Diseases Flashcards
Diseases can be transmitted in many ways - name 2.
air, water, touch, animals, food.
Animal diseases can be spread by 5 main routes of transmission: direct contact (direct bodily fluid contact); inhalation of aerosols; ingestion; indirect transfer by fomites (contact with surfaces); or vector transmission (mosquito bites, etc).
How do people usually contract cholera?
drinking unclean water, eating food that has been in unclean water (i.e. shellfish) or eating food prepared by someone with cholera.
Name two symptoms of cholera.
diarrhoea, nausea, vomiting, cramps, irritability, fatigue, glassy or sunken eyes, dehydration, irregular heartbeat
Cholera can be mild or severe. How long would a mild case, where the patient is quickly diagnosed and treated to rehydrate last?
around 1 week.
What is the most common treatment for cholera
oral rehydration to replace fluids and electrolytes (salts).
Who was the Hungarian scientist (1818 - 1869) that helped to reduce the death rate of women from childbed fever?
Ignaz Semmelweis
What did Semmelweis notice about the difference between women who had delivered with the aid of midwives compared to those who had been delivered by obstetric physicians?
The rate of childbed fever and death was much higher in those delivered by physicians because physicians did not wash their hands between carryout autopsies and treating women in childbirth.
What recommendation did Semmelweis make to physicians aiding in childbirth?
mandatory hand washing, washing of medical instruments
What affect did his recommendations have on the mortality rate of women aided by physicians in childbirth?
It fell from 18% to 1%
What did many senior physicians was the cause for the reduction in mortality rates?
A new ventilation system, they believed infection was spread via ‘miasmas’.
Infectious diseases are caused by what?
Pathogens
define Pathogens
A pathogen is an organism that causes disease
Are all animal illnesses caused by pathogens?
No
Name two causes of illness in humans, not caused by pathogens.
vitamin deficiency, hereditary diseases, obesity, smoking
Give 2 examples of a chemical or physical defences the body uses to defend against pathogens
tears (enzymes destroy bacteria), ear wax (sticky physical - traps pathogens, though it is also acidic and antibacterial so also chemical), internal nose hairs (physical), stomach produces acid to kill pathogens in food (chemical), scabs cover wounds to physically protect.
Which blood cells form the immune system in humans?
white blood cells
where in the body are white blood cells formed?
the bone marrow
what is a leukocyte?
a white blood cell that fights disease and foreign objects in the body
approximately how many leukocytes are their in a microlitre of blood?
4,000 -11,000
Which cells constantly screen the blood, tissues and organs for signs of pathogens and foreign substances?
Leukocytes
define antigens.
An antigen is a molecule or molecular structure that may be present on the outside of a pathogen. This normally triggers an immune response
Name a type of Leukocyte
granulocytes, monocytes, and lymphocytes
What are phagocytes?
white blood cells that protect the body by ingesting harmful foreign particles, bacteria, and dead or dying cells.
Which cells trigger the immune response by releasing macrophages and dendritic cells into the blood?
phagocytes
which cells do phagocytes pass information to about the antigens they have digested?
Lymphocyctes
Which lymphocytes search the body for infected cells to kill, after phagocytes have identified the antigens?
T Cells
Which cells produce antibodies (proteins) to fight infection, using the antigen information gathered?
B-cells and helper T-cells
What is the purpose of a fever response to infection?
A warmer body makes it harder for bacteria and viruses to reproduce and spread.
What is the purpose of a swelling response to infection?
When body cells are damaged they release chemical which make fluid leak into surrounding tissues - swelling. This attracts phagocytes which consume invaders and damaged cells.
Fill in the missing words:
After F____ infection by a pathogen, the body R_______ how to make the appropriate A________. This ensures they can be made Q_____ in H_____ amounts should the same pathogen invade again.
After FIRST infection by a pathogen, the body REMEMBERS how to make the appropriate ANTIBODY. This ensures they can be made QUICKLY in HIGH amounts should the same pathogen invade again.
Vaccines contain D___ pathogens or live but W_______ pathogens or P____ of the pathogen.
Vaccines contain DEAD pathogens or live but WEAKENED pathogens or PART of the pathogen.
What happens when a vaccine is introduced into a body?
The leukocytes react as if it were a normal disease and build a mild antibody response and memory for future protection.
Name 2 common vaccines.
MMR, HPV, Flu, Diptheria, Tetanus, Polio
Which type of immunity is described here? A mother passes antibodies to her child via breastmilk.
Passive Immunity - antibodies created outside the body as passed to us.
Which type of immunity is described here? A vaccine is injected and the body creates antibodies in reaction.
Active Immunity - body created it’s own antibodies in response to infection or vaccine.
Who created the first vaccine against smallpox?
Edward Jenner
What non fatal disease did Jenner use to create his smallpox vaccine?
Cow Pox
Why did being infected with cow pox protect against small pox?
The diseases were similar enough for the cow pox antibodies to recognise and kill the small pox infection.
Why do we take antibiotics to treat some infections?
They can slow down or stop the growth of some bacteria.
Are antibiotics useful in fighting most viruses?
No
Which antibiotic come from Penicillum mould?
Penicillins
How have some bacteria managed to develop fairly widespread resistance to antibiotics?
When a course of antibiotics is started, the weak unresistant bacteria in the population die quickly, as the course continues the stronger, more resistant bacteria begin to die also. If the course of antibiotics is unsuccessful in killing all of the bacteria in the infection, the strong resistant bacteria are left and reproduce giving a large number of strong, resistant bacteria.
Bacteria reproduce by making clone (copies) of their cells. Sometimes these cells mutate. Will the mutated cells always be of similar strength and resistance to antibiotics?
No
What treatments can be offered when a bacterial infection is resistant to a specific antibiotic?
Other types antibiotics may be successful.
What do we call bacterial infections that are resistant to all antibiotics?
Superbugs (e.g. MRSE)
