of diseases
HYGIENE
Hygiene→ decreases spread and growth of pathogens→ controls spread of disease
PERSONAL
Keep body and openings clean→ reduce risk of pathogens entering
Wash hands with soap before eating, after using toilet→ prevents spread of disease
Body, hair, teeth regularly cleaned→ prevent buildup of bacteria
Cough or sneeze into handkerchief→ prevents airborne droplets spreading
COMMUNITY
Sewerage, garbage disposal→ reduces increase of pathogens
Sterilisation, disinfection of equipment in hospitals, dentists→ reduces pathogen spread
City planning– reduces overcrowding→ reduce transmission of disease through pop
Explain why cleanliness in food, water and personal hygiene assist in control of diseases
CLEANLINESS IN FOOD
Pathogens transferred from person to person, or environment to person via food
Increased incidence of foodborne disease→ due to eating out on regular basis, consume takeaway
Guidelines; hair tied back, cuts covered, hands washed, utensils washed, raw veg washed, meat cooked thoroughly, food covered before stored
Explain why cleanliness in food, water and personal hygiene assist in control of diseases
CLEANLINESS IN WATER
Domestic water→ comply with strict standards and guidelines
Water contaminated with faces→ could contain unsafe pathogens
Treatment→ destroys pathogens and multiplication→ reduce transmission
Gather, process and analyse info from secondary sources to describe ways in which drinking water can be treated and use available evidence to explain how these methods reduce the risk of infection from pathogens
Water treated before distribution→ ensure no health risk
Coagulation/flocculation/sedimentation/filtration→ remove matter harbouring pathogens, disinfect
Testing to ensure water meets guidelines
Water should be clear→ virtually colour free
Tested; bacteria associated with faecal contamination→ killed by chlorine
Cryptosporidium, Giardia→ may infect animals in intestines; in water through faces or animal carcass
Chlorine→ added to water to kill pathogens
Fluorine→ added to tap water to help dental health
Identify the conditions under which an organisms is described as a pathogen
Any organism or infectious agent living in another organism and causing disease
Microorganisms can become one if not in normal location (E.g. good bacteria on skin if enters blood)
Methods of infectious transmission
- Person to person; (blood→ HIV, Ebola)
- Environment to person (common cold)
- Vector; person to person via organism (Zika)
DURING THE SECOND HALF OF THE NINETEENTH CENTURY, THE WORK OF PASTEUR AND KOCH AND OTHER SCIENTISTS STIMULATED THE SEARCH FOR MICROBES AS CAUSES OF DISEASE
19th century→ revolution in microbiology (pasteur and Koch) → previously spontaneous generation
P disproved theory; germ theory→ all germs cause disease, microorganisms come from pre- existing
Koch→ all disease caused by specific microorganism
Describe the contribution of Pasteur and Koch to our understanding of infectious diseases
PASTEUR
Discovered microorganisms were cause of beer, wine spoilage→ Heat them to kill (pasteurisation)
Discovered rotting food due to living organism, (refuted spontaneous generation) proposed germ theory of disease
Investigated cause of anthrax and developed successful vaccine→ also vaccine or rabies, cholera in chickens
Swan necked flask experiment
- Drawn out necked flask→ meat inside and air drawn in→ microorganisms from air trapped in curved neck
- No growth in curved neck, but growth in flask with broken off neck
- Proved organisms contaminating broth carried in air, not spontaneously generated
Describe the contribution of Pasteur and Koch to our understanding of infectious diseases
KOCH
Agar plate technique for growing microorganisms→ cultured bacteria; determined each disease caused by specific microorganism
Anthrax→ bacteria inserted into healthy sheep; showed spores obtained could cause disease→ evidence for germ theory→ microorganism grown outside body caused disease
Breakthrough→ discovery of bacteria responsible for Tuberculosis, bacteria for cholera
Postulates (principles for identifying microorganisms responsible for disease)
