Health Flashcards
Health definition
The state of physical and mental well-being
Disease definition
Disorders that affect part or all of an organism
What are communicable diseases ?
Diseases caused by infections that can be passed from person to person eg. measles or flu
What are non-communicable diseases ?
Diseases not caused by infections, which cannot be passed from person to person eg. cancer and diabetes
Impact of disease to individuals
Affects health and well-being
Impact of disease to families
Affect mental well-being - worry
Financial cost - if wage earner is ill
Impact of disease on local communities
Financial cost - taxes
Support groups taking care of those affected
Impact of disease on whole countries
Cost of treating ill individuals
Whole sections of workforce out of work
Correlation defintion
Patterns that occur which could indicate a relationship between two things
Does not mean one causes the other
Casual mechanism definition
One factor influences another through a biological process
Risk factor definition
Any attribute that increases the likelihood of developing a disease or injury
How does exercise influence health ?
Risk of injury
Improves mental wellbeing
Increased muscle strength - less arthritis and fractures
Improves cardiovascular health - lower risk or CHD
Less fat storage - less obesity
How does diet influence health ?
Less LDL - less risk of CHD
Protein supports muscle development
Nutrient deficiencies
Fats - Obesity, Type 2 diabetes, Arthritis
What is carbon monoxide ?
Poisonous gas found in tobacco smoke. Reduces the oxygen carrying capacity of blood.
Irreversibly binds tightly to haemoglobin, meaning it can’t carry oxygen.
Why are smokers often out of breath ?
10% of RBCs can be carrying carbon monoxide after 1 cigarette.
What is tar ?
Sticky black substance that accumulates in lungs
What affect does tar have on the lungs ?
Reduces surface area, leading to severe breathlessness and eventually death. Can break down the alveoli, causing Chronic Obstructive Pulmonary Disease.
Also a carcinogen
Chronic Obstructive Pulmonary Disease
Blocks bronchioles with mucus, breaks down alveoli ( emphysema )
Effects of nicotine on the body
Lightheadedness
Enlargement of aorta
High insulin
Muscle spasms
Increased or decreased heart rate
Effect of smoking on a foetus
Unable to get enough oxygen, leading to low birthweight or stillbirth
Effects of passive smoking
25% more likely to get cancer if living with a smoker
Every year, 17000 children are admitted to hospital for inhaling smoke
Cirrhosis
A disease, caused by alcohol, that destroys liver tissue. Active liver cells are replaced with scar tissue, so cannot carry out functions.
Alcohol - carcinogenic
Increases risk of liver cancer, which spreads rapidly so is difficult to treat
Alcohol consumption - effects on brain
Causes parts of the brain to turn soft, meaning they can’t function properly.
Effects of alcohol on pregnancy
Alcohol absorbs across the placenta into the developing foetus. The developing liver cannot handle the alcohol, so can cause irregular development in foetuses ( Fetal Alcohol Syndrome )
Ionising radiation
Radiation penetrates cells and damages chromosomes, causing DNA mutations. These can lead to the development of cancer.
What is cancer ?
A breakdown in the cellular control mechanism that limits cell division.
Cells that should be stable continue to divide, forming a tumour.
What is a tumour ?
A swelling that can occur almost anywhere in the body.
Made up of a mass of abnormal cells that divide continuously.
Can be malignant or benign.
Risk factors that lead to cancer development
Hereditary factors / genetics
Diet
Smoking
Radiation
Chemical carcinogens
Microbes
Benign tumours
Growths of abnormal cells which are contained in one area, usually within a membrane.
Can grow very large but do not destroy surrounding tissue.
Do not invade other parts of the body.
Malignant tumours
Destroy surrounding tissue
Their cells break away and spread through the blood and lymph into other sites ( metastasis ), where they form secondary tumours.
Why is cancer dangerous ?
Tumours interfere with the activity of the cells in the tissues of the organ that surround them.
Benign tumours can compress tissues, preventing normal blood flow or nerve functions.
Malignant tumours invade surrounding tissues and kill normal cells.
Chemotherapy
Chemicals stop cancer cells dividing or cause them to self-destruct.
Removes all possible tumours, but has intense side effects.
Radiotherapy
Cancer cells are destroyed using targeted doses of radiation. Stops cancer cells dividing.
Would stop tumour from growing, but would not target possible secondary tumours.
Surgery to remove cancer
Takes out tumours. Can also take out malignant tumours if early enough.
Would remove the whole tumour, but would not remove possible secondary tumours.
Pathogen defintion
A microorganism that causes disease
Vector definition
Any agent that carries and transmits an infectious pathogen in another living organism
How is disease transmitted ?
The air ( coughing and sneezing )
Physical contact ( hand shakes, kissing / sexual activity )
Contaminated water
Infected surfaces
Contaminated food
Size of bacteria
0.2 - 5.0 micrometres
Site of bacteria reproduction
The body
Effects of bacteria on the body
Produces toxins that damage cells and tissues
Example of bacterial infection
Salmonella
Size of viral cells
5 - 400 nanometres
Site of virus reproduction
Within host cells using host DNA - in the body
Effects of viruses on the body
Cell damage - cells burst open
Examples of viruses
Covid-19
Flu
Size of Fungi cells
3 - 10 micrometres
Site of fungi reproduction
Surface of organism, using hyphae which produce spores
Examples of fungi
Toadstools
Mushrooms
Moulds
Size of protist cells
10 - 100 micrometres
Site of protist reproduction
Within the blood
Effects of protists
Chills and fever
Example of protist infection
Malaria
What pathogen does measles involve ?
