B6.3 Monitoring and maintaining health + Non-communicable diseases Flashcards
Disease
Condition caused by any part of the body not functioning properly,
causing physical effects
Different between communicable and non-communicable disease
Communicable diseases - diseases that can be spread between organisms - infectious or contagious disease
Non-communicable diseases - diseases that cannot be spread between organisms
Health
State of complete physical, mental and social well-being (as defined by the WHO)
Pathogen
Microorganism which causes disease
Examples:
Fungi
Bacteria (e-coli)
Virus
Protozoa
Why are people with HIV more likely to catch tuberculosis
HIV causes AIDs
Weakens their immune system
Makes them more susceptible to infection with tuberculosis and other infections
How can pathogens be spread between animals
Droplet infection - respiratory system, inhaling pathogens
Eating contaminated food or drink - digestive system
Through cuts in the skin
Sharing needles
Direct contact
Sexual intercourse
How can pathogens spread between plants
Vectors such as insects
Wind - fungal spores blown
Direct contact with sap of infected plant
Ways spread of animal disease can be reduced
Covering mouth/nose when coughing/sneezing
Not touching infected people of objects
Using protection - protective suits, masks, shields
Not sharing needles
Hand washing
Cooking food properly
Drinking clean water
Insect repellent / nets
Methods of prevening diesease in plants and animals used in farming
Burning dieseased plant material
Herd slaughtering - BSE, foot and moth diseasw
Drugs & isolation of diseased animals
Movement / transport bans upon diesease animals
Chemical dips to kill pathogens upon aminals and footwear
Vaccination programs
Fungicides
Pesticides
Bacterial disease affecting humans
Samonella - Found in raw meat, eggs, unwashed raw vegetables and unpasturised milk
Transimmted by ingesting infected food
Symptoms = fever, sickness and diarrhoea
Campylobacter - Found in raw meat, unpasturised milk and untreated water
Transmitted by ingesting infected food
Symptoms = fever, sickness and diarrhoea
E.Coli - Found in raw and undercooked meat, unpasturised milk and dairy products
Transimmted by ingesting infected food. Symptoms = fever, sickness and diarrhoea
Bacterial disease affecting plants
Crown gall disease (Agrobacterium tumefaciens)
Transmitted through cuts in the stems of plants
Plants display tumor type growths
Tumours encircle stem / trunk cutting off flow of sap
Viral disease that affects humans
Human Immunodeficiency Virus (HIV) - Transmitted through bodily fluids
Symptoms: rash and fever like symptoms (intial), invades immune cells preventing them from producing antibodies, leading to AIDs
Human Papilloma Virus (HPV) - Transmitted through sexual intercourse
Symptoms: throat warts, cancers of the genitals, head, neck, and throat
Viral disease that affects plants
Tobacco Mosaic Virus (TMV)
Transmitted through direct contact
Symptoms include spots and a yellow coloured mosaic pattern
Infects chloroplasts of plant leaves and reduces plant’s ability to photosynthesise
Fungal disease that affects animals
Athletes foot
Transmitted through direct contact or contact with skin particles (on shared towels/socks/shoes)
Dry cracked skin between the toes
Fungal disease that affects plants
Erysiphe graminis (barley powdery mildew)
Transmitted through vectors like aphids in cold damp environments
Symtpoms include powdery growth and yellowing on the opposite side of the leaf
Physical plant defences against disease
Thick cell wall
Waxy cuticle
How plants use chemical defences to prevent disease
Insect repellents to repel insect vectors e.g. pine resin & citronella
Insecticides e.g. pyrethrins made by chrysanthemums
Antibacterial compounds e.g. phenols which disrupts bacterial cell walls & defensins which disrupts bacterial cell membranes
Antifungal compounds e.g. chitinases which breakdown fungal cell walls and caffeine which is toxic to fungi and insects
Antimicrobial chemicals e.g. cyanide production when plant cell attacked
How plant disease can be identified
Analysis DNA to see whether the plant contains any pathogen DNA
Antigen detection to find any foreing antigens present in the plant
Obervation of symptoms
Microscopy
Function of platelets
Small fragments of cells that are involved in blood clotting
How a scab forms
Skin is cut and starts to bleed
Platelets change the blood protein fibronogen into fibrin which is fiberous
Fibrin forms a network of fibres in the cut
Red blood cells are trapped in the fibre to form a clot
The clot hardens to form a scab
Human body’s defence mechanisms against microorganisms
Skin - Physical barrier - sweat glands produce oils the help to kill microorganisms
Scabs - prevent microorganisms entering via wounds
Stomach acid - low pH kills pathogens
Cillia & mucas in airways - trap & waft
Nasal hairs
Tears - contain lysozymes kill pathogens
Earwax
White blood cells - phagocytes & lymphocytes
Function of white blood cells
Phagocytes are involved in phagocytosis - engulfing pathogens and then producing enzymes that digest the microorganism (non-specific)
Lymphocytes make antitoxins or antibodies (specific)
Antibodies
Proteins found on surface of lymphocytes (white blood cells) that bind to antigens upon surface of microorganism
Once bound the pathogen can be engulfed by a phagocyte cell
Each antibody only binds to one type of antigen