Same microorganism present in every diseased host
Microorganism must be isolated, cultured
Sample inoculated into host→ must display symptoms as original host
Must be able to isolate microorganisms from second host and culture and identify as original species
Perform an investigation to model Pasteur’s experiment to identify the role of microbes in decay
Beef stock cubes (make broth) and conical flasks with glass tubing bent into S (replace swan neck)
Filtered broth added to flask with straight piping and one with curve
Boil broth, leave in sub and check every few days→ scum, cloudiness, fungus, bubbles
Few weeks→ straight tubing should show signs of decay
Prions
Protein capable of causing disease→ no genetic material
Multiply in contact with normal prion proteins; alter structure and change them to infectious prions
Can’t be destroyed by heating or chemicals
E.g. Kuru disease→ through cannibalism
Viruses
Non cellular pathogens, contain genetic material, not composed of cells (30-300 nm)
Only can replicate in host cells→ enters and makes copies of itself
Cell becomes too full with copies; bursts→ releases them to repeat in other host cells
E.g. Influenza, herpes, glandular fever
Bacteria
Single celled organism (0.5-100um) → reproduce by binary fusion
Found everywhere (classified on basis of shape) → many beneficial
E.g. Cause food poisoning, anthrax, pneumonia
Protozoans
Single celled eukaryotic→ cell membrane, membrane-bound nucleus and organelles (1-300um)
E.g. Malaria, African sleeping sickness
Fungi
Eukaryotic organisms; have cell wall but different to plant cell wall
Microscopic to macroscopic→ no chlorophyll (can’t produce own food)
Most live on dead plant, animal material (decomposers)
E.g. Athlete’s foot (tinea) or black spot on rose plants
Macro- Parasites
Visible to naked eye; larger than other pathogens; multicellular eukaryotic
Tiny louse→ long tapeworm
Some transmit disease directly or act as vectors
Live outside host body (suck blood-mosquitos) or live inside body (tapeworm)
E.g. Flea is vector for bacteria causing plaque, plant disease→ aphids transmitting Banana Bunchy T
Gather and process info to trace the historical development of our understanding of the cause and prevention of malaria
1000 CE→ Chinese recognised disease
2000 YA→ Greeks described symptoms. Built drains to take away stagnant water
1880→ Charles Laveran discovered malaria causing pathogen
1897→ Ronald Ross discovered main stages of transmission, identified mosquito as vector
1898→ Grassi and Bastianelli→ showed human malaria is transmitted in the same way as malaria in birds
1898→ Draining stagnant water, spraying oil onto water to stop breeding, wearing protective clothes
1930→ Antimalarial drug (Atabrine) used. Discontinued due to side effects
1970’s→ Use of drugs as prophylactics to try and prevent the disease, Incidence of malaria decreased
1980’s→ Incidence of malaria increases
2000- present→ Combination drug therapy that includes highly effective aertesminsimin,. Netting treated with long term insecticide and other protective measures
Identify data sources, gather process and analyse info from secondary sources to describe one named infectious disease in terms of its :
Cause, Transmission, Host response, Major symptoms, Treatment, Prevention, Control
MALARIA CAUSE AND TRANSMISSION
CAUSE
Protozoa Plasmodium→ anopheles mosquito is vector
TRANSMISSION AND LIFE CYCLE
Female mosquito picks up gametes of parasite from blood of host→ fertilise in mosquito gut
Zygote matures, form sporozoites (move to salivary gland) injected into another host when feeding
Sporozoites move to liver cells; grow and multiply→ cells burst→ released into blood
Transferred back to feeding mosquito
Identify data sources, gather process and analyse info from secondary sources to describe one named infectious disease in terms of its :
Cause, Transmission, Host response, Major symptoms, Treatment, Prevention, Control
MALARIA HOST RESPONSE
In liver cells; isolated from immune system, but in RBC→ antibodies produced
Plasmodium avoids immune response as surface antigens change weekly→ not recognised by antibodies already produced by host
