B5 Health and Disease Flashcards
Define
health.
the state of complete physical, mental and social well-being and not merely the absence of disease or infirmity
Define
physical wellbeing.
being free from disease, eating and sleeping well, getting regular activity and limiting the intake of harmful substances such as alcohol and other drugs
Define
mental wellbeing.
how you feel about yourself
Define
social wellbeing.
how well you get on with other people and also how your surroundings affect you
Define
communicable disease.
a disease, such as flu, that is caused by pathogens that can be passed from an infected individual to others
Define
non-communicable disease.
a disease, such as heart disease, that is caused by problems in the body and cannot be passed to people near you
What are the
stages of liver damage?
healthy liver > fatty liver > liver fibrosis > cirrhosis
Why is a cirrhotic liver bad?
it does not function well and can result in death
Define
malnutrition.
not getting the right amount of calories and/or not getting the correct balance of nutrients
What is obesity caused by?
a diet that is high in sugar and fats where large amounts of fat are formed under the skin and around organs such as the heart and kidneys
What can obesity lead to?
many diseases, such as cardiovascular disease which may lead to a heart attack
When does a heart attack happen?
When a coronary artery gets blocked
A build up of fatty diposits in the walls of the arteries can reduce the amount of blood flow to the heart. A clot can form at these build-ups and stop the blood from flowing to a part of the heart - so a heart attack begins.
Why are heart attacks bad?
Glucose and oxygen (that are carried by blood) can no longer get past the blockage and that part of the heart may now be damaged, struggle to beat and eventually die.
What factors increase the chances of having a heart attack?
- diet
- stress
- smoking
What is the formula for BMI?
weight(kg) / (height(m))^2
What BMI is classifed as obese?
an adult with BMI >30
What fat is most closely linked to cardiovascular disease?
abdominal fat
What is the equation for waist:hip calculations?
waist measurement / hip measurement
this can give a better method of measuring abdominal fat than BMI
What WHR increases the risk for heart disease and other conditions?
1.0 or higher in both men and women
Why is smoking bad for you?
Tobacco contains many harmful substances that can damage the lungs when they are breathed in.
Some of these substances are absorbed from the lungs into the blood and transported around the body.
These substances can damage blood vessels, increase blood pressure, make blood vessels narrower and increase the risk of blood clots forming in blood vessels.
How is cardiovascular disease treated?
With a combination of lifestyle changes, medicine and, in some cases, surgery.
What are some examples of lifestyle changes?
(to treat cardiovascular disease)
(to reduce the risk of future episodes)
- stop smoking
- exercise
- eat healthily
What are some examples of surgery?
(to treat cardiovascular disease)
(usually determined by an aniogram)
- by-pass surgery
- angioplasty
- heart transplant
What are some examples of medicine?
(to treat cardiovascular disease)
(to reduce blood pressure/widen arteries)
- aspirin (antiplatelet)
- statin (cholesterol)
- beta blockers (prevent angina and treat high blood pressure)
- vasodilators (nitrates which relax blood vessels, widening them)
- ACE inhibtors (block the activity of a hormone called angiotensin II, which causes the blood vessels to narrow)
What is an
angiogram?
a type of X-ray used to examine blood vessels
Define
pathogen.
a microorganism which causes disease
What are some examples of pathogens?
viruses, bacteria, fungi, protists
What are some properties of bacteria?
and some diseases they cause
- unicellular
- prokaryotic (no nucleus)
food poisoning, lime’s disease, TB
What are some properties of viruses?
and some diseases they cause
- non-cellular
- genetic material
- protein coat
- (non-living?)
covid, common cold, influenza, AIDs
What are some properties of fungi?
and some diseases they cause
- both multicellular and unicellular
- eukaryotic
athlete’s foot, ringworm, thrush
What are some properties of protists?
and some diseases they cause
- unicellular
- eukaryotic
malaria
What is cholera caused by?
a bacteria
(Vibrio cholerae)
What does cholera infection result in?
diarrhoea, which can cause death
(large amounts of very watery faeces)
Where does cholera occur?
where drinking water is not kept seperate from human waste
e.g. in emergency camps after a disaster
How is the cholera bacterium spread?
faeces from a patient coming into contact with food or water and being ingested
How can cholera be prevented?
