B2 Flashcards
what is disease?
a condition that commonly damages cells of the host and impairs the functioning of the organism
what are the causes of disease?
infection, mutation, environmental conditions, trauma, lifestyle
what is a communicable disease?
a disease that can spread between organisms
what causes disease?
pathogens infecting the bacteria
what is a pathogen?
type of microorganism that causes disease
- bacteria, viruses, protists and fungi
what is a non communicable disease?
disease that cannot be passed onto another organism
examples of non communicable disease
cardiovascular and respiratory diseases, cancers and diabetes
what are symtoms?
changes in the organism that indicate disease is presnt
what is the incubation period
time between being infected with a pathogen and showing symptoms of the disease
what are bacteria?
- very small cells that can reproduce rapidly
- they produce toxins that damage cells and tissues
what are viruses?
- not cells
- replicate themselves inside the infected organism’s cells which then burst and releases the viruses
what are protists?
- eukaryotic, single celled and vary in size
what are fungi?
- have hyphae, thread like structures
- hyphae can grow and penetrate human skin and the surface of plants
- can produce spores that can be spread
how are communicable diseases spread?
water, air, on surfaces, body fluids, animal vectors, soil, food
water transmission
- drinking or bathing in dirty water
- cholera gets spread by contaminated water by the diarrhoea of other sufferers
air transmission
- pathogens can travel by the wind and in the air
- airborne pathogens can be breathed in by others
- flu, chalara ash dieback
surface transmission
- touching contaminated surfaces
- in plants, TMV when infected leaves rub against healthy leaves
- in humans, touching the same things as an infected person
- tobacco mosaic disease, athletes foot
body fluids transmission
- blood, breastmilk, semen
- exchange of body fluids
- HIV is a virus spread by exchanging body fluids , which gives flu like symptoms. the virus enters the lymph nodes and attacks the immune system so it cants cope with other infections or cancers. by this part, its known as AIDS or late stage HIIV
animal vectors transmission
- animals that spread disease are called vectors
- malaria from mosquitoes that pick up protists and when it feeds on an animal, it inserts the protists into their blood, causing fever
soil transmission
- comes from pathogens that live in the soil
- bacteria that causes crown gall disease live in soil and once it enters a plant is can grow galls which damages the plant tissue
food transmission
- can come from eating contaminated food
- salmonella is found in some foods like raw meat
- if kept for too long or not cooked property, it can cause food poisoning
defence systems
- non specific
- always presnt
- physical, microbial or chemical
physical defences
mucus and cilia in respiratory tracts
- mucus traps pathogens and cilia wafts pathogens to back of the throat
skin
- acts as a barrier
platelets
- helps blood clot helping to plug the wound
chemical defences
eyes
saliva
stomach
eyes as defence
tears produce lysozyme which break down bacteria on surface of eye
saliva as defence
contains molecules that kill pathogens that enter the mouth
stomach as defence
produces hydrochloric acid which kills pathigens
microbial defences
pathogens that make it past the saliva and stomach and enter intestine where they compete with the bacteria that live there to survive
phagocytosis
phagocytes have a flexible membrane, allowing them to engulf foreign cells and digest them
antibodies
Antibodies work by recognizing and binding to specific pathogens, such as viruses and bacteria. This binding process neutralizes the pathogen and marks it for destruction by other components of the immune system. The immune system also remembers the pathogen, so if it infects the body again in the future, the immune system can respond more quickly and effectively.
antitoxins
Antitoxins are substances produced by the immune system to neutralize toxins produced by harmful bacteria. They work by binding to the toxins and inactivating them, preventing them from causing harm to the body.
how reduce and prevent spreading diseases in animals
- being hygienic
- sterilising wounds
- living in sanitary conditions
- destroying infected animals
- isolating infected animals
- vaccination
- contraception
how to reduce and prevent spreading diseases in plants
- regulating plant movement
- destroying infected plants
- crop rotation
- polyculture
- chemical control
- biological control
how to regulate plant movemnet?
make sure infected plants dont come into contact with infected ones
polyculture
growing different types of plants in a single area
chemical control
fungicides can be used to kill fungal infections but can lead to the evolution of resistant strains
biological control
one organism is used to control a pest or pathogen
the immune system
- destroys pathogens that make it past defence systems
- they consume pathogens then produce antibodies and antitoxins
- contains white blood cells
what is vaccination?
dead, inactive or weakened pathogens are injected into the body
what is phagocytosis?
- Phagocytosis is carried out by a special type of white blood cell called a phagocyte.
- The first step is for the phagocyte to track down a pathogen, and then bind to it.
- The phagocyte’s membrane will then surround the pathogen and engulf it.
- Finally, enzymes inside the phagocyte break down the pathogen in order to destroy it.
whjat does an antitoxin do?
