infection and response 🎀 Flashcards
what are the four types of pathogen?
virus, fungi, bacteria, protist
what is a communicable disease?
a disease that can be spread from one person to another
name an example of a bacterial, viral, fungal and protist disease (either plant or human)
bacteria - salmonella, gonorrhoea
virus - HIV, tobacco mosaic virus, measles
fungus - rose black spot, athlete’s foot
protist - malaria
name the six types of disease transmission
direct contact, sexual contact, water, air, food, vector
how do viruses reproduce?
they infect the host cell, replicate themselves inside the cell and burst out of the cell
how is HIV transmitted?
through sexual contact or sharing bodily fluids e.g. sharing a needle
how can malaria be prevented?
preventing mosquitoes from breeding, using mosquito nets to avoid being bitten
what is a symptom of rose black spot?
purple/black spots on leaves, whihc often turn yellow and drop off
how is salmonella transmitted?
food prepared in unhygenic conditions
what are the symptoms of salmonella?
fever, diarrhoea, abdominal cramps and vomiting
what are chickens in the UK vaccinated against?
salmonella
what does HIV eventually develop into?
AIDS
how is measles transmitted?
through the air in droplets when an infected person sneezes
what are the symptoms of measles?
fever and red rash
what are the symptoms of TMV?
“mosaic” pattern of discoloration on the leaves which affects growth of plant due to lack of photosynthesis
what are the symptoms of gonorrhoea?
burning pain when urinating and yellow/green discharge from penis/vagina
how is gonorrhoea prevented?
use barrier contraception such as condoms
how can bacterial diseases be treated?
using an antibiotic
what is a vector?
an organism that spreads a pathogen from one host ot another but does not get sick
name 3 non-specific human defense systems
mucus in trachea and bronchi (traps pathogens), skin (covers body and produces antimicrobial substances), cilia in trachea and bronchi (move mucus to the throat to be swallowed), stomach acid (kills pathogens)
define “pathogen”
a microorganism that causes disease and harm
what do phagocytes do and what is this process called?
Phagocytes engulf pathogens and break them down to destroy them. This is called phagocytosis
what do bacteria release that make us feel ill?
toxins
how do viruses damamge the body?
they reproduct inside cells and later burst out of them, which leads to cell damage
how do lymphocytes detect pathogens?
they detect the pathogen’s antigens (proteins on the surface of the pathogen) and they recognise that they are foreign
what do lymphocytes do?
release antibodies and antitoxins
what do antibodies do?
make the pathogens clump together so they can be engulfed more easily by the phagocytes
what do antitoxins do?
neutralise toxins
why are lymphocytes called “specific”?
the antigens and antitoxins they produce are highly specific to the antigen on a pathogen
what is a vaccine?
a substance containing the inactive form of a pathogen which can be injected into the body to trigger an immune response
how does the body react to a vaccine? what happens if the body is exposed to the same pathogen again?
an immune response is triggered where white blood cells create antibodies complimentary to the pathogen. After a second exposure, the white blood cells react more quickly as memory cells remember the antibody created for the pathogen
what is herd immunity?
when the majority of a population are vaccinated against a disease, any outbreaks of the disease are contained because a majority of the population is immune to it
how do you treat rose black spot?
fungicides, removing and drestroying infected leaves
what is herd immunity?
when a high percentage of the population is vaccinated against a disease, outbreaks are contained because a majority of the population is immune to the disease
what is the difference between painkillers and antibiotics?
painkillers relieve the symptoms of a disease but they do not cure it. antibiotics kill the pathogens themselves and therefore cure the disease
can antibiotics cure viral infections?
no
what was the first antibiotic and who discovered it?
penicillin, discovered by Alexander Fleming
where did penicillin come from?
penicillium mould
why is it difficult to create antiviral drugs?
they might damage the host cell while killing the virus as viruses reproduce inside cells
what makes antibiotics less effective?
overuse, not taking the full prescribed course
what is a superbug?
bacteria that are more resistant to antibiotics due to gene mutations
what are two ways to culture bacteria?
colonies on agar plates and nutrient broth solution
what is the method for preparing agar plates for culturing bacteria?
step 1 - wipe down surface you will be doing the exteriment on, and sterilise any equipment
where does digitalis originate and what organ does it treat?
foxglove, it treats the heart
where does aspirin originate?
willow
what three things do new drugs have to be tested for?
efficacy, toxicity, dosage
what is the first stage of preclinical drug testing?
the drug is tested on human skin cells to check for efficacy and possible side effects
what is the second stage of preclinical drug testing?
the drug is tested on animals to check for side effects
what is involved in human clinical trials?
first, the drug is given to healthy human volunteers, and then to people with the disease. Initially small doses of the drug are given, and this is gradually increased until the optimum dosage is found.
