Health, Disease, Defence Mechanisms And Treatments Flashcards
How does the skin prevent microorganisms entering the body
Barrier that stops microorganisms entering the body
How do mucous membranes stop microorganisms entering the body
The membranes in nose and respiratory system trap and expel microorganisms
How does clotting stop microorganisms entering the body
Closes wound quickly to form a barrier that stops microorganisms gaining entry (also prevents loss of blood)
What is a lymphocyte
A type of white blood cell that produces antibodies
What is an antigen
Distinctive marker on a microorganism that leads to the body producing specific antibodies
What is a antibody
Structure produced by lymphocytes that has a complimentary shape to antigens on a particular microorganism
How do antibodies produced by lymphocytes destroy microorganisms that have entered the body
The antibodies latch onto the antigen and immobilises the microorganisms and then stops them from spreading further in the body making it easier to destroy the microorganisms
What are memory lymphocytes
After an infection the body has produced memory lymphocytes that remain in the body for a long time- these therefore can respond quickly and produce antibodies faster if infected again by the same microorganisms
What does the clumping of microorganisms do
Stops them from spreading around the body therefore making them easier to destroy and leads to reduced symptoms in the patient
What happens once the microorganisms have been clumped together
Another type of white blood cell called phagocytes surrounds and engulfs the microorganisms and digests them, this process is called phagocytosis
What is the primary response
When an individual is infected by a disease are often ill for a few days before the antibody numbers are high enough to provide immunity
What is the secondary response
When someone has once been already infected by a disease and has produced memory lymphocytes that remain in the body for many years and therefore means they will produce antibodies very quickly to stop the individual catching the disease and a lot of the time the individual isn’t aware they have the same disease again as we may not show any symtoms
What is immunity
When antibody levels are high enough or produced quickly enough to prevent disease
What is active immunity
The type of immunity that produces antibodies to combat disease. This is slower but lasts longer than passive immunity
What is passive immunity
When you are injected with antibodies by for example a pharmacist. These are faster acting but last a shorter period of time than active immunity
What does passive immunity allow
Rapid treatment for very serious infections
What is a vaccination
The injection of dead or modified pathogens with purpose of producing antibody and memory lymphocytes in the blood for a certain disease.
Why might a booster vaccine be required
If one vaccination isn’t enough to have the sufficient amount of antibodies to be immunity level for a long period of time
What are two structural plant defence mechanisms to pathogens
Waxy cuticle- prevents microorganisms from entering the plant
Thick cell walls- protect cells by surrounding them
What is a chemical plant defence mechanism
Plants produce antimicrobial chemicals harmful to infectious microorganisms eg: mint, or poisonous chemicals that can defend against small animals eg: insects, and they discourage them the use of the plant as food
Who discovered the first antibiotic and when
Alexander Fleming discovered the first antibiotic, penicillin, in 1928
How did Fleming discover Pennicillin
- OBSERVED the bacteria couldn’t grow near a fungus on agar jelly
He then,
-CONCLUDED that something (a chemical) was spreading from the fungus and killing the bacteria
Fleming was unable to isolate the chemical responsible for killing the bacteria, but what scientists in later years found the chemical responsible
Florey and chain
Where are the microbes that make penicillin and their drugs grown
In large biodigesters or fermenters that create the perfect conditions for fungal growth
What are the 3 stages of making new medicines and drugs
Preclinical trials stage 1 (vitro testing)
Preclinical trails stage 2 (animal testing)
Clinical trails
What happens in preclinical trails stage 1
Testing on living cells and tissues in a laboratory
Initial trial and error process
Drugs are tested to see if they’re effective and that it doesn’t harm living cells
Allows testing before use on living organisms
What happens in preclinical trials stage 2
Testing on animals to check how they work on the whole organism
What are the benefits of preclinical testing stage 2
- avoids testing on humans
-can check for side effects in living organisms
What are the disadvantages of preclinical testing stage 2
- animals are different to humans so the drug may affect the animal differently when used in humans
-raises ethical issues
What do clinical trials involve
Testing on a small number of healthy human volunteers and then patients
What are clinical trials used to find out
- how effective the drug is at doing what it’s meant to do and finding the optimum dosage
- find the side effects of the drug if any
Why do new medicines have to be peer reviewed
Peer review is when other scientists of at least an equal standing the investigator scrutinise the new research and then provide detailed feedback and suggest refinements where appropriate to make sure the new drug is validated
What is a antibiotic
A chemical produced by fungi that kills bacteria
How can antibiotics be resisted
- some bacteria can mutate meaning their DNA changes and the bacteria develop new properties causing them to become resistant to antibiotics and therefore the antibiotics won’t work against this particular bacteria
What is a super bug
