B5 Communicable Diseases Flashcards
What is health ?
your state of phsycial and metnal well-being partly based on a person’s perception and not just abscence of disease .
what is a communicable disease
communicable diseases are caused by pathogens (bacteria and viruses ) that can be passed from one person to another .
what are non communicable diseases
cannot be passed from one eprson to another and are not infectious
example of commmunicbale disease
tuberculosis and flu
exampe of noncommunicabl diseases
heart disease and arthiritis
three things that can cause illl health
diet- not getting enough to eat anaemia or eating too much , cancer type 2 diabetes syress - mental healht and heart disease life situations; gender part of the whorld u live level of free health care you have
what is a pahthogen
microorganism that cause disease .
example of how one disease effects you getting nsother
tb ( lung disease) most people can fight of tb how some people have a defective immune system , such as people suffering from hiv , so they are much more likely to suffer from an infectious disease .
one disease causes anothr disease example
hpv , harmless but for some poeple can cause cervical cancer .
example of diseases triggered by immune system
eg allergies
wht are allergies
the immune system fights of the pathogen but is left iwth an allergy
mental illness can be triggered by physcial illnes
arhirtis - very difficult to move - so can cause someone to feel isolated and derpessed .
what causes infectious idsease
pathogens
exmpaes of pathogens
virus , fungi , portist
true or false infections effect both plants n animals
truee
example of a bacterial disease
food poisioning
how do bacteria make us ill
once inside the human boyd , bacteria reporudce very rapidly (in good conditons every 20m)
bacteria then release harmful chemicals called toxins
toxins damage tissues and make us feel ill .
example of a virus disease
HIV
Difference between virus and bacteria
viruses cannot reporudce themsleves , they can only reproduce in a host ceel wheres bacteria can .
how do viruses make us ill
first , the viurs invades the host cell
the virus now reproduces inside the host cell
this is very damaging to the cell as when the virus leavs the cell it cann cause the cell to burts open and die infecting neighbouring cells
how do pathogens spread (just listed)
by air
water
direct contact
example of disease spread by air and how it makes us ill
eg water droplets (influenza) when you are ill , you expel droplets full of pathogens from your breathing system , when you cough , sneeze or talk . Other people breathe in the droplets congaining the pathogens so they pick up the infetcoion .
example of disease spread by water and how it eneters and how it makes us ill
cholera , , pathogen enters the body thorugh the digesitve system , by drinking water contanugn sewage .
example of direct contact diease and how it makes us ill
HIV and hepatitis , sexually tranmited infection - chlamydi - hiv
cuts scratches - acess to blood
animal vectors carrying vectors betwene infected and uifnected poeple .
ways to prevent the spread of ptahogens
washing and hands and clean water - prevent the spread of pathogens .
Using a condomg befor intercoure reduces spread of HIV
Highly infectious diseases such as EBOLA u should isolate the person to prevent pathogens from being spread
Vaccination
destroying or controlling vectors - malria , denguf fever - if vector destroyed spread of disease prevented . If prevented spread greatly reduced .
what doctor /scientist showed that microoragisms cause diseae
louis pasteur
what scientis heloded develop vaccines and against what
louis pasteur agains rabies and anthrac
which doctor /scientist realsied that hand washing can prevent the spread dof infections
semmelweis
which scientist / doctor using antiseptic chemicals to destroy pathogens in operating theatres?
joseph lister
Which development helped convince people that microrganisms cause disease
microscopes
example of a disease spread by a vector
malaria
why can’t vaccines protect plants agianst disease .
plants do not have immune system
what is vacination
inteoducing small quantities of dead or inactive forms of pathogen into the body .
how does vacciation work ?
As the pathogen is dead or inacitve , it cannot lead to the disease in the patient .
The white blood cells are now stimualted to produce antibodies agaisnt the dead or inactive pthogen .
At the same time , the white blood cel divides by mitosis to produce lots of copies of itself .
