Respiratory System

Question 1

what host defences protect us from respiratory diseases

Answer 1

saliva, lymphoid tissue eg tonsils, alveolar macrophages

Question 2

give an example of a disease causing sinusitis and how does it work

Answer 2

adenovirus, damages adhesions to cells, allows it to get through to mucosa and penetrate

Question 3

give a virulence factor of streptococcus pyrogenes

Answer 3

exotoxins are haemolysis, break down blood cells, also protein m forming capsule

Question 4

how does rheumatic fever result from strep pyrogenes

Answer 4

capsule is protective mechanism, form antibodies to this, but these are self reactive, attack sacrolemma of cardiac tissue, damages heart tissue

Question 5

what is the difference between acute and chronic bronchitis

Answer 5

acute - happens over winter months due to virus

chronic - continuous cough for 3 months over 2 years

Question 6

how does tb cause disease

Answer 6

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

Question 7

what is pneumonia

Answer 7

inflammation of alveoli air sacs in lungs

Question 8

how might pneumonia be acquired and what are pathogens are associated with disease

Answer 8

community - streptococcus pneumonia

hospital - staph aureus

Question 9

what are 2 virulence factors of streptococcus pneumonia and how to they contribute to disease

Answer 9

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

Question 10

what are the treatments available for pneumonia

Answer 10

antibiotics - beta lactams, erythromycin
but resistance to these is increasing
so developing vaccine

Question 11

how are drugs given by inhalation absorbed

Answer 11

powder which is topically by the airways, doesnt reach alveoli, is absorbed before then

Question 12

how do bronchodilators aid respiratory disease

Answer 12

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

Question 13

how do anti-inflammatory’s aid respiratory disease

Answer 13

break down mucous being secreted, this prevents a blockage in the airway

Question 14

what triggers an asthma attack

Answer 14

mast cell degranulation

Question 15

what is chromoglycate used for

Answer 15

mast cell stabiliser

Question 16

what drugs impair respiratory function

Answer 16

opiods and benzodiazepines

Question 17

what are the 2 types of inhalers

Answer 17

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

Question 18

what can be given with a puffer to improve efficacy

Answer 18

spacer - slows down velocity and allows for a higher concentration of dose to be given

Question 19

what are the 2 types of beta agonist inhalers

Answer 19

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

Question 20

what is an anticholinergic inhaler available

Answer 20

ipratropium - grey, improves bronchodilation

Question 21

what steroid inhalers can be used

Answer 21

brown - beclomethasone, different shades of brown for different concentrations, indications of how severe asthma is
orange - fluticosone, pink - mometasone

Question 22

what inhalers would give an indication that the asthma is not too bad

Answer 22

blue only or green and brown

Question 23

what inhalers would indicate more severe asthma

Answer 23

orange or pink with green

Question 24

why are compound preparations useful

Answer 24

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

Question 25

what are symptoms of obstructive disease

Answer 25

cough - either dry or producing

wheezing or stridor, pain or dysponea - distress whilst breathing

Question 26

what are signs of obstructive disease

Answer 26

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

Question 27

what investigations can be done into obstructive disease

Answer 27

peak expiratory flow rate - maximum flow
forced expiratory flow - in one second
chest x-ray

Question 28

what is vq mismatch

Answer 28

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

Question 29

what is asthma

Answer 29

a reversible airflow obstruction

Question 30

what causes asthma

Answer 30

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.

Question 31

what do patients with asthma complain of

Answer 31

shortness of breath, wheezing and coughing

Question 32

why can asthma be described as diurnal

Answer 32

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.

Question 33

why can asthma be described as biphasic

Answer 33

first phase - due to bronchial constriction of smooth muscle

second phase - inflammation and mucous production narrows airways due to inflammatory mediators

Question 34

what drugs work at each phase

Answer 34

first phase - short acting beta agonist

second phase - corticosteroid

Question 35

what drugs are indicitve of severe asthma

Answer 35

long acting beta agonist, theophyline, oral steroid or been admitted to hospital due to asthma attack

Question 36

why are corticosteroids the most effective for preventing asthma

Answer 36

they attack the triad that causes obstruction - mucous production, inflammatory mediators and constriction

Question 37

what is a copd

Answer 37

combination of obstructive disease and destructive disease, irreversible

Question 38

what is destructive disease

Answer 38

emphysema - destruction of alveoli, the existing alveoli dilate to fill in space, results in reduced surface area for gas exchange - less oxygen into blood

Question 39

what causes copd

Answer 39

smoking is biggest cause - pack years related to worse disease, lower fev
may be occupational related - asbestos, resulting in fibrosis

Question 40

how is copd managed

Answer 40

bronchodilators and corticosteroids. or increasing oxygen delivery in severe copd

Question 41

what is the importance in dentistry with copd and asthma

Answer 41

inhalers - increased candida infections

oxygen - need to get it 24 hours a day, including during treatment

Question 42

what drives breathing in type 1 respiratory failure

Answer 42

hypercapnia - levels of carbon dioxide get too high

Question 43

what drives breathing in type 2 respiratory failure

Answer 43

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