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