These copies of the white blood cell can stay in the blood for decades .
If the sam epthogen now enetes the body even yers later , the white bllood cells cn produce hte ocrrect antibodies quickyl to rpevent infection .
why is important large number of people get vaccinagted , what is this known as
lrge number of people getting vaccinates irs rlly improtant as there are lways some that arent vaccinaged , if enough people are vaccinated it lalso protects other people
so the unvasccianted person cannot catch the dsese as no one around them can pass the pathogen known as HERD IMMUNITY
what are the the bodies two main defense systems called
non specific
immune system
what does the non specific defence system do
it prevents pathogens from enterig the body
list a few non specific defence systems
skin
nose hiar , mucus
cillia
how does the skin help against pathogens
skin forms proectve layer covering the body
- the outer layer of the skin consits of dead cells and is difficult for pathogens to penetrate .
- the skin also produces an oily substance called sebum which can kill bacteria .
sometimes the skin is damaged which could allow [pathogens to enter the body . To stop this , the skin scabs over .
what does the nose have to prevent pathogens from enetring
the nose has hair+ mucus - they can trap pathogens before entering the immune system .
what can happen if the nose dosent prevent athogens from entering
the pathogens can pass through the nose an dmake thier way to the lungs
what defence do we have to stop pathogens making their eways to the lungs
the trachea and bronki are covered with tiny ahirs called cillia .
Cillia are covered in mucus which can trap pathogens.
The cillia now waft the mucus upwards towards the throat , where it is swallowed into the stomach .
how does the stomach defend agaisnt pathogens
to protect us , the stomach relases HCL this kills pathogens before they make their way further into the digestive system
t/f the non specific defnse systems will get rid of all pthogens
FALSE pathogens sitlli get into our body . to protect us , we have the immune system .
what two functions doe the immune system have
1.the immune system destroys pathogens and any toxins they produce
the immune system protects us incase the ame type of pathogen invades again in the future .
what are the two types of white blood cells
phagocytes and lymphocytes
what is a role of a phagocyte
ingests (englufs by phagocytosis) microorganisms and destroys them .
Explain phagocytosis
The white blood cell detects chemicals released by the pathogen and moves towards it .
The white blood cell then ingests the pathogen .
This is phagocytosis
what are the two roles lymphocytes
produce antibodies - which are complemnetary to specific antigens on a pathogens surface .
produce antitoxins to neutralise toxins by the pathogen
explain lymhocytes producing antibodies
antibodies are portein moleules produced by white blood cells .
The antibodies stick to the pathogens .
This triggers the pahtogen to be destroyed .
Two key facts about antibodies
antibodies are specific (measles ntibiodies ONLY protect you from meases , no other pathogen )
Antibodies can remain in the blood for a long time , so can pprotect us if we get infected by the same pathogen .
explain lymphocyts producing antitoxins
certain types of bacteria can relase toxins . These are chemicals which can make us feel unwell .
White blood cells can produce chemicals called antitoxins .
Antitoxins stick to toxin molecues and prevent them from damaging cells .
what happens when a person because reinfected iwth a diease ?
if the body becomes reinfected , memory lymphocytes are prepred . So memory lymphocytes respond much more quickly and make more of the right antibodies quickly .
How do bacteria multiply
By simple cell division .
One bacteria splits into two bacterial cells (binary fission) .
How often do bacteria carry out binary fission ?
Bacteria can carry out binary fission once every 20 minutes as long as they have enough nutrients and the temperature is suitable .
What is the formula for working out number of bacteria .
2 to the power of number of divisions found .
Question , a certain type of bacteria divides every 20 minutes . Calculate the number of bacteria present after three hours .
How many times bacteria divides in 3 hrs
360=180minutes
bacteria divide every 20 minutes .
180/20=9 ronds of diision
number of bacteria =2 to the power of number of division found
2to the power of nine =512 bacteria present .