Identify data sources, gather process and analyse info from secondary sources to describe one named infectious disease in terms of its :
Cause, Transmission, Host response, Major symptoms, Treatment, Prevention, Control
MALARIA MAJOR SYMPTOMS
Cells burst→ parasite, toxins, haemoglobin breakdown released into plasma
Creates shivering, high fever, headache, sweating
Anemia→ from breakdown of RBC, haemoglobin
Identify data sources, gather process and analyse info from secondary sources to describe one named infectious disease in terms of its :
Cause, Transmission, Host response, Major symptoms, Treatment, Prevention, Control
MALARIA TREATMENT, CONTROL AND PREVENTION
TREATMENT
Antimalarial drugs→ reduce temp or cure infection
Some resistant strains→ oral quinine instead
PREVENTION
Travellers to malaria areas→ drugs prior to departure and after come back→ kill any from liver
Protective clothing, insect repellent, mosquito nets
No donating blood if been recently to infected area
Ships, planes, vehicles from areas→ sprayed with insecticides
CONTROL
Insecticides→ DDT spraying, or draining standing water
Vaccine being trialled
Identify the role of antibiotics in the management of infectious disease
Antibiotics; chemicals destroy or stop growth of bacteria causing disease (without destroying host)
Destroy cell membrane, or accumulate in bacteria cells preventing them forming new cell wall
Natural selection→ evolve resistant strains. Some bacteria possess natural resistance, survive and reproduce to build up population resistant to antibiotic
Process info from secondary sources to discuss problems relating to antibiotic resistance
Many no longer effective→ resistant strains forming→ dont respond to first line antibiotics; need 2nd or 3rd line (take longer to cure, more severe)
Superbugs→ virtually resistant to all; only treated with experimental drugs
Current trends→ in future, some diseases have no treatment due to resistant strains
Strategies:
- Prescription only for bacterial infections, and taken for entire course (not just until symptoms stop)
- Cleaning products with antimicrobial ingredients should not be used
Identify defence barriers to prevent entry of pathogens in humans:
Skin, Mucous membranes, Cilia, Chemical barriers, Other body secretions
SKIN
Prevents entry of pathogens→ microorganisms rarely penetrate intact skin
Certain bacteria on skin→ destroys incoming
pathogens
Lack of moisture→ limits growth of microorganisms
Identify defence barriers to prevent entry of pathogens in humans:
Skin, Mucous membranes, Cilia, Chemical barriers, Other body secretions
MUCOUS MEMBRANE
Membranes line nasal passages, digestive, respiratory tracts→ secrete mucus
Mucus traps pathogens until body disposes
Prevents membranes drying → provides moist surface for normal microflora
Identify defence barriers to prevent entry of pathogens in humans:
Skin, Mucous membranes, Cilia, Chemical barriers, Other body secretions
CILIA
Fine,mucus coated, hair like→ line nasal, respiratory surfaces
Beating of cilia→ moves mucus layer along (with any trapped microorganisms) in throat
Identify defence barriers to prevent entry of pathogens in humans:
Skin, Mucous membranes, Cilia, Chemical barriers, Other body secretions
CHEMICAL BARRIERS
Lysozyme (enzyme) → in tears, saliva, mucus, sweat, tissue fluid→ breaks up bacteria membrane
Stomach acid (pH 1-2) → lethal environment for pathogens
Bile and acidic urine fluid→ inhibits pathogen growth
Identify defence barriers to prevent entry of pathogens in humans:
Skin, Mucous membranes, Cilia, Chemical barriers, Other body secretions
OTHER BODY SECRETIONS
Tears→ wash surface of eye when blink→ prevents settling of microorganisms
Perspiration→ any microorganism in sweat glands washed away
Saliva→ washes microorganisms from teeth, into stomach lining (digestive enzymes, stomach acid destroy)
Urine→ cleans urinary tract,flushes out microorganisms
Gather, process and present info from secondary sources to show how a named disease results from an imbalance of microflora in humans
Disease/pathogen
Fungus Candida albicans → causes Thrush
(symptoms, treatment/prevention, conditions under which disease develops)
