Shared Flashcard Set

Details

L8
Control of Ventilation
31
Physiology
Professional
02/27/2013

Additional Physiology Flashcards

 


 

Cards

Term
Where do neuronal innervations for breathing originate?
Definition
cervical and thoracic spinal cord segments
Term
Where are the respiratory "pacemakers"?
Definition
medullary and pontine complex
Term
How does the rostral pons pace respiratory rhythms?
Definition
it increases resp rate by cutting shot inspiration
Term
How does the caudal pons pace respiratory rhythms?
Definition
it decreases resp rate by prolonging inspiration
Term
Where is the pneumotaxic center?
Definition
rostral pons
Term
What is the best clinical indicator of ventilation?
Definition

PaCO2

 

PaCO2 > 45 mmHg = hypoventilation/respiratory acidosis

PaCO2 < 35 mmHg = hyperventilation/respiratory alkalosis

Term
where are the central chemoreceptors located?
Definition
ventro-lateral medulla
Term
where are the peripheral chemoreceptors located?
Definition
carotid bodies and aortic bodies
Term
What do the central chemoreceptors sense?
Definition
PaCO2 levels in arterial blood
Term
What surrounds central chemoreceptors?
Definition
CSF
Term
What is the primary response of central chemoreceptors to high PaCO2 levels?
Definition
control CO2 levels by making H+ ions and bicarbonate which cannot easily cross the blood-brain barrier
Term
What do peripheral chemoreceptors sense?
Definition
PaO2 levels primarily but also high PaCO2 levels or high H+ levels
Term
What PaO2 would the blood have to have before the peripheral chemoreceptors induced a response?
Definition
50-70 mmHg
Term
Where are pulmonary mechanical receptors located?
Definition
within the airway smooth muscle, alveolar walls and walls of the bronchial vasculature supplying the lung with systemic arterial blood
Term
Where are pulmonary stretch receptors located?
Definition
within smooth muscle of the airways
Term
How do pulmonary stretch receptors respond to activation?
Definition
They send vagal afferent signals to the central respiratory controller, terminating that breath (limited VT)
Term
Where are irritant receptors found?
Definition
in the alveolar septa
Term
What do irritant receptors respond to?
Definition
noxious gases and airborne irritants
Term
Where are juxtapulmonary receptors found?
Definition
within the alveolar walls close to pulmonary capillaries
Term
What do juxtapulmonary receptors respond to?
Definition
distortion of airways or blood passages (ie. alveolar edema, pulmonary emboli)
Term
What are Bronchial C fibers?
Definition
sensors located in the wall of the bronchial vessels that upon activation result in rapid, shallow breathing, mucous secretion and bronchoconstriction
Term
what happens when a person gets "the air knocked out of them"?
Definition
they reside at FRC with massive inhibition of inspiratory neurons. When the inhibitory NTs are washed away by the brainstem blood flow (~30 seconds), the person can breath again
Term
What happens to breathing when PaO2 values are normal (>70 mmHg) but PaCO2 levels are low (<32 mmHg)?
Definition
automatic breathing ceases as the body tries to increase PaCO2 levels
Term
What happens to breathing when PaO2 levels are low (<70 mmHg) and PaCO2 levels are also low (<32 mmHg)?
Definition
automatic breathing will continue due to hypoxic drive
Term
What happens if peripheral chemoreceptors are denervated and the pt has a PaO2 <70 mmHg but PaCO2 is normal/low?
Definition
Breathing will cease because there are no central receptors for low O2 in the blood
Term
What is eupnea?
Definition
normal breathing pattern at rest (active inspiration to Vt, passive expiration to FRC, and apneic pause)
Term
What are the two most common causes of abnormal breathing patterns?
Definition
  • CNS damage to brainstem or spinal cord
  • cardiovascular problems such as CHF
Term
What is Cheyne-Stokes breathing?
Definition
Cheyne-Stokes is characterized by spindle breathing, wide swings in tidal volume causing alternating periods of hyperventilation and hypoventilation
Term
What is apneustic breathing?
Definition
holding breath in the inspiratory position with only short expiratory reprieves
Term
What are characteristics of gasping?
Definition
  • arrhythmic breathing
  • uneven, quick tidal volumes at different intervals
Term
what is apnea?
Definition
cessation of breathing
Supporting users have an ad free experience!