Bind and neutralise the toxins produced by bacteria
what is a risk factor?
something that increases someones chance of getting that disease
what can be some risk factors?
lifestyle, environment and genes
how can some diseases happen?
by other risk factors interacting with others
–> genetic variant and poor diet could give you cancer
why does exercise decrease risk of disease
- more energy used, decreasing body fat stored
- builds muscle which boosts metabolic rate
why does lack of exercise increase risk of disease?
lack of exercise increases blood pressure
what does eating too much lead to?
obesity
what does obesity lead to?
type 2 diabetes, high blood pressure and CVD
what does too much saturated fat lead to?
increased cholesterol
what leads to coronary heart disease?
too much bad cholesterol in the blood, causing fatty deposits to form in artery walls
what can eating too little lead to?
malnurition
hat does malnutrition lead to?
fatigue and poor resistance to infection
what causes deficiency diseases?
lack of vitamins or minerals
what can reduce risk of non communicable diseases?
healthy, balanced diet
as well as exercise
how does alcohol affect the liver
its broken down by enzymes in the liver and has toxic products
–> this causes the death of liver cells, forming scar tissue that stops blood reaching the liver, causing cirrhosis
how does alcohol cause CVD
too much increases the blood pressure
how does alcohol cause cancer
the toxic products damage DNA and cause cells to divide faster than normal
what are the products of fags
nicotine, tar, carbon monoxide and particulates
how does smoking cause CVD
- carbon monoxide reduces how well blood carries oxygen and if the cardiac muscle doesnt get oxygen, it leads to a heart attack
- nicotine increases the heart rate meaning the heart contrats more, increasing blood pressure
how can smoking cause cancer?
tar has carcinogens, creating mutations in the DN leading to uncontrollable cell division
how does smoking cause lung disease?
smoke causes inflammation of bronchi and bronchioles (lining) causing permanent damage
how does smoking affect pregnancy?
causes health problems for the baby
global trends
- lack of excersise and high alc consumption suggests high income
- smoking deaths are common in poorer countries
why is obesity a problem for all globally?
- higher income people can afford high fat food
- lower income people are eating cheaper, less healthy foods
national trends
- deprived areas are more likely to smoke, have poor diet and not do physical activity
- this means they are more likely to have heart disease, obesity, type 2 diabetes and cancer
what do individual life choices do?
if you choose to smoke, drink, have a bad diet and not exercise, you increase your risk
what is your recovery rate?
the time it takes for the pulse rate to return to the resting rate
what is a high resting rate and a slow recovery rate linked to?
non communicable diseases
what can reduce resting heart rate and speed up recovery rate?
regular exercise
what does regular exercise reduce?
non communicable disease
what do long term studies do?
help scientists determine what kind of exercise or length of training programme is most effective for improving resting heart rate, allowing them to make lifestyle recommendations
what are painkillers?
- drugs that relive pain and symptoms
- don’t tackle cause of disease or kill pathogen
what else do drugs do?
reduce how severe the symptoms are or how long they last for
what are antibiotics?
chemicals that kill bacteria without killing body cells
how are antibiotics made?
produced naturally by fungi and pharmaceutical companies can grow them on a large scale
what are antivirals used for?
treat viral infections
why are antivirals hard to produce?
viruses use host cells to replicate so its hard to target the virus without damaging the cell
what do antivirals do?
stop the virus from reproducing
what does the misuse of antibiotics do?
increases the rate of development of resistant strains
how do resistant bacteria become more common?
- bacteria with the most resistance have survived the treatment
- since there is less competition, they can grow and reproduce more easily
how can we avoid antibiotic resistance?
- give antibiotics only when needed
- complete the full course
- take the right amount of dosage
how are atheromas formed?
when fatty deposits inside arteries harden
what is coronary heart disease?
when the arteries that give blood to the heart are filled with atheromas, as this restricts blood flow to the heart
what causes a blood clot?
when bits of atheromas break off or damage the blood vessel
what causes heart attack?
complete blockage of an artery or blood vessels
what causes stroke?
if the blood vessel blockage is in the brain
what lifestyle changes can prevent CVD?
healthy diet, regular exercise, stopping smoking
what do statins do?
reduce the amount of cholesterol in the bloodstream, slowing down the rate of fatty tissues
what are anticoagulants?
drugs which make blood clots less likely to form
what are antihypertensives?
they reduce blood pressure which makes atheromas and blood clots less likely to form
side effects of statins
kidney failure, liver damage and memory problems
side effects of anticoagulants
causes excessive bleeding if person is hurt
side effects of antihypertensives
headaches or fainting
what are stents?
tubes inserted inside arteries, keeping them open so blood can pass to the heart
- over time, the artery can get irritated, making scar tissue grow over the stent
what is coronary bypass surgery?
if part of a blood vessel is blocked, a healthy vessel can be taken from somewhere else
donor heart
- a heart gets donated
- it might not pump properly
- the immune system could reject the heart bcs its seen as ‘foreign’
risks of heart surgery
bleeding, clots and infection
preclinical testing
- drugs are tested on cultured human cells
- drugs are tested on live animals
why is preclinical testing done?
to test if the drug is effective and find out how safe it is
clinical testing
- drug gets tested on healthy volunteers
- drug is tested on person with disease
what is the placebo test?
placebo effect occurs when someone feels they are better when they have been given a dummy form of the drug, not the drug itself
what is a blind clinical trial
a trial where the people taking part don’t know which treatment they are getting out of the real piece or a placebo
what are double blind tests?
the patient nor doctor knows who has the placebo
why are trials blind?
so doctors monitoring and analysing arent subconsciously influenced by their knowledge