SYMPTOMS
- Itching/burning sensation when urinating or sexual intercourse
- Thick, white discharge
- Splits in skin, redness or swelling
TREATMENT/ PREVENTION
- Treatment→ vaginal creams, tablets
- Prevention→ women wipe from front to back when using toilet (avoids spreading yeast from anus)
CONDITIONS UNDER WHICH DISEASE DEVELOPS
- Usually kept low by competition from other micro-organisms→ but if balance upset, increase in C Albicans→ disease develops
- Balance upset by suppression of immune system, drug use, diabetes antibiotics treating bacterial infection→ reduced number of bacteria
Identify antigens as molecules that trigger the immune response
Antigen→ molecule recognised as foreign→ triggers immune response
Surface of cells in body→ markers identify as belonging to self→ protects from immune system attack
Pathogens have chemical markers (antigens) immune recognises as not belonging to body→ activate immune response (foreign particles)
Explain why organ transplants should trigger an immune response
New organ→ marker molecules on cell surface→ antigens different to markers on own cells
Organ identified as foreign→ immune response activated to attack and defend body
More number of matching macromolecules→ less foreign antigen molecules to fight
Identify defence adaptations, including
Inflammatory response, Phagocytosis, Lymph system, Cell death to seal off pathogen
INFLAMMATION RESPONSE
Response brought by infected/injured cells→ release chemicals for fluid containing phagocytes to enter tissues→ destroy invaders
Damage to tissue triggers response (characterised by pain, heat, swelling→ increased temp inhibits pathogen activity)
Destroys cause of infection or confines infection to small area. Replaces/ repairs damaged tissue
Identify defence adaptations, including
Inflammatory response, Phagocytosis, Lymph system, Cell death to seal off pathogen
PHAGOCYTOSIS
Phagocytes (macrophages, neutrophils) surround, enclose foreign particle→ then bathed in enzyme lysozyme (destroys it)
Neutrophils→ Immune cell, ingest bacteria in bloodstream, (then digested by lysozyme)
Macrophage→ Larger cell, wander around tissue collecting microorganisms or other foreign bodie
Identify defence adaptations, including
Inflammatory response, Phagocytosis, Lymph system, Cell death to seal off pathogen
LYMPH SYSTEM
Responsible for filtering lymph fluid, (remove pathogens, dead cells, debris)
Lymph nodes contain phagocytes (destroy foreign material brought by tissue fluid)
Lymphoid organs defend body→ fight infections in spleen, bone marrow, thymus gland
Identify defence adaptations, including
Inflammatory response, Phagocytosis, Lymph system, Cell death to seal off pathogen
CELL DEATH TO SEAL OFF PATHOGEN
If area badly infected, other responses can’t control pathogens→ layer of dead cells forms around infection site→ followed by layer of macrophages
Seals off and contains pathogens→ eventually die and consumed by macrophages
MACFARLANE BURNET’S WORK IN THE MIDDLE OF THE 20TH CENTURY CONTRIBUTED TO A BETTER UNDERSTANDING OF THE IMMUNE RESPONSE AND THE EFFECTIVENESS OF IMMUNISATION PROGRAMS
Examined body recognising itself and can use immune system to respond to foreign substances without invading own cells
Concluded that ability to recognise self is gradually acquired in fetal development→ predicted if tissue was introduced to foetus it would learn not to reject material
How body determines between self and nonself
Identify the components of the immune response:
Antibodies, T cells, B cells
ANTIBODIES
Proteins (produced by plasma cells) → in response to antigen
Antibodies seek out antigen and bind to part of it (forms antigen-antibody complex) → deactivates antigen
Antigens destroyed by antigen-antibody complex clumping together (easier to eliminate by phagocytosi
Identify the components of the immune response:
Antibodies, T cells, B cells
T- CELLS
Lymphocytes produced in bone marrow and mature in thymus gland→ released into blood, lymph nodes
Each T cell→ particular surface receptor protein (recognises specific antigen)
Encounter antigen, matching receptor→ activate and clone killer T cells→ move to infection; destroy infected cell
