Term
| Where do neuronal innervations for breathing originate? |
|
Definition
| cervical and thoracic spinal cord segments |
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Term
| Where are the respiratory "pacemakers"? |
|
Definition
| medullary and pontine complex |
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Term
| How does the rostral pons pace respiratory rhythms? |
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Definition
| it increases resp rate by cutting shot inspiration |
|
|
Term
| How does the caudal pons pace respiratory rhythms? |
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Definition
| it decreases resp rate by prolonging inspiration |
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|
Term
| Where is the pneumotaxic center? |
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Definition
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Term
| What is the best clinical indicator of ventilation? |
|
Definition
PaCO2
PaCO2 > 45 mmHg = hypoventilation/respiratory acidosis
PaCO2 < 35 mmHg = hyperventilation/respiratory alkalosis |
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Term
| where are the central chemoreceptors located? |
|
Definition
|
|
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
|
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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 |
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|
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
|
|
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
|
|
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 |
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|
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
|
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
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|
|
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
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Term
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Definition
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