Session 3 - Innate Immmunity Flashcards
define the immune system
cells and organs that contribute to immune defences against infectious and non-infectious conditions
true or false: cancer is a type of non-infectious condtion
true
define infectious disease
when a pathogen succeeds in evading and overwhelming the hosts immune defences
what physical barriers are involved in the innate immune system
- skin
- musocus membranes
- bronchial cilia
what are the differences in the innate and adaptive immunity
Innate:
- fast
- lacks specificity
- lacks memory
- no change in intensity
- first line of defence
what type of innate immune cells activate the adaptive immunity
dendritic
what type of barriers are involved in the innate response
physical, physiochemical, chemical and biological
what do the barriers of the innate immunity aim to do
prevent pathogen entry and limit growth
what are the physiological barriers in the innate immunity
- diarrhoea: expels miscorbes
- vomiting
- coughing
- sneezing
what are the chemical barriers in the innate immunity
- low pH (skin, stomach and vagina)
- antimicrobial molecules
what are the biological barriers in the innate immunity
- normal flora
what is the normal flora
non pathogenic molecules (as long as they don’t change location) found in the body
where is normal flora found
- skin
- mouth/throat
- nasopharynx
- GI tract
- vagina
what are the advantages of the normal flora
competes with pathogens for attachment sites and resources
produce antimicrobial chemicals
synthesise vitamins
give examples of antimicrobial molecules
IgA, lysozymes, mucus and gastric acid
give examples of normal flora that inhabit the skin
- staphylococcus aureus
- staphylococcus epidermidis
give examples of normal flora what inhabit the nasopharynx
- streptococcus pneumonia
- Neisseria meningitidis
when are there problems with the normal flora
- when its displaced from its normal location to a sterile location
- when it overgrows and becomes pathogenic when the host is immunosuppressed
- when it is depleted by antibiotics
what causes the displacement of normal flora
- breaching the skin
- the fecal oral route
- fecal-perineal-urethral route
- poor dental hygiene
how can the skin be breached
IV lines, burns, surgery and injection drug users