- vaccine
- sanitation
- boil water
- wash hands
- avoid uncooked food
What is tuberculosis caused by?
(TB)
a bacteria
(Mycobacterium tuberculosis)
(which infects the lungs)
How is tuberculosis spread?
(TB)
through droplets in the air resulting from coughs and sneezes
these spread easily when people live close together
What does tuberculosis lead to?
(TB)
can lead to death
What symptoms does tuberculosis cause?
(TB)
- coughing up blood
- weight loss
- fever
How can the spread of tuberculosis be reduced/prevented?
(TB)
- vaccination
- wear a mask
- isolate the infected person
What does the disease chalara dieback affect?
ash trees
What is chalara dieback caused by?
a fungus
(Hymenoscyphus fraxineus)
What does chalara infection cause?
leaf loss in the bark of the trees and dieback (when the leaves on the ends of branches die first, before infection spreads to the rest of the branch)
What is malaria caused by?
a protist
What does malaria do?
infects and damages red blood cells and liver cells.
What are mosquitos in relation to malaria?
vectors
they drink the infected blood and spread it from person to person
How can the spread of malaria be reduced or prevented?
mosquito nets, anti malarial medicine
What is HIV caused by?
(Human Immunodeficiency Virus)
a virus
What does HIV do?
(Human Immunodeficiency Virus)
it destroys T cells, leading to AIDS
HIV damages the cells in your immune system and weakens your ability to fight everyday infections and disease
(Acquired Immune Deficiency Syndrome)
How can HIV be transmitted?
(Human Immunodeficiency Virus)
- unprotected sex
- used needles
- childbirth
- breast milk
What are the symptoms of HIV?
there aren’t any
Is there a cure for HIV?
(Human Immunodeficiency Virus)
no
:(
What are stomach ulcers caused by?
a bacteria
(Helicobacter pylori)
What happens when Helicobacter pylori is in a patient’s stomach?
although 50% of people have this bacteria in their stomach, only 20% develop sore areas (ulcers) where the bacteria attack the stomach lining
What causes ebola?
a virus
How does ebola affect the patient?
It causes the breakdown of blood vessels, kidney cells and the liver. This leads to internal bleeding (haemorrhaging) and fever.
How is ebola transmitted?
via bodily fluids - specifically blood
What is the basic structure of all viruses?
- one or more strands of genetic material (DNA or RNA)
- surrounded by a protein coat (capsid)
- many viruses have an additional layer called an envelope
Why can’t viruses replicate outside a living cell?
Because viruses need the cell machinery (e.g. ribosomes) to make copies of themselves.
What are the two types of virus lifecycles?
lytic and lysogenic pathways
What happens in the lysogenic pathway?
the virus’s genetic material is inserted into the cell’s genetic material and copied at the same time
no new viruses are made
What happens in the lytic pathway?
many copies of the virus’s genetic material are made seperately from the cell’s genetic material
many new viruses are made
How can we study the effect of viruses?
using bacterial lawn plates
(bacteria grown on nutrient agar)
viruses are added and after a day or two, clear circles can be seen where bacteria have been killed by the viruses
How is a thick cuticle a method of plant defence?
It makes the leaf tougher to eat and more difficult for pathogens to get into the leaf cells. The cuticle also contains wax. This helps water (which may contain pathogens) run off easily.
What type of plant defence is a thick cuticle?
physical
How are hairy leaves, stems or thorns a method of plant defence?
- they put herbivores off
- they make it more difficult for pathogens to get to the leaf surface
some plants have additional adaptations to their hairs
e.g. nettle leaves and stems have hairs that contain a substance which irritates skin
What type of plant defence are hairs and thorns?
physical
but can release chemicals in some instances (e.g. nettles)
How is bark a method of plant defence?