Identify the components of the immune response:
Antibodies, T cells, B cells
B- CELLS
Lymphocytes produced and mature in bone marrow→ released into blood, lymph nodes, tonsils
On surface→ different antibody specific to antigen→ encounter antigen (makes copies of itself) → forms plasma cells that produce specific antibodies
Antibodies move to infection site→ form antigen-antibody complex (deactivate antigen
Process, analyse and present info from secondary sources to evaluate the effectiveness of vaccination programs in preventing the spread and occurrence of once common diseases, including smallpox, diphtheria and polio
SMALLPOX
Before vaccine→ millions of deaths worldwide
1967 WHO introduces mass immunisation and follow up vaccines
Highly successful→ eradicated disease worldwide
Process, analyse and present info from secondary sources to evaluate the effectiveness of vaccination programs in preventing the spread and occurrence of once common diseases, including smallpox, diphtheria and polio
DIPHTHERIA
Before vaccine→ Thousands worldwide (1900’s)
1974 WHO expanded immunisation program→ aim to decrease children with disease
Still present today, but effective→ drop in global incidence to 8000 cases in 2005
Process, analyse and present info from secondary sources to evaluate the effectiveness of vaccination programs in preventing the spread and occurrence of once common diseases, including smallpox, diphtheria and polio
POLIO
Before vaccine→ Thousands of cases worldwide
1955→ Spain developed safe vaccine → 1997 Global Polio Eradication Initiative
70% reduction of cases→ rare in developed countries; but still concern in developing nations
Describe and explain the immune response in the human body in terms of:
Interaction between B and T lymphocytes
Macrophage engulfs foreign particle with antigen→ antigen on surface moved to macrophage surface
Macrophage presents antigen to helper T cell in lymph nodes (has receptor corresponding to antigen)
Helper T activates→ release cytokine chemicals activating production of B clones (antigen specific)
Also activate production of cytotoxic T clones (have particular antigen receptor on surface)
Immune response defeated→ suppressor T stops B and cytotoxic cell activity
The mechanisms that allow interaction between B and T lymphocytes
The mechanisms that allow interaction between B and T lymphocytes
System in place to identify cells both belonging to body→ stop them attacking each other
Surface of cells; MHC molecules allow recognition in body and identify foreign cells
MHCI molecules present on all nucleus cells→ recognise antigens for T cell to destroy
MHCII molecules on B cells→ recognition of antigens by B cells, helps helper T cell activate B and T
The mechanisms that allow interaction between B and T lymphocytes
Antibody- mediated immunity
B cells presenting antigens→ move to lymph nodes, inspected by helper T cells
T cells stimulate cloning of millions of B cells (specific to antigen presented)
B cells produce plasma cells→ secrete specific antibodies→ move via blood, lymph to infected area
Antigens, antibodies combine→ antigen-antibody complex (inactivates pathogens)
The mechanisms that allow interaction between B and T lymphocytes
Cell mediated immunity
Foreign material engulfed by macrophages→ then moves to lymph nodes; inspected by helper T
Helper T activate cloning of cytotoxic and memory T cells (specific to antigen)
Cytotoxic cells go to infection→ antigen, antibody bind → release chemicals to destroy cells
Chemicals increase inflammation, attract macrophages for phagocytosis
Infection defeated→ suppressor T cells release chemicals; stop production and action of cytotoxic
The range of T lymphocyte types and the differences in their roles
Memory T cell
Remain in body→ respond quickly to future invasions
Suppressor T cell
Stop immune response when infection defeated
Cytotoxic T cell
Activate and move to site of infection→ chemicals destroy infected cells
Helper T cell
Recognise antigen→ release chemicals activating cloning of T and B cells
Outline the way in which vaccinations prevent infection
