week 5

Question 1

where does Usual interstitial pneumonitis predominantly affect

Answer 1

UIP classically has a basal predominance.

Question 2

what will biopsy of classic chin lesions of sarcoidosis, erythema nodosum show

Answer 2

inflammatory changes, not granulomas

Question 3

does sarcoidosis feature caseating granulomas

Answer 3

sarcoidosis is a granulomatous disease, but these granulomas rarely caseate (caseous means “cheeselike!” A graphic description of what this particular type of tissue necrosis looks like). Compare this to TB, of which a hallmark feature is the caseating granuloma.

Question 4

what may the value of PaCO2 be in type 1 respiratory failure

Answer 4

type 1 respiratory failure is more common than type 2, and results from a failure of oxygenation only (type 1 = problem with 1 gas, type 2 = problem with 2 gases). As hyperventilation often occurs as a compensatory mechanism, this may result in more CO2 being blown off (remember CO2 is highly soluble) and therefore the PaCO2 can be low.

Question 5

what is diffuse alveolar damage

Answer 5

diffuse alveolar damage results from acute lung injury/inflammation. This includes chemical injury, respiratory viruses (including covid), drug effects, major trauma, etc…

Question 6

where are the embryonic lung buds derived from

Answer 6

the foregut

Question 7

what is narcolepsy associated with

Answer 7

rapid onset of REM sleep, and hallucinations at the time of falling asleep and/or waking.

Question 8

what does pulmonary hypertension in chronic respiratory disease result from

Answer 8

chronic hypoxia. Hypoxia triggers a reflex constriction of pulmonary vessels, and this constriction increases the vascular resistance and therefore the pressure of the pulmonary circulation.

Question 9

where does hypersensitivity pneumonitis tend to begin

Answer 9

in a centriacinar pattern

Question 10

what can be said about the alveolar wall and capillaries in a healthy lung

Answer 10

in a healthy lung, the alveolar wall and the surrounding capillaries are in direct contact, to allow efficient gas diffusion and exchange.

Question 11

can idiopathic lung disease cause fimger clubbing

Answer 11

yes !!!

Question 12

what is chronic ventilatory failure exacerbated by

Answer 12

it is exacerbated by REM sleep. REM sleep is associated with paralysis of skeletal muscle (except the diaphragm), so ventilation relies on the diaphragm alone.

Question 13

what does bronchopneumonia cause

Answer 13

severe pneumonia may result in NO ventilation to the affected lung or a large part of it. Therefore any blood passing through this region will not be oxygenated before returning to the left side of the heart. Compare this with the V/Q mismatch of less extensive pneumonia, where alveoli are ventilated, but poorly.

Question 14

what chromosome is the CFTR mutation for CF on

Answer 14

chromosome 7

Question 15

why may abdominal muscles move down in inspiration of someone with chronic ventilatory disease

Answer 15

this is called paradoxical abdominal wall motion (paradoxical because normal movement of the abdominal wall is upwards and outwards during inspiration). This indicates diaphragmatic weakness, which is the underlying cause of the ventilatory failure.

Question 16

what is obstructive sleep apnoea associated with

Answer 16

increased road traffic accidents

Question 17

why should people with giant bulae in thei lungs not fly in planes

Answer 17

the pressure changes that occur during commercial air travel can cause the bulla to expand in size and cause tearing or air emboli, both of which could be fatal.

Question 18

can trachea oesophageal fistulas resolve without treatment

Answer 18

no, they require surgery

Question 19

what is myasthenia gravis associated with

Answer 19

myasthenia gravis is associated with thymus tumours. Anybody with a new diagnosis of MG will undergo investigation for thymus tumour, and many of these people will end up having surgery.

Question 20

what are given to mothers going into preterm labour

Answer 20

steroids stimulate surfactant production, so mothers who go into labour prematurely are given steroids to reduce the risk of the baby having respiratory distress syndrome.

Question 21

what pattern will pleural effusion give on spirometry

Answer 21

restrictive, as it reduces the volume available in the thoracic cavity for the lungs.

Question 22

how is continuous positive airway pressure used as a treatment for people with sleep apnoea

Answer 22

CPAP is delivered through an airtight mask that blows high pressure air into the airway as the patient sleeps, keeping it patent.

