Random Ass Facts For Resp Flashcards
When does surfactant production begin in foetal development?
Around week 22
What is the most common gene causing cystic fibrosis and how does it lead to mucus accumulation?
DeltaF508 (Phe508del) - the gene encoding the cystic fibrosis transmembrane conductance regulator, an ion channel involved in the transport of chloride ions in the respiratory and pancreatic epithelium, leading to mucus accumulation
This gene is on chromosome 7 at CFTR gene
What are sign to look out for in a baby’s and young children for undiagnosed cystic fibrosis?
wheeze, poor feeding and failure to gain weight, frequent chest infections
Failure to pass meconium (stool) - new borns
Failure to thrive, pancreatic insufficient (loose greasy stool due to lack of lipases)
What does a heel prick test confirm?
Cystic fibrosis
Lung cancer can present with ipsilateral elevation of the hemidiaphragm due to compression of what nerve?
Phrenic nerve
What does methaemoglobin do to the oxygen dissociation curve?
Shifts it to the left
What is methaemoglobinaemia?
- Where is iron molecule is F3+ and not F2+ so can not bind to oxygen
- occurs due to environmental agents or medications (e.g. lidocaine and trimethoprim) or genetic conditions such as G6PD deficiency and pyruvate kinase deficiency
What causes Bird fanciers lung?
Avian proteins from bird droppings
What causes tobacco workers lung?
Aspergillus spp.
What causes farmers lung?
Thermophilic actinomycetes
What is responsible for hot tub lung?
Mycobacterium avium
How can cystic fibrosis lead to infertility in men?
Cystic fibrosis is associated with absent vas deferens
What is the investigation of chronic to confirm the diagnosis of bronchiectasis?
High resolution computed tomograpahy (although a chest x-ray is normally carried out first)
Characteristic feature include:
- Bronchial wall dilation
- Lack of bronchial tapering
What are the characteristic features of bronchiectasis on chest x-ray?
- Thickened bronchial walls (tramlines)
- Cystic lesions with fluid levels
- Collapsed areas with crowded pulmonary vasculature
- Scarring
What is Kartageners syndrome?
Defect in the cilia which reduces the ability of the lungs to clear mucus - this progresses to bronchiectasis as repeated infections and inflammation cause the airways to become widened and oedematous
Which physiological changes do occur following a tracheostomy?
- alveolar ventilation increased
- anatomical dead-space is reduced by 50%
- proportion of ciliates epithelial cells in the trachea may decrease
- splinting of the larynx may lead to swallowing difficulties
What is the pathogen in the majority of cases of Bronchiolitis?
Respiratory syncytial virus (75-80% of cases)
Other causes: adenoviruses, mycoplasma or secondary to a bacterial infection
What is bronchiolitis?
Condition characterised by acute bronchiolar inflammation
Features:
- common cold symptoms (including mild fever)
- dry cough
- increasing breathlessness
- wheezing, fine inspirations crackles (not always present)
- feeding difficulties associated with increasing dyspnoea are often the reason for hospital admission
What is Ménière’s disease>
Disorder of the inner ear of unknown cause. It is characterised by excessive pressure and progressive dilation of the endolymphatic system
Features:
- recurrent episodes of vertigo, tinnitus and hearing loss (sensorineural). Vertigo is usually the prominent symptom
- a sensation of aural fullness or pressure is now recognised as being common
- other features include nystagmus and a positive Romberg test
- episodes last minutes to hours
- typically symptoms are unilateral but bilateral symptoms may develop after a number of years
What are the 3 bones in the ear?
- malleus
- incus
- stapes
Foreign bodies lodges in the piriform recess ma damage what nerve?
The internal laryngeal nerve
What is the mechanism of action of aminophylline?
Binds to adenosine receptors and blocks adenosine-mediated bronchoconstriction
What is Cholesteatoma?
A non-cancerous growth of squamous epithelium that is ‘trapped’ within the skull base causing local destruction. It is most common in patients aged 10-20 years. Being born with a cleft palate increases the risk of cholesteatoma around 100 fold.
Main features
- foul-smelling, non-resolving discharge
hearing loss
Other features are determined by local invasion:
- vertigo
- facial nerve palsy
- cerebellopontine angle syndrome
Otoscopy
- ‘attic crust’ - seen in the uppermost part of the ear drum
What to chemoreceptors respond to to increase ventilation?
Respond to increased H+ in BRAIN INTERSTITIAL FLUID
How does the body control ventilation?
- Control of ventilation is coordinated by the respiratory centres, chemoreceptors, lung receptors and muscles.
- Automatic, involuntary control of respiration occurs from the medulla.
- The respiratory centres control the respiratory rate and the depth of respiration.
What would normal rebuts be when the Rinne and Weber tests are carried out?
- Rinne result: Air conduction > bone conduction bilaterally
- Weber result: same in both ears