Unit 2: Pulmonary Physiology Flashcards
Anatomical dead space is a reflection of the size of the conducting airways. What are some things that could affect the size of the airwyas?
- Radius: emphazema, smoking, mucus
- Length: height of person
- Minute-to-minute ventilaiton: tube on ventilator
What does a Ventilation/Perfusion scan assess?
- Ventilation
- Perfusion
- Possible diagnoses
- Ventilated (V) but not perfused (Q): pulmonary emboli *picture*
- Q but not V: airway blocking or narrowing
- Neither V nor Q: COPD or pneumonia

What are the two types of sleep apnea?
- Central Sleep Apnea
- Obstructive Sleep Apnea
In pulmonary perfusion, what is zone 2?
- Intermediate zone
- received intermittent blood flow - based on difference between arterial and alveolar pressures
What 3 factors can affect normal airway distribution?
- Airway obstruction
- Abnormal lung or chest wall compliance
- Respiratory muscle weakness
How would an increase in right ventricular stroke volume affect pulmonary artery pressure?
Results in greater pulmonary artery pressure and will cause zone 3 to extend farther up each lung (more gravity dependent = needs more blood)
What is Central Sleep Apnea?
- Failure of respiratory centers
- Can be result of:
- Encephalitis
- Brainstem infarction
- Bulbar poliomyelitis
What are the respiratory control mechanisms during disease like diabetes?
ketoacidosis leads to dec pH → fires off peripheral chemoreceptors → inc ventilation and blowing off excess acid
What is elastic recoil in the lungs?
The ability of the lungs to return to their original shape after stretch.
What breaks up surface tension in the lungs?
Surfactant
What does the Apneustic Center do?
<em>Ex Phys Notes</em>
- Works opposite the pneumotaxic center - prevents inspiratory neurons from switching off.
- Normally inhibited by pneumotaxic center
- NO role in normal respiration
**Absence of inhibition, apneustic center produced prolonged inspirations followed by short expiratory gasping (head injuries)**
What is Flow of Air dependent on?
Flow of air is related to pressure gradient and to the resistance of the airways.
Q (flow of air) = _/_ P/R (change in pressure over resistance)
Obstructive Sleep Apnea is sometimes referred to as __________ Syndrome.
Pickwickian
What is Kussmal’s breathing seen as an attempt to compensate for?
Metabolic acidosis (ex: diabetic ketoacidosis)
How would an increase in pulmonary vascular resistance affect perfusion?
Increase in resistance would decrease perfusion
Does anatomical dead space participate in gas exchange?
No
What are the two distinct respiratory groups (cluster of cells) located in the respiratory center?
<em>Ex Phys Notes</em>
- Dorsal Respiratory Group (DRG) or Nucleus Tractus Solitarius (NTS)
- Ventral Respiratory Group (VRG) or Nucleus Ambiguous
What is Hypoventilation?
What does its breathing pattern look like?
Shallow respirations (often irregular)

What is respiratory distress syndrome (RDS)?
- Occurs in premies before 26-28 weeks
- Born before surfactant is produced and breathing is difficult
What patient populations experience Cheyne-Stokes breathing?
Severe cardiac failure
Head injuy
What is the concern with descreasing tidal volume while increasing respiratory rate?
work of breathing (WOB) decreases tidal volume (TV) - patient cannot get good air down to alveolie because it is all in dead space
What produces surfactant in the lungs?
Type II alveolar cells
What is Eupnea?
How many breaths/min?
What does its breathing pattern look like?
Normal breathing rate and rhythm
12-20 breaths/min

Where is the Apneustic Center located?
<em>Ex Phys Notes</em>
Lower part of the pons