- it helps to protect the trunk from cold in winter, or drought during the summer
- bark contains substances that are poisonous to many herbivores
(tannin)
What type of plant defence is bark?
physical and chemical
How are cell walls a method of plant defence?
cell walls are thick and contain substances that make it difficult for most pathogens to get into the cell
What type of plant defence are cell walls?
physical and chemical
How are lectins a method of plant defence?
- lectins bind to carbohydrates
- they reduce the amount of carbohydrate that the herbivore can absorb from what it eats
- lectins also interfere with reactions involving carbohydrates in the animal’s body, which causes harm
lectins are sometimes sprayed on crops
What type of plant defence are lectins?
chemical
Define
symptom.
something that you feel as a result of a disease
What does aspirin do?
controls the symptoms of pain or fever
Where did aspirin come from?
it was originally produced from salicylic acid which is made by several plants including willow trees
What does artemisinin do?
it kills the Plasmodium protists that cause malaria
Where did artemisinin come from?
it was originally extracted from the wormwood plant
Define
aseptic technique.
using practices and procedures to prevent contamination from pathogens
What are the three different types of yellow leaves?
- too little water
- magnesium deficiency
- fungal infection by tomato leaf mould
What are the visible symptoms of too little water?
(in plants)
yellow leaves that start from the bottom of the plant
What are the visible symptoms of magnesium deficiency?
(in plants)
yellow leaves with plant ‘veins’ showing
What are the visible symptoms of fungal infection?
(in plants)
spotty/patchy yellow/brown leaves
How could the distribution of plants with yellow leaves help to identify the problem as a lack of water?
generally all of the plants near it would have yellow leaves
How could the distribution of plants with yellow leaves help to identify the problem as a lack of magnesium?
all of the plants near it would be affected
because it is due to the soil
How could the distribution of plants with yellow leaves help to identify the problem as a fungal infection?
yellow leaves would spread widely (and further than the other two), especially along the wind direction
What lab or field test could confirm the cause of yellow leaves to be lack of water?
a soil moisture test
What lab or field test could confirm the cause of yellow leaves to be magnesium deficiency?
a soil test
(to test for nutrients)
What lab or field test could confirm the cause of yellow leaves to be fungal infection?
a DNA test
(of the plant)
What are the two causes of curled leaves?
(in plants)
- tomato leaf curl virus
- contamination of soil with weedkiller
How could the distribution of plants with curled leaves help to identify the problem as leaf curl virus?
the infected plants should spread over time to non-neighbouring plants in different fields
How could the distribution of plants with curled leaves help to identify the problem as weedkiller in soil?
the infection should affect all neighbouring plants with the weedkiller in its soil
What lab or field test could confirm the cause of curled leaves to be leaf curl virus?
genetic analysis in a lab
What lab or field test could confirm the cause of curled leaves to be weedkiller in soil?
a soil lab test
Why is blood clotting useful if we cut ourselves?
- it prevents too much blood loss, and blood is necessary to transport oxygen (and glucose) around the body
- it prevents the cut from getting infected
- it turns into a scab to help the wound heal
What chemical defences do human bodies have?
- liquid on eyes
- mucus in nose
- ear wax in ears
- saliva in mouth
- stomach acid in stomach
- acidic in genitals
What physical defences do human bodies have?
- liquid on eyes
- eyelashes
- eyelids
- hairs in nose
- skin
Define
Sexually Transmitted Infection
(STI)
sexually transmitted disease (STD) is the same thing
an infection that is transmitted via bodily fluids through sexual contact
What is chlamydia caused by?
a bacteria
What age group is chlamydia most common with?
people under 25
because they are most likely to be having sex and spreading the STI
What are the symptoms of chlamydia?
- a burning pain when urinating
- thick yellow or green discharge
- for women it can cause bleeding between periods
- for men it can cause swelling of the testicles
If untreated, what can chlamydia lead to?
infertility
How is chlamydia treated?
by antibiotics
What are the two types of white blood cells in blood?
phagocytes and lymphocytes
What do phagocytes do?
they engulf bacteria by endocytosis and digest them using enzymes
What do lymphocytes do?
produce antibodies
What are antibodies?
