Immunity Flashcards
Bacterial Structural features
Cell Wall
No membrane bounding organelles
Rings of DNA
Virus structural features
Flagellum
Protein spikes
Protein sheath
Contains RNA
Difference between bacteria and a Virus
Virus can infect widespread whereas bacteria is localised
Virus is non-living whereas bacteria is a unicellular living organism
Bacteria can be beneficial whereas viruses cannot be beneficial
Contact transmission of pathogens
Indirect contact - touching something an infected person has touched
Direct contact - touching an infected person
EXAMPLE - STIs
Transfer of bodily fluids of pathogens
Bodily fluids come into contact with mucous membranes of an uninfected person so the pathogen can enter the body
EXAMPLE - HIV
Transfer of pathogens via droplets
Droplets of moisture containing pathogen emitted when sneezing or coughing can be breathed in by another or settle on food
EXAMPLE - Measles
Transmission of pathogens via ingestion
Consumption of food or drink contaminated with pathogen allowing it to enter via the digestive tract
EXAMPLE - Salmonella
Transmission of pathogen via airborne transmission
When moisture in exhaled droplets evaporates, some bacteria and viruses remain viable which cause infection when inhaled
Transmission of pathogens by vectors
Transfer of pathogen via an animal
EXAMPLE - Malaria
Skin as external defence
Impervious barrier prevents entry
Secrete sebum containing antibacterial substances
Sweat glands produce lysozyme
Cilia as an external defence
Beating motion moves mucous upwards where it can be expelled
Hair as an external defence
Traps particles
Mucous as an external defence
Traps microogranisms
Acids as an external defence
In stomach, kill pathogens which have been ingested
In vagina which reduce growth of microorganisms
Lysozyme as an external defence
Enzymes that kill bacteria
Flushing action as an external defence
Urine flowing prevents bacterial growth
Cerumen as an external defence
Earwax, protects outer ear against infections