Respiratory System Flashcards
what host defences protect us from respiratory diseases
saliva, lymphoid tissue eg tonsils, alveolar macrophages
give an example of a disease causing sinusitis and how does it work
adenovirus, damages adhesions to cells, allows it to get through to mucosa and penetrate
give a virulence factor of streptococcus pyrogenes
exotoxins are haemolysis, break down blood cells, also protein m forming capsule
how does rheumatic fever result from strep pyrogenes
capsule is protective mechanism, form antibodies to this, but these are self reactive, attack sacrolemma of cardiac tissue, damages heart tissue
what is the difference between acute and chronic bronchitis
acute - happens over winter months due to virus
chronic - continuous cough for 3 months over 2 years
how does tb cause disease
has a thick capsule, macrophages engulf the bacteria, cannot lyse the capsule, so the bacteria continues to replicate inside the macrophages, giant cells form, if these liquify, the disease will spread in the body
what is pneumonia
inflammation of alveoli air sacs in lungs
how might pneumonia be acquired and what are pathogens are associated with disease
community - streptococcus pneumonia
hospital - staph aureus
what are 2 virulence factors of streptococcus pneumonia and how to they contribute to disease
pneumolysin - cleavage of proteins, allows adherence to alveoli cells, breaks down blood cells
capsulated - immune system can see bacteria but cannot get to it to attack it, chronic inflammatory disease
what are the treatments available for pneumonia
antibiotics - beta lactams, erythromycin
but resistance to these is increasing
so developing vaccine
how are drugs given by inhalation absorbed
powder which is topically by the airways, doesnt reach alveoli, is absorbed before then
how do bronchodilators aid respiratory disease
they act on beta 2 receptors as an agonist, opens up the airways, increase diameter, allows for better ventilation. or anticholinergic drugs block muscarinic nerve transmission to increase patency
how do anti-inflammatory’s aid respiratory disease
break down mucous being secreted, this prevents a blockage in the airway
what triggers an asthma attack
mast cell degranulation
what is chromoglycate used for
mast cell stabiliser
what drugs impair respiratory function
opiods and benzodiazepines
what are the 2 types of inhalers
Metre dosed inhaler - puffer, powder in air is pressed out an inhaled, but can go at a high velocity so more absorbed in mouth than airways
breath activated device - blow into the inhaler, activates the powder, this is then inhaled, much slower velocity, more likely to be absorbed in airways
what can be given with a puffer to improve efficacy
spacer - slows down velocity and allows for a higher concentration of dose to be given
what are the 2 types of beta agonist inhalers
short acting - salbutamol, immediately opens airways, good in asthma attack, but only lasts up to 4 hours
long acting - salmeterol, takes 2 hours to start working but lasts 12-15 hours, may have affects on heart so must be used with steroid inhaler
what is an anticholinergic inhaler available
ipratropium - grey, improves bronchodilation
what steroid inhalers can be used
brown - beclomethasone, different shades of brown for different concentrations, indications of how severe asthma is
orange - fluticosone, pink - mometasone
what inhalers would give an indication that the asthma is not too bad
blue only or green and brown
what inhalers would indicate more severe asthma
orange or pink with green
why are compound preparations useful
patients tend to stop taking brown inhaler as dont feel it is doing anything, take green only, compromise heart. so these can be put together in one inhaler to ensure patient receives both drugs
what are symptoms of obstructive disease
cough - either dry or producing
wheezing or stridor, pain or dysponea - distress whilst breathing
what are signs of obstructive disease
respiratory rate - normally 12-15 breaths per minute, but will be much higher if breathing is insufficient
chest movement, vocal resonance - speaking heard whilst sounding chest
what investigations can be done into obstructive disease
peak expiratory flow rate - maximum flow
forced expiratory flow - in one second
chest x-ray
what is vq mismatch
blockage in ventilation so not all alveoli receiving oxygen, blockage in arteries so not all alveoli being perfused, the alveoli being perfused are not being ventilated - results in no oxygen delivery to blood
what is asthma
a reversible airflow obstruction
what causes asthma
hyper-reactivity to un-harmful substance, e.g. cold air or exercise. causes mast cell degranulation resulting in inflammatory mediators - causes inflammation, mucous production and constriction of airway smooth muscle.
what do patients with asthma complain of
shortness of breath, wheezing and coughing
why can asthma be described as diurnal
when measuring PEFR this is lowering in the morning - ventilation is poor and more likely to have an attack. this then improves throughout the day.
why can asthma be described as biphasic
first phase - due to bronchial constriction of smooth muscle
second phase - inflammation and mucous production narrows airways due to inflammatory mediators
what drugs work at each phase
first phase - short acting beta agonist
second phase - corticosteroid
what drugs are indicitve of severe asthma
long acting beta agonist, theophyline, oral steroid or been admitted to hospital due to asthma attack
why are corticosteroids the most effective for preventing asthma
they attack the triad that causes obstruction - mucous production, inflammatory mediators and constriction
what is a copd
combination of obstructive disease and destructive disease, irreversible
what is destructive disease
emphysema - destruction of alveoli, the existing alveoli dilate to fill in space, results in reduced surface area for gas exchange - less oxygen into blood
what causes copd
smoking is biggest cause - pack years related to worse disease, lower fev
may be occupational related - asbestos, resulting in fibrosis
how is copd managed
bronchodilators and corticosteroids. or increasing oxygen delivery in severe copd
what is the importance in dentistry with copd and asthma
inhalers - increased candida infections
oxygen - need to get it 24 hours a day, including during treatment
what drives breathing in type 1 respiratory failure
hypercapnia - levels of carbon dioxide get too high
what drives breathing in type 2 respiratory failure
hypoxia. chronic poor breathing, levels of carbon dioxide have been high so desensitised to it, dont recognise high levels to stimulate breathing so its low levels of oxygen that drive breathing
