Health, Disease, Defence Mechanisms And Treatments Flashcards
What is a communicable disease?
A disease that is passed from one person to the other, so is described as being infectious eg. Common cold
What is a non-communicable disease?
A disease that is not passed from one person to another. They are usually a consequence of inheriting a combination of genes that increase your chance of developing a condition eg. Cancer or due to lifestyle eg. Type 2 Diabetes
Living things are called organisms. Some organisms are very small and we need powerful microscopes to see them. What are organisms like that called?
Microorganisms or microbes
How are microbes/microorganisms dangerous?
They can gain entry to the body causing illness.
What are the three main types of microbes that can cause infection?
Bacteria
Virus
Fungi
What are microbes that cause disease known as?
Pathogens
What type of microbe is chlamydia?
How is it spread?
Bacterium
Sexual contact
How can chlamydia be controlled?
Using condom reduces risk
Treatment by antibiotics
What type of microbe is salmonella/food poisoning?
How is it spread?
Bacterium
Contaminated food
How can salmonella/food poisoning be controlled?
Cook food thoroughly and not mixing cooked and uncooked food reduces spread.
Treatment by antibiotics.
What type of microbe is tuberculosis?
How is it spread?
Bacterium
Airborne
How can tuberculosis be controlled?
BCG vaccination
Treated with drugs, including antibiotics
What type of microbe is HIV leading to aids?
How is it spread?
Virus
Exchange of fluids during sex
Infected blood
How can HIV leading to aids be controlled?
Using condom reduces risk
Drug addicts should avoid sharing needles
No cure
Currently controlled by drugs
What type of microbe is cold/flu?
How is it spread?
Virus
Airborne
How can cold and flu be controlled?
Flu vaccination for targeted groups
What type of microbe is HPV (Human Papilloma Virus)?
How can it spread?
Virus
Sexual contact
How can HPV be controlled?
HPV vaccination offered to 12-13 year old girls to protect against developing cervical cancer.
What type of microbe is MMR (Measles, Mumps and Rubella)?
How does it spread?
Virus
Airborne for all
Contact for Rubella
How can MMR be controlled?
Prevented by MMR vaccine.
What type of microbe is athletes foot?
How does it spread?
Fungus
Contact
How can athletes foot be controlled?
Reduce risk by avoiding contact where spores are present eg. Changing rooms, swimming pools.
What type of microbe is Potato Blight?
How does it spread?
Fungus
Spore spread in the air from plant to plant, particularly in humid/warm conditions.
How can Potato Blight be controlled?
Crop rotation and spraying plants with a fungicide
What are the bodies 3 defence merchandises against communicable diseases?
Skin: acts as a barrier to microorganisms
Mucus membrane: they line the opening in the body (nose and respiratory system) and trap the microorganisms to stop them from going any further
Blood clotting: stops blood escaping and acts as a barrier against infection as it stops microorganisms getting in the bloodstream
What is an antigen?
An antigen is a specific marker on a microorganism that leads to the body producing antibodies
What is an antibody?
An antibody is a structure produced by lymphocytes that has a complementary shape to antigens on a particular microorganism and that can attach to the antigens. They are made by our body.
When a microorganism enters the body, the white blood cells have 2 main ways of killing them, what are they?
- Lymphocytes produce antibodies
- Phagocytes engulf and digest the microorganism through phagocytosis
What do lymphocytes do when microbes enter the body?
• invading microorganism have chemicals called antigens on their surface
• lymphocytes recognise these antigens as foreign
• lymphocytes produce antibodies to attack these antigens
• these antibodies have a shape that is complementary to the shape of the antigens on the microorganisms
• the antibodies attach onto the antigen on the microorganism
• antibodies cause the microorganism to clump together and become immobilised
• clumps of microorganism are then easily destroyed by other white blood cells called phagocytes in the process phagocytosis where they are engulfed and digested. The clumping reduces the spread of microorganisms around the body, which means there are less symptoms for the patient
• the above describes a primary response
What happens after the body is infected?
• after an infection, the body produces memory lymphocytes that remain in the blood for a long period of time, this means if the body is infected with the same microorganism it will produce the correct antibodies quickly to fight of the infection
•this is a secondary immune response, very often you may not even have symptoms to show you have the disease
What do phagocytes do once lymphocytes have caused the microbes to clump together?
- The phagocyte will surround the microorganism
- It engulfs (eats) it
- Chemicals (enzymes) inside the phagocyte digest the microorganism and destroy it
What does it mean if someone is immune?
If someone is immune this means that their antibody levels are high enough to combat the microorganism should it gain entry to their body again, this is a primary response.
What do memory lymphocytes do?
Every time a body is infected with a microbe, memory lymphocytes are produced.
If the body is infected with the same microorganism, the memory lymphocytes will produce antibodies quickly and stop the individual catching the disease again. This is known as a secondary response.
What is active immunity?
Give examples.
Active immunity is where the BODY produced the antibodies used to combat the infectious microorganism.
This is either from getting the infection or receiving a vaccination.
What are the characteristics of active immunity?
Slow acting
Lasts a very long time
What is a vaccination?
Dead or small doses of pathogens are injected into the body. This produces raised antibody levels in the blood and causes production of memory lymphocytes.
What is passive immunity?
Passive immunity is where antibodies from another source are injected into the body.
Eg. Antibiotics
What are the characteristics of passive immunity?
Fast acting
Last for a short period of time
Where can antibodies be passed across?
Placenta
Breast milk
What is the effect of infection on antibody level?
The level of antibody rise slowly in response to microbe infection
After a period of time the antibodies reach a level that is high enough to fight the infection and allow the person to recover from the illness
What is the effect of passive immunity on antibody level?
Passive immunity is the use of ready-made antibodies that are injected into the body.
They act very quickly but are short lasting as they are not produced by the body.
What effect does primary and secondary response have on antibody levels?
The secondary response both produces antibodies more quickly and also produces many more antibodies than the primary response. This is because memory cells have already met the microorganism and can produce the antibodies much quicker.
What does a vaccination involve?
The use of dead or weakened pathogens that are injected into the body.
The dead microorganisms still have the antigens on their surfaces causing the body to produce antibodies at a high enough level to prevent the individual becoming ill.
The process is the exact same as having had the disease only you do not get ill first.
What are the characteristics of a vaccine?
It is a form of active immunity so slow to act but long lasting
After getting a vaccine, what do we need to ensure we remain healthy for a long period of time?
A second vaccination called a follow-up booster.
