WINDOW 2 health & disease Flashcards
health
according to the WHO (world health organisation)
a state of complete physical, mental and social wellbeing and not just the absence of disease and infirmity
disease
a condition where part of an organism doesn’t function properly
communicable and what are they cause by
can be spread between individuals, caused by a pathogen
non communicable
can’t be transmitted between individuals
ebola (type of pathogen, symptoms, transmission method, method of reduction)
virus
haemorrhagic fever
spread via bodily fluids
reduced by isolation of individuals and sterilisation of areas
chalara ash dieback (type of pathogen, symptoms, transmission method, method of reduction)
fungus
leaf loss and bark lesions
carried through air by wind or when infected tree is moved
reduced transmission by removing young infected trees, replanting with a different species and restricting movement of ash trees
malaria (type of pathogen, symptoms, transmission method, method of reduction)
protist
red blood cell damage and liver damage
transmitted by mosquitoes, which act as vectors
transmission can be reduced by using mosquito nets and insect repellent
cholera (type of pathogen, symptoms, transmission method, method of reduction)
bacterium (vibrio cholerae)
diarrhoea
spread by contaminated water sources
reduced by ensuring access to clean water
tuberculosis (type of pathogen, symptoms, transmission method, method of reduction)
bacterium (mycobacterium tuberculosis)
coughing and lung damage
spread via air when individuals cough
reduced by avoiding public spaces, practicing good hygiene and sleeping alone in a well ventilated home
stomach ulcers (type of pathogen, symptoms, transmission method, method of reduction)
bacterium (helicobacter pylori)
stomach pain, vomiting and nausea
spread via oral transmission (eating or drinking)
reduced by access to clean water and hygienic living conditions
chlamydia (type of pathogen, symptoms, transmission method, method of reduction)
bacterium
no symptoms but can cause infertility
transmitted by bodily fluids
reduced by wearing a condom, screening individuals for treatment or avoiding sexual contact
HIV (type of pathogen, symptoms, transmission method, method of reduction)
virus
kills white bloods cells, causing immune system to deteriorate and eventually fail , and leading to AIDS
transmitted by infected bodily fluids
reduced by wearing a condom, not sharing needles and medication
virus
one or more strands of genetic material surrounded by a protein coat/capsid
viruses have to infect living cells to reproduce
what are the two virus pathways/life cycles
lytic pathway
lysogenic pathway
what happens in the lytic pathway (4)
1) virus attaches to host cell and genetic material is injected
2) proteins and enzymes in host cell are used to reproduce genetic material and make new viral components
3) virus components assemble
4) host cell lyses (bursts) releasing the new viruses which infect more cells
what happens in the lysogenic pathway (4)
1) the virus attaches to the host cell and genetic material is injected
2) injected genetic material is incorporated into the host cell’s genome
3) the viral genetic material is replicated each time the host cell is replicated, but the virus remains dormant
4) eventually, a trigger causes the genetic material to leave the genome and enter the LYTIC pathway
3 examples of physical barriers in the human body
- skin
- hairs and mucus in nose trap particles potentially containing pathogens
- cells in trachea and bronchi produce mucus trapping particles, the mucus is then wafted by cilia cells to the back of the throat where it can be swallowed
2 examples of chemical barriers in the human body
- stomach produced hydrochloric acid (very strong acid) that kills pathogens
- eyes produce lysozyme chemicals which kill bacteria on the eye’s surface
describe the response of the immune system to a pathogen (5)
- white blood cells look for pathogens
- B-lymphocytes find an antigen on a pathogen
- B-lymphocytes start to produce antibodies
- antibodies bind to the pathogen so that it can be found and destroyed
- antibodies are quickly reproduced - they flow around the body looking for all similar pathogens
what is the role of memory lymphocytes
when a new pathogen first enters the body, our immune response is slow as there aren’t many B-lymphocytes available to make the antibody required to match the antigen
as well as antibodies being produced, memory lymphocytes are made that remain and recognise an antigen
this means that the person has the ability to quickly respond to a 2nd infection more strongly (secondary immune response)
immunisation
injecting dead or inactive pathogens into the body
how does immunisation give the patient immunity (3)
the pathogens injected contain antigens which causes the body to make specific antibodies to destroy them
memory lymphocyte production is triggered
if live pathogens then enter the body, there are already memory lymphocytes present to trigger a secondary immune response
2 advantages of immunisation
- epidemics can be prevented if a large percentage of the population is immunised
- some diseases have been virtually wiped out due to immunisation programs
2 disadvantages of immunisation
- doesn’t always work
- you can have a bad reaction to a vaccine, although this is rare