New antibodies must be made by lymphocytes every time a new type of microorganism enters the body (primary response)
WBCs are able to make the same antibodies more quickly if infection occurs again (secondary response)
Monoclonal antibodies
Laboratory generated antibodies used in diagnositcs and treatment
How monoclonal antibodies are produced
Genetically modified mice are injected with antigens:
The mouse produces an immune response producing lymphocytes with antibodies specific to the antigen
The antibody prodcuning lymphocytes are collected and fused with myeloma (cancer) cells from the bone marrow
The fused cell is called a hybrioma
The hybridoma grows rapidly forming clones which produce the antibody
The antibody is harvested = monoclonal antibodies
Uses of monoclonal antibodies
Pregnancy tests
Detection of cancerous tissue
Drug delivery to cancer cells
Identificaton of pathogens
Drug testing
Difference between anitbiotic and antivirals
Antibiotics kill bacteria
Antivirals inhibit reproduction of viruses
Antiseptics
Substances applied external to the body to kill pathogens
How vaccines work
Dead or inactive pathogens are injected into the body
Antigens in vaccine stimule lymphocytes to make antibodies against the pathogen
Antibodies lead to the destruction of antigens without risk of you getting the disease
Memory cells are created to provide long term immunity
“Halo” around discs of bacterial growth called, caused by antibiotics
Zone of inhibition
Aseptic technique
Approach to working, which prevent cross-contamination from unwanted microorganisms
Important steps when culturing microorganisms in the laboratory
Clean surfaces with alcohol
Wear gloves
Autoclave glassware and apparatus before and after use
Keep the culture closed until it is needed
Use a bunsen burner to sterilise wire loop
Work close to the bunsen burner flame
Stages in development of new medicines
Research the drug and test it upon lab grown cells
Test the drug upon animals - data from TWO animal species required in the UK before testing upon humans
Clinical trial 1 - test upon healthy volunteers
Clinical trial 2 - test upon a small sample of people with the disease
Clinical trial 3 - test upon a large number of people with the disease
If all stages passed approval granted by the MRHA
Continued studies undertaken after approval to monitor side effects
3 R’s principle
Reduction - smallest number of animals possible
Refinement - improving experiements to avoid unnecessary suffering and improve animal care
Replacement - where possible, replacing animals with other techniques e.g. cell cultures or computer models
Non-communicable diseases
Coronary Heart disease
Bonchitis
Diabetes mellitis type 1 & 2
Cancer
Liver cirrhosis
Alzheimer’s Disease
Epilepsy
Osteoarthritis
Osteoporosis
Chronic Obstructive Pulmonary Disease (COPD)
Cerebrovascular Disease (Stroke)
Coronary Artery Disease
Commonly identified harmful substances in tobacco smoke
Tar - Sticks cillia together preventing them wafting mucus away from the lungs causing smokers cough
Collects in the lungs
Carginogenic
Nicotine - Addictive drug
Makes your heart beat faster, narrows blood vessels leading to increase blood pressure & stoke
Carbon monoxide - Attaches to the haemoglobin in RBCs stopping oxygen from binding making the heart work harder leading to CHD
Particulates - small peices of solid
These are engulfed by WBCs relesing an enzyme that weakens the walls of alveoli preventing proper inflation - emphysema
Treatments are available for cardiovascular disease
Angioplasty - A stent can be surgically implanted to keep arteries open
Statins can be taken to lower cholesterol levels
Pacemakers can be inserted to maintain heart rhythm
Heart transplant or artificial valves can be inserted
Betablockers can be taken to lower blood pressure
Nitrates can be taken to widen blood vessels allowing more blood to flow through at a lower pressure
Antiplatelets to reduce stickiness of blood platelets and therefore clotting
Bypass surgery using vessels from other areas of the body
Lifestyle changes a person with cardiovascular disease should make
Healthy balanced diet - reducing processed foods
Exercise more
Drink less alcohol
Stop smoking
What is meant by cancer
Disease where cells in the body begin to divide uncontrollably
How embryonic stem cells are used to treat medical conditions
Testing new drugs for safety and effectiveness
Growth of tissues/organs with no concern of rejection
Reversing damaged caused by disease by:
Manufacturing brain cells - Parkinson’s
Rebuilding bones and cartillage - arthritis
Making replacement heart valves
How risk of rejection is minimised in transplantation
Tissue matching
Immunosuppresant drugs
Risks associated with the use of stem cells in medicine
Long-term side effects unknown
Rejection of foreign materials
Potential increased risk of cancer
Ethical issues surrounding use of embryonic stem cells
Gene therapy
Placement of a fully functioning allele into a cell containing a faulty allele for the same gene
Benefit and risk of gene therapy
Benefits - Replacement of faulty genes, reversal of chronic disease, lasting results, improvement in life quality
Risks - Virus used to deliver could cause harm, increased risk of cancer, inflammatory response, sepsis, infection, targeting wrong cells
Personalised medicine
Preventing and treating diseases tailored specifically to the patient’s GENOME
