Topic 6 -4 Flashcards
(13 cards)
What may cause diseases in humans?
Bacteria
Bacteria can invade and destroy host tissues, often producing damaging toxins.
What are the two types of toxins produced by bacteria?
Exotoxins and endotoxins
Exotoxins are released into body fluids, while endotoxins are found in the cell walls of bacteria.
How do bacteria gain entry to the body?
Through wounds, intestines, and lungs
Natural body openings also serve as vulnerable entry points.
How are bacteria transmitted between individuals?
By direct contact, droplets in the air, food or water, or vectors
Bacteria are numerous and small, facilitating their transmission.
What are exotoxins?
Molecules produced by bacteria released outside the bacterial cell
They are spread in blood or body fluids and affect host cells.
What is a significant effect of Staphylococcus aureus exotoxins?
Overstimulation of the non-specific immune system, leading to toxic shock
This inflammatory response can be fatal.
What are endotoxins?
Lipopolysaccharides in the membranes of Gram negative bacteria
They have toxic effects and may complicate treatment.
What happens when endotoxins are released?
They cause local effects at the site of infection
For example, in Salmonella spp., they cause inflammation of the gut lining.
What does Mycobacterium tuberculosis cause?
Tuberculosis (TB)
This bacterium infects the lungs and forms tubercles.
How does Mycobacterium tuberculosis survive inside host cells?
By forming a resistant waxy coat
This protects it from the immune system.
What are tubercles?
Growths formed by Mycobacterium tuberculosis inside lung tissue
They protect the bacterium from the immune system.
True or False: Endotoxins have effects that are systemic and widespread.
False
Endotoxins typically have local effects at the site of infection.
Fill in the blank: Exotoxins can lead to _______ if the infection is in the intestine.
Vomiting
Other effects include damage to red blood cells.
