Topic 3.3 Immunology & Disease Flashcards
Disease - The body as a host:
a) Define INFECTION
b) What are ‘pathogens’?
c) Cholera is cause by what bacterium who is Gram _______ and is _________-shaped?
d) Can this bacteria reproduce outside as well as inside?
e) Cholera is described as being ENDEMIC. Explain…
f) People get contaminated HOW? Some people become carriers/referred to as disease reservoirs - explain both terms.
g) The bacteria produce TOXINS - Define properly what a TOXIN means. What do they impact if contracted by another individual?
h) Explain how the toxin wreaks hovok on the body…Where specifically, and what specifically is impacted? Explain the biology behind the symptoms of cholera (think about osmosis).
a) All groups of organisms suffer from INFECTION and disease. Infection is defined as a transmissible disease often aquired by inhalation, ingestion or physical contact in general (abiotic and biotic features of our surroundings).
b) Pathogens (an infectious microorganism or agent - agents refers to viruses and 4 other groups).
c) Cholera - Caused by the GRAM -VE bacteria, comma-shaped Vibrio cholerae.
d) Cholera - Can only reproduce when it’s inside its human host.
e) Cholera - It’s an endemic disease which means that it’s always present in low levels in a given area.
f) Cholera - People get contaminated through food or water. They (the people) become carriers (this means that they themselves show no symptoms but can infect others, essentially they becomes reservoirs of disease (that means that they host the pathogen in the long-term with few or NO symptoms and they are a potenital for a disease to outbreak…).
g) Cholera - The Vibrio chloarae bacteria produce TOXINS (toxins are small molecules that are made by cells that cause disease following contact or absorbtion by other individual. Toxins often impact macromolecules - i.e. enzymes, cell surface receptors…
h) Cholera - The Vibrio cholarea bacteria produce toxins in the SMALL intestin. Those toxins then impact the chlorine channel proteins called CFTR. Water and many ions (Cl-, Na+, K+ and HCO3-) aren’t absorbed into the blood! The patient then experiences watery diarrhoea. Dehydration is a result of this, blood pressure falls. Fatality is high. The toxin produced enters epithelial cells via endocytosis. Loss of Cl- and Na+ ions occurs. Therefore, the lumen of the intestine has a very LOW water potential which leads to water moving osmotically from the intestine’s epithlial cells OUT through the partially permeable membrane! This is what causes the diarrhoea.
i) Good hygiene and sanitation are key. Better sewage and waste water treatment are key. Safe food and water handling are key. Washing of hands is key. Patients are given water and ions to replenish those lost through diarrhoea. Either done through oral route or intravenous route.
Disease - TB:
a) TB is referred to as BACILLUS. Its shape is therefore…?
b) TB is named after tuburcules which are WHAT?
c) The WHAT possibly contain ________ that can be witnessed through X-rays. They contain CO2 and O2 in which the bacteria are able to do WHAT?
d) Two ways in which it can be transmitted. Give the two ways…
e)
a) TB is called by the rod shaped bacteria (which is therefore, bacillus bacterium, Microbacterium turberculosis. It is named after tuburcules, which are dead nodules of the cells in the lungs of people who get infected. Tubercules may contains cavities that can be witnessed via an X-ray. These cavities contain oxygen and CO2 in which the bacteria reproduce at high rates!
Aerosol transmission - inhalation of the bacteria-laden droplets (i.e. droplets that have the bacteria on them) from the coughs of people with TB.
