CB5- Health, Disease And The Development Of Medicines Flashcards
What is health?
- a state of complete physical, mental and social well-being, not just the absorption illness or disease
- for example even if someone is physically fit- eating well, free from disease, getting regular physical activity- they may still be unhealthy due to poor mental health or social isolation
What is disease?
- a condition where part of an organism does not function correctly, this is not the result of injury
- a disease can either be communicable- spread between individuals by pathogens or they can be non-communicable- diseases that cannot be transmitted between individuals and are caused by faulty genes or lifestyle
What is a communicable disease?
- diseases that can be spread between individuals
- they are caused by pathogens
What is a non communicable disease?
- non communicable diseases cannot be transmitted between individuals
- they are caused by problems in the body like faulty genes or lifestyle.
How are diseases correlated with one another?
- if you are affected by one disease, it can make you more susceptible to others, this is because:
- one disease can damage the immune system, making it easier for other pathogens to cause diseases
- diseases can also damage the body’s natural barriers, and defences, allowing pathogens to get into the body more easily
- a disease scan stop an organ system from working effectively, making other diseases more likely to occur
What are pathogens?
- pathogens are micro organisms such as viruses, bacteria, fungi and protists that cause communicable diseases
Describe the disease cholera.
- the pathogen that causes cholera is a bacterium
- it is a communicable disease
- the symptoms/effects are diarrhoea
- it spreads via contaminated water
- to reduce cholera there must be clean water supplies
Describe the disease tuberculosis.
- tuberculosis is caused by bacterium
- it is a communicable disease
- symptoms include coughing blood specks as it infects and damages lungs
- it spreads via air and wind by and infected coughs
- to reduce TB infected people should avoid crowded areas, practice good hygiene, live in well ventilated living spaces
Describe the disease malaria.
- malaria is caused by a protist
- it is a communicable disease
- symptoms and effects include fevers and tiredness, as red blood cells are minimised in size and amount
- it spreads via mosquitos which are vectors(carriers) that will spread the protists onto humans, without being affected itself
- to reduce malaria use mosquito nets and insect repellant to prevent bites
Describe chalara ash dieback.
- caused by fungus
- communicable disease between ash trees
- the symptoms and effects are early dying, loss of leaves and wounds on bark
- it is an airborne disease carried by the wind but also can be spread during the transportation of infected ash trees
- to prevent this you must remove young infected trees, restrict the import and movement of infected trees.
What are STI’s and what are some important ones you need to know?
- sexually transmitted infections
- spread through sexual intercourse and contact
- notable STI’s include chlamydia and HIV
What is HIV?
- HIV is a sexually transmitted virus
- it is the human immunodeficiency virus
- it infects and kills white blood cells which can affect the immune system and prevent it from functioning properly, since their immune systems can prevent them from secondary infections people with HIV often develop AIDS.
- it is spread via infected bodily fluids (blood, semen, vaginal fluids)
- to prevent aids: use condoms, drug users shouldn’t share needles, medication can reduce the risk, screening allows early diagnosis for treatment
What is AIDS?
- AIDS is a disease caused by HIV. HIV damages the immune system, causing it not to be able to defend against secondary infections
- the infected persons immune system deteriorates and eventually fails, this causes the person to be very vulnerable to other pathogens which could infect them
- this means that even mere colds can have a severe effect on people with HIV
What is chlamydia?
- chlamydia is a sexually transmitted bacterial infection
- while it’s a bacterium, it behaves in a similar way to a virus by infecting a host cell and reproducing
- it can result in infertility in both men and women
- it is also caused by bodily fluid contact
- to prevent: wear a condom, get regular screening for early treatment, avoid sexual contact- abstinence
What is a physical barrier? +examples
- skin is the main example of a physical barrier, pathogens could only cross via vectors or wounds since it is difficult to get past it.
- if there were to be a wound however, blood platelets would cause the blood to clot and the opening, preventing excessive bleeding and pathogens from entering.
- mucus in the nose and airways in the lungs trap particles that contain pathogens
- cilia- also lines airways and are hairlike structures that will take mucus(with the trapped pathogens) to the back of the throat where it can be swallowed.
What is a chemical barrier?+examples
- hydrochloric acid in the stomach can kill pathogens that have been swallowed while being trapped in mucus
- lysozyme is an enzyme that that breaks down the cell walls of some bacterium’s and are able to kill them, they are secreted in tears, saliva and mucus, it is a chemical defence because it reacts with substances in the pathogen in order to kill them
What is the function of the immune system?
- if pathogens were to enter the body after overcoming all the physical and chemical barriers, then the immune system would become active and destroy the pathogens.
What is the immune system made up of?
- white blood cells- which are able to detect pathogens and kill them
- white blood cells known as lymphocytes are greatly involved in the immune response as they produce anti bodies that are able to bind onto the anti gens on pathogeths and kill them
- phagocytes also play a crucial role as they are non-specific white blood cells which trap, engulf and digest pathogens
- phagocytosis is often the first process to happen as it is non specific to the pathogen, then (it’s a general defence mechanism) and then lymphocytes are used for highly specific targeted responses.
What is the function of lymphocytes?
- white blood cells known as lymphocytes are greatly involved in the immune response
All pathogens have antigens on their surfaces, when lymphocytes come across these pathogens they are able to produce antibodies which are complimentary to these antigens, the anti bodies can match its surface shape to the antigens, and then bind onto them. - the lymphocyte is now activated and can divide rapidly to produce lots of other identical lymphocytes with the same antibody to now destroy the pathogens all throughout the body
- after all the pathogens are killed some lymphocytes with anti bodies that still match the former antigens of the pathogen remain in the blood and are known as MEMORY LYMPHOCYTES
What is the significance of memory lymphocytes?
- since memory lymphocytes remain in the blood, containing the same antibody needed to fight a specific pathogen, if it were to enter the body again the memory lymphocytes will have a faster secondary response, making you immune to that specific pathogen
- the secondary response may be so fast that it comes into action before symptoms are even present
What is phagocytosis?
- phagocytosis is when phagocytes are able to detect pathogens in the body and engulf and digest them
- phagocytosis is non specific so it is a general mechanism of defence against all pathogens
What is immunisation?
- this is when people can get vaccinated against some diseases to avoid getting I’ll
- this involved infecting a weaker, inactive version of disease, usually some weak pathogens that will not cause a huge effect
- even though these pathogens are not active, they will still carry antigens so your body will formulate a response with lymphocytes which will produce antibodies to kill the pathogen
- the antibodies from this will remain in the blood as memory lymphocytes so if the same type of disease/pathogen were to enter the body again, the body would have a very fast immune response, stopping the illness
What are antibiotics and how do they work?
- used to treat bacterial infections
- it does this by inhibiting processed in bacterial cells, but not the host organisms
- it can do by inhibiting the bacterial cell wall, this will have no effect on the host organism as animal cells do not have cell walls
- some issues with antibiotics can be antibiotic resistance
Are antibiotics effective against viruses?
- antibiotics don’t destroy viruses as they attach themselves to host cells and it would be very difficult to just destroy the virus without destroying the host cell