Respiratory Flashcards
What is FIV and how does it relate to airway constriction?
Forced Inhalation Volume - a constricted airway will take longer to reach FIV.
Allergies relate to which white blood cell?
Mast cell sensitisation by IgE.
Which 3 anatomical features mark asthmatic airways?
- Smooth muscle hypertrophy
- Fibrosis
- Goblet cell hyperplasia
What does 100% FVC indicate?
100% Forced Vital Capacity indicates that the patient could get all the air out of their lungs, so any issue must be obstructive not restrictive.
What features are unique to cervical vertebrae?
Butterly spinous processes and extra holes in transverse process for vertebral arteries.
What is the most common neural tube defect?
Spina Bifida
Name an intrinsic muscle of back
Erector Spinae
Which thoracic muscle can move anterior to posterior and posterior to anterior?
Transverse abdominis
How would you define asthma?
Reversible airway obstruction
Which 3 physiological features are present in asthma?
- bronchoconstriction
- mucus increase
- inflammation leading to cough
What is emphysema?
Loss of alveolar membrane - they start to join - decrease surface area
How does smoking impact the lungs? x5
- kills cilia
- mucus hypersecretion
- kills macrophages, chronic inflam
- neutrophils make proteases and break down bronchiole elastin –> gas trapping
- fibrosis
If you have chronic raised CO2, which reflex will kick in to control breathing?
- O2 detection (carotids)
- Stretch receptors in lungs
THIS IS HYPOXIC BREATHING
How to tell if someone’s respiratory rate is running of hypoxia?
- RR will be chronically low
Hypoxia sends what message to the kidneys?
To release EPO - to make more red blood cells.
Which people are most at risk of sleep apnea?
Obese or super skinny - both due to floppy soft palate.
A wheeze suggests what type of issue?
obstructive
Barrel chest gives what finding on CXR?
Retrosternal shadow
What is FEV1/FVC?
Amount of air that can be forcibly pushed out in 1 second / amount of air that can be pushed out total. COPD is less than 70.
What oxygen % will cause sleep apnea to wake someone up?
60%
Describe a pneumothorax and the examination findings of a pneumothorax
Air leaking into the pleural space, pushes on lungs.
Trachea will be pushed away from site of injury.
Expansion will be less on affected side.
Percussion of area will be hyper resonant due to being air.
Auscultation will show reduced/absent breathing sounds as it’s not liquid or solid.
Vocal resonance will be muffled.
Describe pneumonia and the examination findings
Infection of the lung, typically lobar.
Trachea will be midline.
Expansion will typically be unaffected.
Percussion will be more dull at site.
Auscultation will show crackles and louder breath sounds maybe.
Vocal resonance will be hyper resonant - clearer.
Describe a collapsed lung and the examination findings
Internal collapse of lung structures due to things like cancer.
Trachea will move towards collapse as it is being pulled in.
Expansion reduced on affected side.
Percussion will be dull.
Auscultation will be absent cos no air getting in.
Vocal resonance will be really clear.
Describe a pleural effusion and the examination findings
Liquid build up at bottoms of pleural space.
Trachea normal in midline.
Expansion normal.
Percussion will be duller. STONEY Dullness.
Auscultation will be absent due to weird physics mechanism.
Vocal resonance will be absent due to weird physics.
Stoney Dullness is a giveaway for what condition?
Pleural effusion
What factors prevent damage/irritant of the trachea?
IgA, cilia, irritant receptors, mucus, antimicrobials, alveolar macrophages riding the wave.
Rust coloured sputum is a giveaway for what organism and disease? How would you treat it?
Strep pneumoniae caused pneumonia.
Amoxicillin.
What is the most common ECG finding for a PE?
Sinus tachycardia
What are Type 1 and Type 2 Hypoxia and what typically causes type 2?
Type 1 - just oxygen hypoxia
Type 2 - oxygen and CO2 issues.
Type 2 tends to be due to hypoventilation.
Which WBC are most important in asthma vs COPD
Asthma is eosinophilic, COPD is neutrophilic.
What is atypical pneumonia and how does it look on CXR?
‘walking pneumonia’, less intense symptoms, tend to be hospital acquired, diffuse grey on CXR.
Mnemonic for all the important squamous cell carcinoma stuff:
Having a milkshake on Sydney Harbour Bridge, its a pearler of a day.
Calcium up due to paraneoplasia, keratin pearls on histo, people are squashed together (squamous).
Describe the lobes of the lungs.
The right lung has 3 lobes, the left has 2.
In right lung - middle love is smallest, all of the lobes touch each other.
describe the fissures of the lungs.
Right Lung - horizontal fissure between middle and superior lobes, oblique fissure between middle and inferior lobes.
Left Lung - just oblique fissure
What is the Lingula?
Tongue like projection of left lung over heart bulge.
Which lung is shorter.
The right lung is shorter due to the liver pushing up the diaphragm.
Describe the left and right hilum
Left - pulmonary artery is superior, bronchus is most posterior, pulmonary veins are most inferior and anterior. Pulmonary ligament below.
Right - Bronchus is superior and posterior - usually in 2, artery is anterior and veins inferior.
Do the pulmonary arteries and veins supply the lungs?
