week 5 Flashcards
what does bronchial circulation supply
the lung parenchyma
where does bronchial circulation originate from 2
thoracic aorta
3rd ICS artery
drainage of bronchial circulation
1/3 will drain straight into pulmonary veins
2/3rds will drain into azygous and hemiazygous veins
when do the internal interocostals work
during expiration
when do the external intercostals contract
inspiration
what are the 2 key functions of lymph drainage in the lungs
allows removals of pathogens
allows removal of excess fluid
process of normal cough breathing (5 key steps)
- stimulation of sensory fibres
- AP transmission by vagal nerve fibres
- enters nucleus of solitary tract
- communicates with nucleus of the central pattern generator
- modulates ventral respiratory tract which controls the motor neurons responsible for inspiration and expiration
alveolar and pleural pressure during inspiration
both negative
alveolar and pleural pressure during expiration
alveolar = positive
pleural = less negative
what are the 2 key characteristics that control breathing
lung compliance
airway resistance
work of breathing
energy required to overcome the airway resistance and compliance
transmural pressure def and what it determines
pressure across the chest wall
controls collapse and distension
transpulmonary pressure def and what it determines
pressure difference between alveoli and the pleura
determines the level of lung expansion
what does greater compliance look like on a pressure volume loop
steeper slope and to left
what does lesscompliance look like on a pressure volume loop
flatter slope and to right
what are the three components which produce airflow resistance
airways = vessel diameter
chest wall
pulmonary = lung elasticity
what control 2 groups control bronchodilation/constriction
vagal = bronchoconstriction
sympathetic = bronchodilation
what area of the lung will always recieve blood
the base as arterial pressure is always greater than pulmonary pressure
how much blood will zone 2 of the lungs gain
will only gain blood during systole
how much blood will zone 1 of the lungs gain (apices)
lack of blood flow as alveolar pressure greater than arterial pressure
what substances cause increased pulmonary vascular resistance
endothelin - causes smooth muscle contraction
catecholamines - cause vasoconstriction
what substances cause a decrease in pulmonary vascular resistance
adenosine
nitric oxide
bohr effect
increased hydrogen and co2 will cause increased offloading of o2 in the tissues and increased o2 loading at the lungs
haldane effect
the greater the binding of oxygen to haemoglobin the greater the release of carbon dioxide
what will cause the HB oxygen dissociation curve to shift to the right
increased co2
increased hydrogen
decreased pH
increased temp
what affects diffusion capacity
surface area of diffusion surface
physical properties of diffusion surface
what does a v/q of 0 mean
there is perfusion but no ventilation
indicates an intrapulmonary shunt
what does a v/q of infinity look like
there is ventilation but no perfusion
indicates alveolar dead space
where is the respiratory centre located
medulla
what is the dorsal respiratory group important for
inspiration
what is the ventral respiratory group important for
inspiration and expiration
what is the apneustic pontine group important for
delays inspiratory off switch
what is the pneumotaxic pontine group important for
limiting depth of breathing
communication pathways of central and peripheral chemoreceptors
central = direct communication with respiratory centre
peripheral = communicate via the vagal and glossopharyngeal nerve
j receptors (location, what they detect, what they cause)
near pulmonary capillaries, detect changes in pressure, cause tachypnoea
what are the 3 forms of pulmonary function testing
spirometry
single breath diffusing capacity of carbon monixide
subdivisions of lung volume
what does spirometry test for
obstructive and restrictive lung disease patterns
what is an obstructive spirometry
FEV1/FVC ratio is reduced
what is a restrictive spirometry
FEV1/FVC ratio is reduced or the samee
FVC is reduced
what does subdivisions of lung volume test for
used as an indicator of static lung compliance
what is static lung compliance
the change in lung volume per unit of pressure
what does single breathing diffusing capacity of carbon monoxide test
diffusion capacity according to fick’s law
what does high diffusion capacity mean 3
high haemoglobin
polycthaemia, erythrocytosis
what does low diffusion capacity mean 4
reduced haemoglobin
anaemia, PE, emphysema
what would be investigations for dyspnoea presentation 7
History
Resp exam
ECG
Troponin
CXR
PFT - Spirometry
CTPA
function of concha
increase surface area for humidification, filtration and air warming
negligence
failure to take resonable care resulting in injury
battery
physical contact, medical examinations, treatments and interventions without consent
medical tort
when a law suit is taken against a medical professional. It is filed under the grounds of negligence or battery
anterior descending features of the larynx cartilage 5
hyoid bone
thyrohyoid membrane
thyroid cartilage
criothyroid membrane
cricoid cartulage
posterior descending features of the larynx cartilage 4 (CCCA)
cunieform cartilage
corniculate cartilage
cricoid cartilage
arytenoid cartilage