Vaccine→ preparation containing dead or weakened pathogens→ can’t cause disease but act as antigens; stimulate immune response and memory
Causes multiplication of B and T cells without symptoms → vaccinated person gains immunity; when actual disease occurs→ body undergoes immune response and produces antibodies for that antigen
Outline the reasons for the suppression of the immune response in organ transplant patients
Donor organ→ marker molecules act as antigens (seen as foreign material) immune response initiated
Cytotoxic T cells activated→ attack cells, reject organ
To reduce severity of immune response; tissue of donor and recipient need to be closely matched
Drugs to suppress immune system to lower risk of rejection
Drugs reduce activity of T cells (main cells attacking) → advantage; whole immune system not suppressed, can still defend the body→ but not as effective
Much greater risk of infection (anti-rejection drugs needed for rest of life)
Identify and describe the main features of epidemiology using lung cancer as an example
Study of patterns of disease occurrence in human pop, hypothesises cause and strategies to control
Results used by public health authorities to develop strategies and evaluate ones already in place
Descriptive studies→ frequency of disease, geographical location, time period, who is affected
Analytical studies→ Statistics on mortality rates, incidence and prevalence
Intervention studies→ Test effectiveness of treatment or campaign
LUNG CANCER
Data collected on age, sex, smoking habits of smokers and nonsmokers
Case studies compare lung cancer and those without→ look for exposure (suggests smoking)
Cohort studies compare non smokers and smokers to establish link between lung cancer→ greater number of cigarettes smoked daily; greater chance of dying from lung cancer
Look at effectiveness of Quit campaign
Gather, process and analyse info to identify the cause and effect relationship of smoking and lung cancer
Cancer council→ 1 in 8 cancers from smoking (most common; lung cancer)
1 in 5 cancer deaths from smoking→ smoking biggest factor for preventable cancer
High risk of developing when exposed to cigarettes→
more smoked; greater risk of cancer
Identify causes of noninfectious disease using an example from each of the following categories:
Inherited diseases, Nutritional deficiencies, Environmental diseases
INHERITED DISEASES
Genetically transmitted; errors in genetic infi
May be change in chromosome number or defect in single gene (mutation)
E.g. Cystic fibrosis→ mutation to gene causes secretion of thick mucus
Blocks passageways into lungs, digestive tract→ problems with breathing, nutrient absorption. No cure.
Identify causes of noninfectious disease using an example from each of the following categories:
Inherited diseases, Nutritional deficiencies, Environmental diseases
NUTRITIONAL DEFICIENCEIS
Unbalanced diet,or physiological conditions leading to poor diets (anorexia)
E.g. Scurvy from not getting enough vit C, or anemia from missing iron
Identify causes of noninfectious disease using an example from each of the following categories:
Inherited diseases, Nutritional deficiencies, Environmental diseases
ENVIRONMENTAL DISEASES
Lifestyle related (substance abuse) or physical environment (exposure to uv rays)
Disease caused from exposure to chemicals→ e.g. asbestos causes mesothelioma
Cancer of cells in membrane on outside of lung→ asbestos fibres penetrate lining and damage cells causing mutations→ mesothelioma
Identify data sources, plan and perform a first hand investigation or gather info from secondary sources to analyse and present info about the occurrence, symptoms, cause, treatment/management of a named non-infectious disease
SCURVY
OCCURENCE
Rare in developed countries→ mainly in developing where fresh fruit and veg not freely available
Occur in all age groups→ alcoholics, elderly, infants
SYMPTOMS
Swollen, purplish gums
Swelling, painful legs
If left untreated; gangrene, haemorrhaging, death
CAUSE
Nutritional deficiency→ lack of vit C (needed for connective tissues, bones)
Deficiency weakens blood capillary wall→ bleeding, bruising
TREATMENT/MANAGEMENT
Increase amount of vit C in diet→ or vit C supplements