No they are for gas exchange only.
The bronchial arteries supply the lungs. The left has 2, the right has 1.
Where does the trachea start and end?
Starts at the cricoid cartilage, C6.
Ends at the carina - transverse thoracic plane, T4/5.
The left bronchus passes under what?
Aortic arch
Which lung are inhaled objects more likely to go to?
the right lung, because the main bronchus is more vertical.
Which muscles are used for uncomplicated inspiration?
Diaphragm and external intercostals are enough.
What are the 4 nerves of breathing?
Hypoglossal nerve - depresses tongue to allow air in - goes first
Superior laryngeal - abducts airway muscles to open airway - goes first with above
Phrenic - diaphragm descends - second
Pharyngeal branch of the vagus - adducts throat muscles to slow expiration
How does the adult body reduce alveolar pressure? Do kids have less or more pressure?
Via surfactants made by type 2 alveolar cells.
Kids have smaller alveoli, so the pressure is greater.
What is a rightward shift of Hb binding and what causes this?
Easier for Hb to bump off oxygen.
- high temp
- high pH
- high CO2
- raised BPG (altitude)
Why is Hb binding described as sigmoidal/cooperative?
Binding of 1 O2 to Hb encourages binding of O2 to the 3 other sites on the Hb.
Which cells decrease in the bronchioles and which increase?
Goblet cells tend to be replaced by Clara cells.
What epithelial types makeup the respiratory system?
Most of it is pseudostratified columnar epithelium with cilliated cells but the alveoli are squamous.
Describe the histology layers of the trachea?
Starts with epithelium, then basal lamina, then lamina propria. Those 3 form the mucosa. Then have the submucosa, then the adventitia (connective tissue).
Explain central detection of hypoxia.
Central chemoreceptors are in the medulla. They detect H+ and will activate signals to fix the issue (breath more etc). - SNS activation etc.
What is the diagnostic test for asthma and other respiratory conditions?
Spirometry
Why do asthmatics wheeze?
Wheeze is due to an obstructive issue. The narrowed bronchioles will shut on expiration - cause wheeze.
What is bronchiectasis?
Permanent pathological dilation of bronchus.
How do adrenergic drugs work for asthma?
SABAs and LABAs are agonists of B2 adrenergic receptors in the lung tissue, stops calcium building up to prevent contraction of muscle in bronchioles - same mechanism as heart drugs mate just opposite.
Anti-muscarinic drugs typically end in what suffix?
-bromide.
Which drugs are useful and not so useful for COPD?
useful - LAMAs
shit - steroids
What is the main viral cause of pneumonia?
Influenza
What are the macro stages of pneumonia?
- Congestion
- Red hepatisation
- Grey Hepatisation
- Resolution - normal or scar
What is the classic atypical pneumonia pathogen?
Mycoplasma pneumonia
What is the most common consequence of aspiration pneumonia and how would you know if you had it?
Abscess pneumonia - sputum would fucking stink.
What are the key findings for TB on CXR?
Gohn foci - typically upper lungs.
Gohn complex - if at hilum.
How do central vs peripheral tumours tend to show up on presentation?
Central - obstruct airways leading to wheeze
Peripheral - tend to cause pleural effusion
Which lung cancers are typically central and which are peripheral.
Adenocarcinoma usually peripheral.
Small cell and squamous cell usually central.
Key squamous cell carcinoma histo feature?
Keratin pearls
Name 3 causes each of hepatic, pre, and post.
Pre - haemolysis (infection, drugs), albumin competition, low albumin
Hepatic - cirrhosis, hepatitis, cancer
Post-hepatic - stones, cancers, parasites.
Will pneumonia cause haemoptysis?
Not usually
Classic triad of pulmonary embolism?
- haemoptysis
- Chest pain (pleuritic)
- Cough
What is a key virulence factor of the organism that typically causes an infected throat?
Strep pyogenes - M protein.
Which virus famously causes bronchiolitis in kids?
RSV
Which two bacteria love to cause abscesses in the lungs?
Klebsiella and Staph
What histo colours are Squamous and small cell carcinomas?
Squamous - very pink
small cell - very purple
Which lung cancer can’t be resected?
Small cell, needs chemo
If the lung is full of tumours, what does this mean? If those lesions are black?
Likely a metastatic cancer. If they’re black = metastatic melanoma
Why should asthmatics be watched carefully for 24 hrs after an attack?
Late phase reaction by T helper cells
What does a cavitation in the lung indicate?
An old abscess
What are two possible side effects of salbutomol aside from tachycardia?
Hyperglyceamia and hypokalemia
What is the body’s main breathing rate mechanism?
H+ detection in the brainstem
Name two key histological features of squamous cell carcinoma
Intercellular bridges and keratin pearls
Which organism causes ‘red jelly’ sputum?
Klebsiella
Which ligament protects the spine from disc herniation?
Posterior longitudinal ligament
Describe the expansion and FEV1/FVC of interstitial lung diseases.
Reduced expansion, normal FEV1/FVC
Keratosis is a precursor to which skin cancer?
Typically squamous cell carcinoma
Which T helper type controls allergies and asthma?
Th2
What type of respiratory failure could pneumonia cause?
Type 1 - O2 only, not CO2