STANDARD FORM
512 now count the number of digits after this in htis cse 2 .
so
5.1210to the power of 2
How can we grow bacteria ?
- Using a nutrient broth solution .
- The bporth contains all the nutrients bacteria neds to grow and divide .
- The borth is loudy as it contains a large number of bacteria.
How do we set up the agar gel plate ?
(nutreint broth turned into a jelly using a vhrmical agar)
- poured into a petri dish and put to set .
- On agar gel platr , bacteria grows divisible colonie s.
Need to avoid contamination making broth solution or agar plate . how do we do this ?
- sterilise all petri dishes , bacterial nutrients , broh and agar .
- bacteria then transfered into culture using inoculating loop , sterilised using bunsen burner flame .
- then attach lid using adhesive tape , stoping unwanted microrganisms fromentering .
why is the agar plate then turned uspdie don.
stops mositure form dripping down onto the bateria disrupting colonies .
-Bateria is incubate d at 25 degress as this reduced the chance any harmful bacteria wil grow .
What is the first stage of the rqp ?
Clean the bench with disenfctant solution .
-This kills microrogansism that could contaminate the culture .
What is the second stag eof the rqp ?
-Sterilise an incoulating group by passing it through a bunsen burner flame.
What is the third stage of the rqp ?
Open a sterile agar gel plate near a bunsen burner flam e.
-Flame kills any bacteria int he air .
What is the fourth stage of the rqp ?
Now use the loop to spreafd the chosen bacteria evenly on the plate .
What is the ffifth stage of rqp ?
Place a sterile filter paper disc contaning antibiotic into plate .
Incubate at 25 degrees.
What happens after a few days rwp ?
- Bacteria forms a layer on the surface of the agar gel .
- Around the antibiotic discs , we have a region where the bacteria has not gorwn . This is called the zone of inhibition .
How do we measure the effect of the ntibiotic .
Measure the zone of inhibiotn find the area of it using
pie r squared .
Plants can be attacked by insects like aphids .
.
-Aphids extract nutrients such as sugars stunting growths .
Some ways to detect disease ?
-Discolouration
Insects like aphids .
Spots on leaves
Stunted growth
Some other ways to detect disease ?
Decay or rot
Malformed stems or leaves .
Ways to identify a disease ?
- We can use a garden manual oe website .
- We can take an infected plant to a lab to identify the pathogen .
- We can use testing kits containing monocolonal antibodies .
What does a lack oif nitrate ions cause ?
- Causes stunted growth .
- As nitrate is needed for protein synthesis and therefore growth .
A lack of magenesium ions ?
Causes the ondition chlorosis , because magnesium is required to chlorphyl. (looses green colour) .
What are the thre main defences plants have if they are attacked ?
- Physical
- Chemical
- Mechanical .
Physical defences .
Cell wall - difficult for microorganisms such as bacteria to penetrate .
- Leaves are covered with a thin oily layer called the waxy cuticle .
- The waxy also makes it dificult for microroganism to penetrate , protecting the plant from attack .
Another physical defence .
Bark on trees .
Bark is a barrier to entry by microrganisms . As bark ages it eventually falls of it . As it is replaced with fresh bark underneath .
Chemicla defences ?
- Plants can release antibacterial chemicals which kill bacteria and prevent them from attacking the plant .
- Plants can also release posions to deter herbivores from grazing on the plant .
Mexhanical defence ?
- Sharp thorns - directly protect a plant from being eatn by a herbivore .
- Other plants have ahirs which irritte the mouth of herbiovres making the plant difficult to eat .
Another mechanical defence .
Sometimes we find plants that have a special leaf that can droop or curl when touched .
-This might scare herbivores as they are not used to plants that move like this .
Final mechanical defenc e.
Mimiciry - white dead nettle - look like stirnigign nettle back has no sting .
- Herbivores are less liekly to eat white dead nettle as they can easily misrake it for a stining nettl e.
- Protecting it from getting eatne .
