EOM: RESP Flashcards
What do all chemoreceptors detect?
PaCO2
In the control of human breathing:
Centres in both the pons and medullar oblongata are important
What stimulates the main motor function of the larynx?
Recurrent laryngeal nerve
What should be considered for the emergency chest drain position?
Angle of Louis/second intercostal space position - marks the site of bifurcation of the trachea into the right and left main bronchi (as well as corresponding with the upper border of the atria).
Describe the two main differences between the right and left main bronchi.
Right is more vertically disposed and left is closely related to aortic arch
Gas exchange depends on:
Supplying bulk gas to the alveoli and the movement of blood - occurs through a membrane around 1 micrometre thick.
Describe what happens to the diaphragm during inspiration.
Contracts and flattens
Define physiological dead space.
The volume of air in the conducting airways which does not contribute to gas exchange, plus the volume of air in the alveoli which does not contribute to gas exchange.
What is the effect of hypoxia on blood vessels?
Vasoconstriction
Arterial PaCO2 depends on:
Production of CO2 and alveolar ventilation
What happens in respiratory acidosis?
PaCO2 initially rises - overtime the kidneys will reabsorb more bicarbonate to buffer.
Define FEV1.
Volume of air expelled after 1 second of forced expiration
A patient has the following function:
- FEV1 = 1.6 L (normal = 3.2 L)
- FVC = 4.8 L (normal = 4.7 L)
Diagnose the patient.
Airways obstruction (reduced FEV1)
- Typical physiology for COPD and chronic asthma (to diagnose, observe response to salbutamol inhaler)
- For airways restriction, FVC has to be less than 80% predicted
Carbon monoxide single breath transfer factor (TLCO) is a good estimate of:
Gas exchange into alveolar capillary
What happens to the physiology of a climber when they ascend a mountain?
CO2 drops due to hypoventilation, causing pH to rise and pressure of inspired oxygen to fall.
