Respiratory Formative Assessment Flashcards
What is true about all chemoreceptors
They all sense PaCO2 levels
How many nasal turbinates are there on each side
3
In control of human breathing
Centres in both the pons and medulla oblongata are important
Main motor function of the larynx is supplied by which nerve
Recurrent laryngeal nerve
Which rib is lateral to the sternal angle
2nd rib
The right main bronchus is …… than the left main bronchus
More vertically disposed
Where to place an emergency chest tube
between the mid to anterior axillary line in the fourth or fifth intercostal space tracking above the rib so as not to injure the intercostal bundle (artery, vein, nerve).
Gas exchange between alveolus and haemoglobin
Occurs through a membrane approximately 1 micron thick
During inspiration the diaphragm
Contracts and descends
The physiological dead space is defined as
The volume of air in the trachea and main bronchi that doesn’t contribute to gas exchange plus the volume of air in the alveoli that doesn’t contribute to gas exchange
Alveolar dead space + anatomic dead space
Approximate physiological dead space
175 mls
Hypoxia (low oxygen levels) causes…. In the lungs
Vasoconstriction
Arterial PaCO2 depends on
A constant, the production of CO2 and alveolar ventilation
PaCO2=
k VCO2 / V’A
The oxygen/haemoglobin dissociation curve is influenced by
Changing affinity for sequential oxygen molecule binding
In respiratory acidosis
The PaCO2 initially rises
The FEV1
The volume of air expelled after one second of forced expiration
A patient with breathing problems has the following lung function: FEV1 1.6 litres (predicted value 3.2 litres) and FVC 4.8 litres (predicted value 4.7 litres).
The patient has airways obstruction and a reduced FEV1
The carbon monoxide single breath transfer factor:
Is a good measure of gas exchange into the alveolar capillary
When a climber ascends a mountain, which statement best describes the physiology?
The pressure of inspired oxygen falls
Which of the following is NOT a feature of pulmonary oxygen toxicity (Lorraine Smith effect)?
Convulsions (CNS oxygen toxicity)
Which statement best describes the genetics of asthma
Is not caused by a single mutation (at least chromosome 2,6,9,15,17 and 22 are involved)
What does not cause occupational asthma
Mild steel welding
Arterial gas embolism
Gas enters circulation via torn pulmonary veins
Small transpulmonary pressures can lead to arterial gas embolism
Normally occurs within 15mins of surfacing
Urgent decompression required
Can occur in a swimming pool and shallow dives
the gene defect in cystic fibrosis is the CFTR found on;
Long arm of chromosome 7
which is the most clinical significant form of alpha 1 anti trypsin deficiency
PiZZ
The ductus arteriosus in the foetus joins the;
Pulmonary trunk to aorta