Proteins that recognise and bind to specific antigens. They lock onto antigens leading to the direct destruction of pathogens by phagocytes.
What is an antigen?
a protein that is found on the surface of a cell that binds to an antibody
Why are a huge number of different types of lymphocytes needed?
a lymphocyte can only produce one type of antibody
How are lymphocytes activated and what happens when they are?
- the antigens of a pathogen bind to the antibodies in the surface membrane of the lymphocyte
- this activates the lymphocyte
- the active lymphocyte divides by mitosis to produce a clone of many identical cells
- the clone cells start to produce large quantities of the same antibody
- this is the same antibody needed to defend against the pathogen
Why are many different antibodies stimulated?
because most pathogens have more than one antigen on their surface so more than one type of lymphocyte is needed
these are called polyclonal antibodies
Why is there a much faster reponse if an antigen invades your body a second time?
When lymphocytes are dividing during the primary response, some cells stop dividing and secreting antibody and become memory cells. Large numbers of memory cells remain in the body for a long time and these are capable of producing large amounts of antibody very quickly when stimulated.
How do vaccines work?
- vaccines are small amounts of dead or inactive forms of the pathogen
- lymphocytes detect the pathogen/specific antigen and produce antibodies specific to the antigen
- antibodies cause the pathogen to clump together and phagocytes engulf and digest the pathogen
- most of the lymphocytes that make the antibody die, a few of the stay in the blood, these are called memory cells
- if you meet the pathogen again, the memory cells will produce antibodies to attack and destroy it rapidly
- the pathogen is destroyed without making you ill
- you now have immunity to the pathogen
What are the advantages of immunisation?
- prevents disease
- reduces death rates
- reduces pressure on health services
- combats pandemics
What are the disadvantages of immunisation?
- expensive
- health risks
- side effects
- time needed for development and testing
- distribution
- misinformation
Define
herd immunity.
a form of immunity that occurs when the vaccination of a significant portion of a population provide protection for individuals who have not developed immunity
How does herd immunity work?
- vaccinated individuals disrupt the chain of infection
- the greater the proportion of the population are resistant, the smaller the probability that a susceptible individual will come into contact with an infectious individual
What are antibiotics?
drugs which are used to treat bacterial infections
that do not kill human cells
What are the two types of antibiotics?
bacteriocidal and bacteriostatic
What are the differences between the two types of bacteria?
Bacteriocidal - kills the bacteria
Bacteriostatic - slows down the growth
What are the key stages of developing new medicines?
(including antibiotics)
- discovery
- development
- preclinical testing
- clinical testing
What are the stages of development when creating a new medicine?
- test the medicine on cells or tissues in a lab (preclinical) to tell if the medicine has the required effect
- test the medicine on animals (preclinical) to see how the medicine works in a whole body (without risk to humans
- test the medicine on a small number of healthy people (clinical) to check that the medicine is safe and that side effects are small
- test the medicine on many people who have the disease (clinical) to help work out the correct dose and to check for different side effects
Define
antibody.
A protein produced by lymphocytes in response to and counteracting a specific antigen.
They work within the immune system to destroy pathogens that have entered the body.
How do pregnancy tests work?
By detecting a hormone only produced during pregnancy.
They have to be very sensitive and use antibodies specifically made to match the hormone. They need large amounts of these identical antibodies that we call monoclonal antibodies.
Describe the process of making
monoclonal antibodies.
- A particular antigen is injected into a mouse. The mouse produces lymphocytes that make antibodies against the antigen.
- Cancer cells are grown in a culture medium.
- The lymphocyte cell from the mouse and the cancer cell are fused together to make a hybridoma cell.
Why are hybridoma cells good?
they can both divide and make antibodies against the injected antigen
What are the disadvantages of chemotherapy and radiotherapy?
they lead to other healthy cells being killed which can have extreme side effects
How can monoclonal antibodies help to treat cancer?
Cancer drugs can be attached to monoclonal antibodies so that they are delivered to just the cells that need treating. This reduces the amount of drug needed to kill the cancer cells and reduces the risk of damaging healthy cells.