Prevention→ eat foods rich in vit C (orange, lemons,cranberries)
Discuss the role of quarantine in preventing the spread of disease and plants and animals into Australia or across regions of Australia
Quarantine→ isolation of organisms to control spread of disease
All animals coming into Australia→ required to spend time in quarantine (ensure free of disease)
Policy protects health of humans, environment→ reduced rate of disease incursion
Prevents introduction, establishment or spread of disease/pests
E.g. Rhinos from Africa commonly have internal parasites; could transfer to native fauna
Perform an investigation to examine plant shoots and leaves and gather first hand evidence of pathogens and insect pests
LEMON PLANT
Pest→ insect leaf miner
Insect eats leaf layers→ causes leaf to curl
ROSE BUSH
Fungal pathogen→ Black spot
Yellowing of leaves, black powdery mildew
ROSE BUSH
Pest→ Aphid
Small leaves, stunted leaf growth
Explain how one of the following strategies has controlled and/ or prevented disease:
Public health programs,
Govt regulations; Sterilising hospital equipment, cook/prepare food→ prevents spread of pathogens
Govt regulations; garbage disposal, drinking water and sewerage treatment→ prevents occurrence
Laws for reporting diseases→ allows early detection
and strategies to be implemented
Encourage regular screening for disease; e,g women check breast for lumps (cancer detection)
Childhood immunisation program→ prevent disease incidence (e.g. whooping cough)
Education programs; awareness of lifestyle risk factors (E.g. Quit campaign→ images of side effects)
Process and analyse information from secondary sources to evaluate the effectiveness of quarantine in preventing the spread of plant and animal disease into Australia or across regions of Australia
Many plant species refused entry; or allowed in if treated to ensure no pests
Some restrictions on movement of fruit → prevents spread to disease free areas
Quarantine checkpoints on main roads leading to each state (prevents risk material entering)
If disease enters Aus; quarantine, control of movements, slaughter or vaccination of infected animals
Observation and decontamination→ establish disease free areas
E.g. Swine Flu 2007→ horse movement banned, equipment decontaminated, → no swine Flu 2008
Gather and process information and use available evidence to discuss the changing methods of dealing with plant and animal diseases, including the shift in emphasis from treatment and control to management or prevention of the disease.
TREATMENT AND CONTROL OF DISEASE
USE OF PESTICIDES
Controls spread of vectors and pests; E.g DDT to kill mosquito (malaria)
Harms environment and can lead to resistant strains developing
USE OF ANTIBIOTICS
Treats many type of bacterial infections; destroys bacteria and cures person
Overuse and wrongful use → development of resistant strains
MEDICAL INTERVENTION PROCEDURES
E.g. Cancer treatment by surgery radiation, chemotherapy→ if successful cures patient
Side effects of treatment severe and increase suffering of patient
Gather and process information and use available evidence to discuss the changing methods of dealing with plant and animal diseases, including the shift in emphasis from treatment and control to management or prevention of the disease.
PREVENTION AND MANAGEMENT OF DISEASE
VACCINATION
Prevents person from contracting the disease; decreases prevalence of disease
E.g. vaccination against diphtheria; only small percentage suffer side effects
QUARANTINE
Prevents entry into Aus; management procedures prevent spread around country
Decreases incidence of disease and protects agricultural industry allowing them entry to export markets with disease free products
GENETIC ENGINEERING
Plants and animals produced that are resistant to pathogens/pests→ prevents occurrence of disease
Reduces need for spraying crops with pesticides
Effects on biodiversity unknown; could be harmful
E.g. Bt cotton that produces natural insecticide to kill caterpillar larvae
PUBLIC HEALTH PROGRAMS
Reduces incidence of disease in population
E.g. public education programs; no smoking to prevent lung cancer