Virus
How is measles transmitted ?
Talking, coughing and sneezing cause the expulsion of tiny droplets into the air. Inhaling droplets that carry the virus allow measles to spread.
Symptoms of measles
Fever, red rash
Measles prevention and treatment
Most young children have vaccinations to protect them against measles
What pathogen is involved in Human Immunodeficiency Virus ?
Virus
How is HIV transmitted ?
Direct contact - Spread via sexual intercourse, exchange in bodily fluids, drug users sharing needles
Symptoms of HIV
Damaged WBCs, meaning they cannot kill infected cells.
Fewer lymphocytes
Inappropriate immune system responses
Preventions and treatments of HIV
Antiretroviral drug : prevents the virus entering the lymph nodes
What pathogen is involved in Tobacco Mosaic Virus ?
Virus
How is TMV transmitted ?
Enters via wounds : the virus gains access through a break in the skin or plant epidermis.
Symptoms of TMV
Mottles or discoloured leaves
Curled leaves
Stunted growth
Yellow streaks or spots on leaves in a mosaic pattern
Preventions or treatments of TMV
Removal of infected plant material
Controlling pests
Sterilising tools with heat
Washing hands after handling infected plants
Removing weeds
What pathogen is involved in salmonella ?
Bacteria
How is salmonella transmitted ?
Transfer through food
Bad hygiene
Symptoms of salmonella
Fever
Abdominal cramps
Diarrhoea
Preventions and treatments of salmonella
Poultry vaccinations
What pathogen is involved in gonorrhoea ?
Bacteria
How is gonorrhoea transmitted ?
Sexual intercourse / contact
Symptoms of gonorrhoea
Yellow or green discharge from urethra or vagina
Pain when urinating
Preventions of treatments for gonorrhoea
Antibiotics, however resistant strains have appeared
Contraception
What pathogen is involved in Rose Black Spot ?
Fungi
How is Rose Black Spot transmitted ?
Needs warm, wet conditions to grow and spread
The fungus produces spores which are released in wet, humid conditions
Wind helps for spores to disperse
Symptoms of Rose Black Spot
Black spots on the outside of the leaf, yellow around the spots
Drooping leaves
Small, black scabby lesions on stems
Prevention and treatment of Rose Black Spot
Immediately remove infected leaves
Treat infections with fungicides
Disinfect gardening tools
Burn infected plants
What pathogen is involved in Malaria ?
Protist
How is malaria transmitted ?
Spread by female mosquitos
Using dirty needles
From mother to baby
Symptoms of malaria
Recurrent episodes of fever
Sweats and chills
Muscle pains
Headaches
Diarrhoea
Cough
Preventions and treatments of malaria
Spraying pools of water with insecticide to kill mosquitos
Draining stagnant water pools
Spraying pools to prevent larvae from breathing
Using mosquito nets to avoid bites
Taking drugs to kill the protist in the blood
In depth explanation of malaria transmission
Female mosquitoes feed on blood ; if she bites an infected individual she will pick up the Plasmodium through her mouthparts and it will exist in her saliva.
She will then inject it into the next individual. Plasmodium passes to the host liver via the blood. It will then multiply here, then infect RBCs. They then burst, releasing Plasmodium into the bloodstream.
It can then be picked up by a new vector.
Ways to identify plant disease
Stunted growth
Spots on leaves
Areas of decay
Abnormal growth
Malformed leaves or stems
Discolouration
Presence of pest
Why is it important to control plant disease ?
Destroys crops
Hard to control
Loss of species
Knock on effect in the food chain
Loss of medicines
Symptoms of Aphid infestation
Deceased growth rate
Mottled or yellow leaves
Low yield
Wilting
Death
What happens during an Aphid infestation ?
They feed on phloem sap, reducing turgor pressure so the plant wilts.
They release a sticky honeydew that encourages mould growth.
This encourages ants or herbivorous predators to the plant. Any disease they carry then enters the phloem during feeding.
They can inject pathogens in their saliva into the plant.
Holes left from aphids feeding can then lead to secondary infections.
How to control aphid infestations
Squash aphid colonies
Encourage natural aphid predators eg ladybirds
Insecticide
Why is nitrate important to plants ?
To make amino acids, which are used during protein synthesis for growth.
What does a nitrate deficiency cause ?
Stunted growth
Why is magnesium important to plants ?
Needed to make chlorophyll
What does a magnesium deficiency cause ?
Lack of chlorophyll made ( chlorosis ), resulting in yellow leaves
How to identify specific plant diseases
Refer to garden manual or website
Take the plant to a laboratory to identify the pathogen present.
Using testing kits that contain monoclonal antibodies - bind to the pathogen on the test strip.
Physical plant defences
Cellulose cell wall
Tough waxy cuticle
Layers of dead cells ( bark )
Chemical plant defences
Anti-bacterial chemicals
Poisons to deter herbivores
Mechanical plant defences
Thorns + hairs
Leaves which curl when touched
Mimicry