Question 23

what type of resp failure can alveolar hypoventilation cause

Answer 23

insufficient movement of air in and out of the alveoli means that carbon dioxide is not able to diffuse out of the bloodstream along its concentration gradient. It can therefore accumulate, causing type 2 respiratory failure (type 2 respiratory failure = problem with 2 gases).

Question 24

what type of respiratory failure does diffusion impairment cause.

Answer 24

type 1, because CO2 dissolves so much faster than oxygen, arterial CO2 is unlikely to be a problem in diffusion impairment.

Question 25

what is the most common sleep apnoea

Answer 25

obstructive apnoeas, where the negative pressure generated by the respiratory movements of the chest wall draws the upper airway tissues inwards and obstructs the airway.

Question 26

what are most cases of sarcoid treated with

Answer 26

many cases are mild and self-limiting and do not require any treatment. In many other instances, treatment with topical steroids or NSAIDs (eg ibuprofen) may be sufficient.

Question 27

is pulmonary fibrosis a risk factor for lung cancer

Answer 27

yes, the chronic inflammation of interstitial lung disease increases the risk of developing lung cancer.

Question 28

when is the pseudoglandular stage of lung development

Answer 28

between weeks 5-17, this stage involves rapid branching of the airways to form primitive segmental bronchi, and development of specialized cells such as ciliated cells and mucus-producing cells.

Question 29

what patienyts have longer peroids of anticoagulation

Answer 29

patients whom we do not know the cause of thei pulmonary embolism meaning it is more likely to occur again becuase we do not know what to treat it with

Question 30

how many people in northern europe are carriers of CF

Answer 30

about 1/25

Question 31

what do d dimer blood tests have

Answer 31

a high negative predictive value and a low positive predictive value for pulmonary embolism.

This means that if a d-dimer blood test is negative, you are very unlikely to have a PE. However, if the test is positive, there are lots of things that may explain this, so more tests are needed. Remember, a d-dimer blood test is an indication of intravascular blood clotting.

Question 32

what does farmers lung refer to

Answer 32

hypersensitivity pneumonitis caused by exposure to thermophilic actinomycetes.

Question 33

what will the chloride concentration in sweat be for someone with CF

Answer 33

highhhhhhhhhhhhhhhhh !!!

Question 34

when does the alveolar stage of lung development begin

Answer 34

36 weeks gestation

Question 35

what is haemoptysis in CF usually caused by

Answer 35

destruction of the bronchial walls through the CF disease process.

Question 36

what are most cases of pulmonary hypertension due to

Answer 36

underlying heart or lung disease

Question 37

what does raised PaCO2 cause in chronic ventilatory failure

Answer 37

chronic ventilatory failure is compensated by an elevated bicarbonate, so the pH is normal. Acute ventilatory failure will give a low pH due to acutely elevated PaCO2.

Question 38

where does hypersensitivity pneumonitis predominantly effect

Answer 38

most (but not all) lung diseases caused by inhaled antigens will predominantly affect the upper regions of the lungs.

Question 39

whta is normal paCO2

Answer 39

normal CO2 is 4.8-6.0 kPa

Question 40

where does alveolar hypoventilation effect

Answer 40

alveolar hypoventilation describes a global (or majority) lung problem, where insufficient air is moving in and out of the whole lung. Holding your breath induces alveolar hypoventilation! Most or all of the lungs need to be affected for CO2 to accumulate, because CO2 is so good at dissolving and diffusing that clearance is still sufficient with a small amount of functioning ventilated lung.

Question 41

what may a patient who becomes hypoxaemic on exertion have

Answer 41

diffusion impairment, diffusion impairments in lung disease (such as interstitial lung disease) mean it takes longer for the blood and air oxygen to equilibrate. If you give the blood less time in contact with the alveoli (e.g. by increasing the heart rate during exercise) then often the arterial oxygen levels will fall.

Question 42

when is surgery offered for pneumothorax

Answer 42

after the second one

recurrence rate of pneumothorax after a second pneumothorax is about 67%, therefore surgery is generally offered.

Question 43

when are gas exchanging units formed i the lung

Answer 43

canaliccular stage

Question 44

what is transient tachypnoea of a newborn due to

Answer 44

TTN is due to delayed reabsorption of pulmonary fluid at birth, and is a self-limiting condition. Infant Respiratory Distress Syndrome is caused by surfactant deficiency.