WEEK 3 - chronic breathlessness Flashcards
(115 cards)
sympathetic innervation of bronchiolar smooth muscle is mediated by ______ acting on ________ to cause ________.
parasympathetic innervation of bronchiolar smooth muscle is mediated by _______ acting on ______ to cause ________.
- noradrenaline
- beta receptors
- bronchodilation
- acetylcholine
- muscarinic receptors
- bronchoconstriction
type I vs type II alveolar cells
type I
- gas exchange between the alveoli and capillaries
- larger squamous (flattened) cells
- no secretory organelles present
- less numerous than type II
type II
- secrete surfactant to lower surface tension
- smaller cuboid-shaped cells
- secretory organelles present
- more numerous than type I
the lungs have dual arterial supply and venous drainage, comprised of the ________ arteries and veins, and the __________ arteries and veins.
the pulmonary arteries supply _________ from the ______ to the _____ capillary network. the pulmonary veins drain _______ blood to the _________.
the bronchial artiereis supply ________ blood from the ________ to the lung tissues. the bronchial veins drain ________ blood to the pulmonary and systemic venom systems
- pulmonary
- bronchial
- deoxygenated
- right ventricle
- alveolar
- oxygenated
- left atrium
- oxygenated
- thoracic aorta
- deoxygenated
what is the MRC (medical research council) dyspnoea scale?
a scale to make an objective assessment of the symptom of breathlessness when taking a history
breathlessness when lying flat is a key symptom of what?
congestive cardiac failure (CCF) (orthopnoea)
bilateral vs unilateral ankle swelling
bilateral — sign of cardiac pathology, esp CCF
unilateral — may indicate DVT/PE
what classically can cause breathlessness with lightheaded mess?
aortic stenosis
why ask about exposure to birds?
hypersensitivity pneumonitis
a type of hypersensitivity pneumpnitis due secondary to repeated inhalation of avian antigens is seen in bird keeps
sometimes known as ‘Pigeon Fancier’s Lung’
what are the hallmark symptoms of COPD?
- SOB
- chronic cough
- sputum production
other features:
- winter exacerbations
- wheeze
what are the physical signs of COPD?
- accessory muscle use
- auscultation
- chest hyperexpansion
- chest wall movement
- tar-staining
- peripheral oedema
- palpable liver
- pursed lip breathing
explain pursed lip breathing
this enables a patient to reduce their resp rate by increasing their period of expiration; it creates resistance to expiratory airflow and development of a positive expiratory pressure in the airways, reducing airway collapse and aiding ventilation
in COPD, what impede the effective chest expansion by the diaphragm and intercostal muscles? what does the patient do instead?
air trapping and hyperinflation
instead the patient used accessory muscles (inc SCM, scalene, trapezius and abdominal muscles) to aid ventilation
what does peripheral oedema in COPD indicate?
right-sided heart failure due to cor pulmonale
what is cor pulmonale?
abnormal enlargement of the right side of the heart as a result of disease of the lungs or the pulmonary blood vessels
why might you get a palpable liver in COPD?
may be due to hyperinflation of the lungs or congestive heart failure
what would you hear in auscultation of COPD?
- reduced breath sounds
- reduced heart sounds
- tachypnoea
- wheeze
during an exacerbation there may also be crepitations
describe chest wall movement in COPD
- reduced lateral (bucket handle) chest expansion
- increased vertical (pump handle) chest expansion
what rare genetic condition can cause COPD at a young age, esp in smokers?
alpha-1 anti trypsin deficiency
what is the gold standard investigation for diagnosing COPD and grading COPD severity?
spirometry
what are 3 histological features of COPD? what symptoms do they cause?
- goblet cell hyperplasia — cough and sputum
- airway narrowing — breathlessness and wheeze
- alveolar destruction — breathlessness
inflammation mediated by the toxic substances of tobacco smoke cause these things
how does NICE define airflow obstruction?
post-bronchodilator FEV1/FVC ratio such that FEV1/FVC is less than 0.7
(above 70% is normal)
FEV1/FVC obstructive vs restrictive disease
O = <75%
R = > 75% (FEV1 and FVX are reduced in roughly the same proportion so the ratio remains within the normal range)