5 Infection of respiratory system Flashcards
Before reaching the lungs what does the upper respiratory tract do to air ?
- filters
- heats
- humidifies
list 5 cells of the nasal cavity
- ciliated epithelial
- basal epithelia
- M cells
- goblet cells
- dendritic cells
function of ciliated epithelial cells
transport of mucus
function of basal epithelia cells
Attaches the epithelium to basement membrane
function of M cells
antigen/pathogen sampling
mucosal immunity
function of goblet cells
mucin secretion
function of dendritic cells
antigen presenting cells
antigen processing
3 Functions of lower respiratory tract (LRT)?
- takes in air from URT
- absorbs oxygen
- releases carbon dioxide
components of URT ?
URT = upper respiratory tract
- sinuses
- pharynx
- larynx (above vocal cords)
Components of LRT ?
LRT = lower respiratory tract
- larynx (below vocal cords)
- trachea
- bronchi
- lungs
- diaphragm
List the approx 7 barriers that URT has for forign particles (including pathogens)
- nasal hair (filtering of dust, pollen etc.)
- Mucus
- Mucociliary clearance
- Surfactant proteins
- Microbiota
- Antimicrobial peptides
- Secretory IgA antibodies
URT has distinct …1.. structures with different …2.. cell types
- anatomical
- epithelial
URT provides ..1…. that are colonised by ..2… species (bacteria, fungi, viruses)
- micro-niches
- different microbial
Aerosal transmission of pathogens:
* pathogens in expiration
* enter resp tract of ..2.. individuals through …3…
- susceptible
- inhalation
3 ways pathogens enter resp tract during inhalation of susceptible individuals ?
- coughing
- sneezing
- vocalising (talking, singing, shouting)
Overview of aerosal transmission of pathogens include 3 phases, what are these phases ?
- generation and exhalation
- transport
- inhalation, deposition and infection
Which microorganisms travels the most furthest and least furthers metres ?
viruses, bacteria, mycelia, mycoplasma, yeasts, eukaryotic cells
- viruses = 0.05 - 0.1µm
- mycelia = 100 µm - several metres
Difference between aerosol and droplets with:
1. travel distance ?
2. float in air / fall to ground , time takes , can / can’t be inhaled
3. < or > µm
4. contaminating surfaces ?
A:
1. within and beyond 1 meter
2. float for hours & be inhaled
3. < 5 µm
4. no mention of contaminate surfaces
D:
1. less than 1 meter
2. fall to ground, under 5 seconds, can’t be inhaled
3. > 100 µn
4. can contaminates surfaces (fomites)
In the first few hours of life how much microbiota do neonates acquire ?
a wide range
Neonates acquire abundance of following microbiota in first few hours and first week of life , name 4 examples …
** Staphylococcus spp. e.g. S. epidermidis*
** Corynebacterium spp. e.g. C. accolens*
** Dolosigranulum spp.*
** Moraxella spp.*
Early presence of which 3 microbiota at 4-6 months of age correlates with respiratory health ?
- Corynebacterium spp
- Dolosigranulum spp
- Morexalla spp
Name some featal factors which influence the respiratory microbiome in neonates
- birth mode
- feeding type
- siblings
- daycare
- season
Name some maternal/environmental factors which influence the respiratory microbiome in neonates
- genetics
- vaccination
- infection
- antibiotics
- smoking
Colonisation of URT in early life:
- In first week to 2 months of life what colonisation occurs
hypo-pharynx
(lower part of throat right behind the larynx, entrance into the oesophagus)
name 3 bacteria which colonise the hypo-pharynx region during first week to 2 months of early life
- streptococcus pneumoniae
- staphylococcus aureus
- moraxella catarrhalis
Colonisation of URT in early life:
- from 3-6 months what colonisation occurs
nasal cavity
name some bacteria which colonise the nasal cavity during first 3-6 months of early life
- streptococcus
Colonisation of URT in early life:
- from 12 months > what colonisation occurs
nasal cavity
name some bacteria which colonise the nasal cavity during first 12 months > of early life
- corynebacterium
- bifidobacterium
- dolosigranulum
(Imagine a baby named ‘‘Cory” dancing on the sand that’s shaped like $ dollors $ and the baby has bifocal glasses)
Several species of bacteria that ..1.. the URT can , under certain …2…, lead to …3..
