Exam III Flashcards
If the rib cage is totally immobile, how is inspiration possible?
By diapragmatic breathing
During expiration, what is the relationship between alveolar, atmospheric and pleural pressures?
Alveolar P > atmospheric P > pleural P
At which point is the only time that alveolar pressure is equal to pleural pressure?
End of inspiration and end of expiration
Which muscles are active during inspiration?
Diaphragm, external intercostalis, SCM, anterior serratus, scaleni, serratus posterior superior, levator costarum
Which muscles are active during expiration?
Rectus abdominus, int/ext obliques, transverse abdominus, internal intercostalis, serratus posterior inferior, transversus thoracis and pyramidal
Which muscle drops the floor of the thoracic cage on inspiration?
Diaphragm
Which muscle, in expiration, has a role in lower back pain?
Transverse abdominus
True/False: Under resting conditions, expiration is passive.
True
If the visceral pleura erodes and allows a region of the alveolar space to communicate with the pleural space, what would happen to the functional residual capacity?
It would be decreased
What describes hysteresis at the onset of inspiration?
The pleural pressure changes at a faster rate than lung volume
What is the function of a surfactant?
Reduce surface tension forces
Surfactants are produced by which cells?
Type II alveolar epithelial cells
What effect will histamine binding to H1 receptors have on the airway smooth muscle?
Constriction
What effect will histamine binding to H2 receptors have on airway smooth muscle?
Dilation
What effect will histamine binding to PG-E receptors have on airway smooth muscle?
Dilation
What effect will histamine binding to PG-F receptors have on airway smooth muscle?
Constriction
Most of the recoil tendency of the lung is due to:
Surface tension forces (2/3)
[1/3 comes from elastic CT]
What are the pathophysiologic consequences of hyperventilation?
SV and CO, coronary blood flow, cerebral blood flow and serum potassium all decreased, Repolarization of heart impaired, oxyhemoglobin affinity increased and skeletal muscle spasm/tetani
What is the common thread in most of the pathophysiologic consequences of hyperventilation?
Hypocapnic alkalosis
What is the major effect of sympathetic stimulation on airway smooth muscle?
Dilate, most of the effect is direct via blood borne (dilate B receptors)
Why is the left ventricular output slightly higher than the right ventricular output?
Some bronchial artery blood drains into the pulmonary veins
Which volumes or capacities can’t be determined with basic spirometry?
Residual volume, function residual capacity and total lung capacity
Function residual capacity is equal to:
The sum of residual volume + ERV
Total lung capacity is equal to:
Residual volume + ERV + IRV + TV