B6.3 Monitoring and maintaining health Flashcards
What is the definition of a disease?
A condition caused by any part of the body not functioning properly - can be mental or physical
What is good health?
Not having any type of disease
What is a communicable disease?
- can be spread between organisms - (AKA contagious / infectious disease)
- caused by pathogens (e.g. viruses, bacteria, fungi, Protozoa)
What is a non-communicable disease?
- can’t spread between organisms
- caused by poor diet, genetic disorders, obesity
What is epidemiology?
Branch of medicine which deals with incidence, distribution and possible control of diseases
Factors affecting spread of communicable disease
- close contact individuals - e.g. schools, hospitals
- poverty
- hygiene
- education
Preventing spread of communicable diseases in humans
- inhalation - cover mouth/nose when cough/sneeze
- cuts/bites to skin - protection from animal bites (insect repellent) - dont share needles
- food & drink - wash hands before - cook food thoroughly - drink clean water
- sexual inter course - use protection
Spread of disease in plants
- through soil/water in which plants grow
- insect vectors (carriers)
- wind - blows fungal spores between plants
- direct contact - sap from infected plant transferred to healthy plant by tools/feeding animals
Preventing spread of communicable diseases in plants and animals
- burn diseased plant
- avoid moving animals around
- clean tools/machinery
- chemical dips on farms to avoid spread of pathogens on feet
- kill infected animals if untreatable
- vaccinate animals/treat with drugs
- spray plant with fungicide
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Monitoring the spread of a communicable disease
E.g. Ebola - the disease is monitored regularly over a short period
Monitoring the spread of a non-communicable disease
E.g. lung cancer - the disease will be monitored over a long period of time with many cases
In good conditions bacteria divide every…
…20 minutes - this is exponential growth
What are physical plant defences?
barriers that prevent entry of microorganisms
- e.g. cellulose cell walls - structural barrier
- waxy cuticle layer - stops pathogens coming into contact with epidermal layer
What are chemical plant defences?
Chemicals secreted by the plant that kill microorganisms
-e.g. anti fungal and antibacterial compounds
Identifying plant disease in the field
- Observation - look for visual symptoms - e.g. mottled leaves & rotten fruit
- microscopy - finds pathogen responsible for disease (can normally be identified using light microscope but sometimes needs electron microscope is needed)
Identifying plant disease in the lab - DNA analysis
- DNA analysis/fingerprinting - each plant pathogen has a unique set of DNA (genome) which produces a unique pattern/DNA profile (e.g. barcode)
Identifying plant disease in the lab - identifying antigens
- identifying antigens - antigens are proteins found on surface of cells - each pathogen has specific antigens which can be used to identify them - diagnostic kits can be used by farmers to identify common crop pathogens
What’s is the advantage of lab techniques over field ones?
Can identify plant pathogen before it causes significant damage to crop - in field, disease can only be identified once symptoms are apparent (disease has already taken hold)
What are non-specific body defences?
- non-specific as prevent entry of all microorganisms
First lines of defence (non-specific body defences)
- saliva & tears - antibacterial enzymes
- skin - prevents entry
- stomach acid - low pH kills harmful microbes
What is the incubation period of a disease?
- time delay between a pathogen entering your body and you feeling unwell - pathogens grow + reproduce rapidly (causes damage to cells) - some pathogens produce toxins which cause symptoms such as fever + rashes
What is the skin?
Main barrier to infection but if broken, pathogens can enter the body
Why do scabs form?
Form to prevent pathogens entering the body and to prevent blood loss
What are platelets?
Small fragments of cells made in bone marrow
- have no nucleus
- help blood to clot at site of a wound
