Fighting disease Flashcards
Body features that prevent pathogens from entering the body
S…:
-acts as a …
-secretes … substances which … pathogens
H…:
-… particles that could contain …
M…:
-… particles that could … pathogens
-it is … where the pathogens are … by the … acid
T… and b…:
-secrete …
C…:
-trachea and … are lined with … which … the mucus up to the back of the … where it is …
S…:
-produces … acid
-… pathogens
Skin:
-acts as a barrier
-secretes antimicrobial substances which kill pathogens
Hair:
-traps particles that could contain pathogens
Mucus:
-trap particles that could contain pathogens
-it is swallowed where the pathogens are killed by the stomach acid
Trachea and bronchi:
-secrete mucus
Cilia:
-trachea and bronchi are lined with cilia which waft the mucus up to the back of the throat where it is swallowed
Stomach:
-produces hydrochloride acid
-kills pathogens
How does your body attack pathogens
-phagocytosis
-producing antibodies
-producing antitoxins
What is the most important part of your immune system
White blood cells
Phagocytosis
-white blood cells engulf foreign cells and digestive them
Producing antibodies
-every pathogen has … on its …
-some types of wbc with produce … called … when they come across a … antigen
-the antibodies … onto the i… cells so they can be … and destroyed by other … … …
-the … produced are … to that type of antigen
-… are then produced … and carried around the body
-if the person is … with the same … again then the wbc will rapidly … the antibodies to … it
-every pathogen has antigens on its surface
-some types of wbc with produce proteins called antibodies when they come across a foreign antigen
-the antibodies lock onto the invading cells so they can be found and destroyed by other wbc
-the antibodies produced are specific to that type of antigen
-antibodies are then produced rapidly and carried around the body
-if the person is infected with the same pathogen again then the wbc will rapidly produce the antibodies to kill it
What are white blood cells that produce antibodies known as
B-lymphocytes
What does producing antitoxins do
Counteracts toxins produced by invading bacteria
How do vaccinations work
-they involve … small amounts of … or inactive pathogens
-these carry a… which cause your body to produces a… to attack them
—>these pathogens are h…
-if the same … enter the … after that then … blood cells can rapidly …-produce antibodies to … the pathogen off
-they involve injecting small amounts of dead or inactive pathogens
-these carry antigens which cause your body to produces antibodies to attack them
—>these pathogens are harmless
-if the same pathogens enter the body after that then white blood cells can rapidly mass-produce antibodies to kill the pathogen off
Pros and cons of vaccination
Pros:
-have helped control lots of communicable diseases
-epidemics can be prevented if a large percentage of the population is vaccinated
Cons:
-vaccines don’t always work
-sometimes you can have a bad reaction to a vaccine eg swelling, fevers seizures
What are painkillers
Drugs that relieve pain, but don’t actually kill the pathogens, only reduce the symptoms
Eg of a painkiller
Aspirin
Eg of an antibiotic
Penicillin
What do antibiotics do
They kill or prevent the growth of bacteria causing the problem, without killing body cells
Why is it difficult to develop medicine to kill viruses
-viruses reproduce using your body cells
-this makes it hard to develop drugs that destroy just the virus without killing the body’s cells
How can bacteria become resistant to antibiotics
-bacteria can m…, causing it to become … to an antibiotic
-this means that when you treat the i… only the non-… bacteria will be k…, but the resistant bacteria will … and r…
—>causing the p… to i…
-this resistant bacteria can’t be treated by …
-bacteria can mutate, causing it to become resistant to an antibiotic
-this means that when you treat the infection only the non-resistant bacteria will be killed, but the resistant bacteria will survive and reproduce
—>causing the population to increase
-this resistant bacteria can’t be treated by antibiotics
How to slow down the rate that bacteria becomes resistant
-avoid the over-prescribing of antibiotics
-finish the whole course of antibiotics
Where does aspirin come from
Willow trees
Where does Digitalis come from
Fox gloves
How was penicillin found
He found that mould on the Petri dish was producing penicillin which killed bacteria
Three main stages of drug testing
- Testing in human cells and tissues
- Testing on live animals
- Testing on humans
What happens in preclinical testing
- Drugs are tested in human cells and tissues in the lab
- Testing drugs on live animals
—>this is to test for efficiency, find out toxicity and to find the best dosage
What happens in clinical trials
- The drug is tested on … volunteers
—>to make sure it doesn’t have any h… side e…
—>very low d… is given to start, which is gradually i… - If the results in … people are good then the drug is tested on people … from the …
—>the o… dose is found (most effective with the least … effects) - To test how well the drug works patients are split into … groups, 1 is given the drug and the other is given a …
—>this is so the d… can see the d… the drug makes
—>allows for p… effect - Double … trials are used where both the doctors and … don’t know who is r… what
—>this is so doctors can’t s… be influenced - The drug trials aren’t p… until they have been through p… review
- The drug is tested on healthy volunteers
—>to make sure it doesn’t have any harmful side effects
—>very low dosage is given to start, which is gradually increased - If the results in healthy people are good then the drug is tested on people suffering from the illness
—>the optimum dose is found (most effective with the least side effects) - To test how well the drug works patients are split into 2 groups, 1 is given the drug and the other is given a placebo
—>this is so the doctor can see the difference the drug makes
—>allows for placebo effect - Double blind trials are used where both the doctors and patients don’t know who is receiving what
—>this is so doctors can’t subconsciously be influenced - The drug trials aren’t published until they have been through peer review
What is the placebo effect
When the patient expects the treatment to work so they feel better, even though the treatment isn’t doing anything
What is a placebo
A substance like the drug being tested but it doesn’t do anything