- colonise
- circumstances
- infection
List 7 bacteria species that can colonise the URT and lead to infection under certain circumstances
- Haemophilus influenzae type b
- Staphylococcus aureus
- Neisseria meningitidis
- Streptococcus penumoniae
- Streptococcus pyrogenes
- Streptococcus agalactiae
- Streptococcus anginosus
From some of the bacteria that colonise the URT which can lead to infection, which ones have protection with childhood vaccinations ?
- Haemophilus influenzae type b
- Streptococcus penumoniae
- Neisseria meningitidis
Name some common infections of URT
- sinusitis
- common cold
- epiglottitis
- laryngitis
- pharyngitis
[* nasopharyngitis ?]
What diagnosis are done for the infections of URT ?
- examinations of nose, ears, throat
- breathing (to determine if infection in LRT)
% of adult colds that are of unknown causative agent ?
20-30
Name 4 viruses that can cause common cold
- rhinoviruses
- coronaviruses
- parainfluenza virus
- respiratory syncytial virus
Bacteria that cuases epiglottitis ?
- haemophilus influenzae type b
- streptococcus pneumoniae
- streptococcus A, B, C
- staphylococcus aureus
Microbiome of LRT composed of … list 4 ?
- bacteria
- viruses
- bacteriophages
- fungi
In the microbiome of LRT what is not well characterised ?
- virome
- mycobiome
Give some examples of fungi found in the microbiome of the LRT [other examples]
- aspergillus
- penicillum
- candida
- eurotium
Some examples of natural defenses against infection in the lower respiratory tract (LRT) [might need to change ?]
- mucus membranes line the trachea, bronchi & bronchioles
- alveolar macrophages
- IgA within the mucus
- Lower respiratory tract generally lacks micro-organisms
LRT microbial populations primary enter the lungs through…?
mucosal dispersion and micro-aspiration from the URT
Lung microbiota is largely similar to …?
URT microbiome
main / likely source of microbiota in the following :
1. adults ?
2. children ?
- Oropharynx
- Oropharynx & nasopharynx
Gut-lung axis provides ..1.. communication between …2…
- bidirectional
- gut and lungs
Interactions of gut-lung axis ?
- host-microbe
- microbe-microbe
In the Gut-lung axis involves disruption of early life microbiome (e.g. antibiotics) is associate with what … ?
allergies and lung infections
Gut microbiota is implicated in ..1.. and …2… of systemic immunity
- regulation
- maintenance
4 types of respiratory defence mechanisms
- physical & physiological barriers
- mechanical
- immunological
- other
examples of defence mechanisms of physical & physiological barriers
- hair in nares (opening of nose)
- glottis
- tight junctions
- mucociliary apparatus
- alveolar surfactant
Physical & physiological barriers are impaired by ?
- cigarette smoke
- corrosive gases
Examples of mechanical defense mechanisms
- coughing
- sneezing
- reflex broncho-constriction
- gag reflex
Mechanical defence mechanism is impaired by ?
- anaesthesia
- neuromuscular disorders
- coma
Examples of immunological defence mechanisms ?
- innate immune activation (e.g. alveola macrophages)
- AMPs
- activation of complement
- APC
- lymphocyte recruitment
Immunological defence mechanism impaired by ?
alcohol, tobacco
Example of defence mechanism that isn’t physical & physiological barrier, mechanical, immunological
salivary enzymes
3 infections of the LRT ?
- bronchitis - bronchi inflammation
- bronchiolitis - bronchioles inflammation
- Pneumonia - lung parenchyma inflammation
3 features of Bronchitis
* self-limiting/not self limiting
* generally affected pathogen…
* diagnosis usually….
- self-limiting
- generally viral
- diagnosis usually clinical
3 features of bronchiolitis
* hosptilisations of which age group…
* virus causing it…
* majority of cases are …
- infant hospitalisations
- respiratory syncytial virus (RSV)
- majority of cases self-limiting
3 features of pneumonia (lung parenchyma inflammation)
* caused by ….
* classifed depeding on source of infection how ?
- caused by a range of pathogens
- community-acquired
- nosocomial (hospital-acquired)