A bacterium that is resistant to most antibiotics, for example MRSA, superbugs are major problems in hospitals
What procedures can take place to reduce the incidence of superbugs
- don’t overuse antibiotics when not needed (eg: against viral diseases as antibiotics don’t help viruses)
-increase hygiene measures in hospitals eg: staff and visitors wash hands or use hand gels regularly
-isolating patients infected with superbugs
What is the aseptic technique used for
When working in the lab with bacteria and fungi it’s important to avoid contamination of the cultures used and the growth of unwanted pathogenic microorganisms
What’s the method when using the aseptic technique when transferring microorganisms
-pass a metal loop through flame of Bunsen burner
-allow loop to cool
- inoculation the microbes in the culture bottle (remove lid of culture bottle and glide loop on the surface of agar)
- replace the lid of the culture bottle to prevent contamination, when doing this sweep the neck or the bottle through the flame to kill any airborne microorganisms
-spread microbes over the surface of the agar in Petri dish by gently gliding the metal loop over the agars surface. Only open the Petri dish lid at an angle as it’s less likely for unwanted microbes to enter from the air
- the metal loop can then be heated again at a high temp to kill any microorganisms remaining on the loop are destroyed
- Petri dish should then be taped and then incubated in a oven at 25 degrees
- when carrying out the transfer ensure a Bunsen burner is close to where you are working as it provides a upward current or air that carries unwanted microbes in the air away thus avoiding contamination
- when the investigation is complete clean all work surfaces and hands and safely dispose of bacteria cultures by following your teachers instructions. Autoclaving will sterilise glass Petri dishes and culture bottles
What are non communicable diseases normally a consequence of
Inheriting a combination of genes that predispose us to developing some conditions like cancer or due to lifestyle factors or a combination of both
Why would poor diet effect our health
Too much sugar and saturated fat can lead to obesity
Why might lack of exercise effect out health
Less energy being used that taken in, leads to obesity
Why might overexposure of sun effect our health
UV radiation can cause mutations, leading to skin cancer
Alcohol can also effect our health why
Binge drinking leads to damage to the liver and affects foetal development during pregnancy
Smoking can also damage health, what substances in cigarette smoke harms us
Tar
Nicotine
Carbon monoxide
Why is tar harmful
Causes bronchitis (narrowing bronchi and bronchioles I’m lungs), emphysema (damage to alveoli, reducing SA for gas exchange) and lung cancer
Why is nicotine harmful
Addictive and affects heart rate
Why is carbon monoxide harmful
Combines with red blood cells to reduce the oxygen carrying capacity of blood
What are coronary arteries
Blood vessels that bring blood to heart
How does heart attack occur
-build up of cholesterol cause coronary artery to narrow
-causes blockage or clot
-blood carrying oxygen and glucose can therefore not reach heart muscle in affected areas
-heart can’t respire or produce energy, therefore muscle cells die and can’t contract causing heart attack
How does a stroke occur
Same as a heart attack except it’s blood vessels leading to the brain being blocked
Lifestyle factors that contribute to CVD
excess dietary fats
Smoking
Lack of exercise
Stress
Ways to treat CVD
Angioplasty and stents
Drugs such as statins and aspirin
What is angioplasty and stents
Angioplasty is a Medical technique involving the use of a balloon-like structures in to hold open diseased arteries so that stents (small like mesh structures) can be inserted in to keep blood vessels open.
What does statins do
Help reduce blood cholesterol
What does aspirin do
Thin blood to make it less sticky
What is cancer
Uncontrolled cell divisim
What is a benign cancer tumour
One that doesn’t spread through the body and often have a distinct boundary
What is a malignant cancer tumour
These can spread in the body
How to protect skin from over exposure to the sun
Cover up
Use high factor sun screen
Avoid sun at hottest part of day
Why shouldn’t u smoke to prevent cancer
As tar causes lung cancer
Why should u get a HPV vaccine in order to not get cancer
HPV virus is linked to cervical cancer so you must get a vaccine
What are screenings
Programmes designed to detect cancer at the earliest stage before cancer becomes malignant and spreads. Increases chances of treatment being successful
3 methods of removing cancer
Surgery (physically removing tumour)
Radiotherapy (using X-rays or other radiation to kill cancer cells)
Chemotherapy (use drugs to kill cancer cells)
Advantages and disadvantages of surgery to remove cancer
Adv: few side effects
Dis: won’t work if cancer has spread or in inaccessible parts of body
Advantages and disadvantages of radiotherapy
Adv: can target cancer sites deep in body accurately
Dis: will damage healthy cells as well as cancer cells
Advantages and disadvantages of chemotherapy
Adv: can target cancer anywhere in body
Dis: “Broad brush” approach with significant side effects eg: nausea and hair loss
What is immunotherapy
A more recent cancer treatment, antibodies are injected into patient. Antibodies attach to cancer cells to help body’s immune system destroy cancer cells. It has fewer side effects than other forms of treatment
NHS cost of economic factors when treating diseases
Long stays means long stays in hospital giving them hospitality and food etc etc and expensive drugs and medicines may have to be used and highly trained specialist staff are required who require a salary of standard.
