Respiratory Control Flashcards
In what area of the brain is the Pre-Botzinger Complex and what does it do?
- medulla
- generates “core” rhythm
In what area of the brain is the Pontine Respiratory Group and what does it do?
- pons
- modifies inspiratory timing (“turns off” inspiration)
- -when lesioned … “stuck in inspiration” (apneusis)
In what area of the brain is the Dorsal Respiratory Group?
- medulla, slightly off midline (near dorsal motor nucleus of vagus and hypoglossal nucleus)
- corresponds to the caudal end of the nucleus tractus solitarius
For what part of breathing is the Dorsal Respiratory Group responsible?
- depth of breathing
- tidal volume
-95 percent premotor to phrenic N.
Where is the Ventral Respiratory Group?
- medulla
- corresponds roughly to nucleus ambiguus
For what part of breathing is the Ventral Respiratory Group responsible?
-inspiration, exhalation, and depth
- premotor to phrenic N. and other inspiratory mm.
- premotor to upper airway and expiratory mm.
What is the visible appearance of apneusis versus the appearance of apnea?
apneusis: maintained inspiratory discharge
apnea: absence of respiratory effort
What area of the brain, if damaged, is responsible for apneusis versus the area responsible for apnea?
- apneusis: pontine damage
- apnea: medullary or spinal cord damage
What are the effects of apneusis versus the effects of apnea?
- increased carbon dioxide
- decreased oxygen
- death, if not supported
-in apneusis, this happens after a slight delay
What is chemosensitivity?
- the ability of certain chemicals to change the discharge rate of sensitive neurons
- in the respiratory system, the major chemicals are oxygen, carbon dioxide and hydrogen ion
What are characteristics of central chemoreceptors?
-directly sensitive to pH of CSF
(indirectly to carbon dioxide in plasma)
-influences the drive to breathe
-increases RR in response to hypercapnia
What are characteristics of peripheral chemoreceptors?
- directly sensitive to oxygen, carbon dioxide and H+
- influences acute change in blood gases
-increases RR in response to hypercapnia, hypoxia, or acidosis
Where are the central chemoreceptors located?
-on the ventral surface of the brainstem
Where are the peripheral chemoreceptors located?
- aortic arch
- carotid body
Which reactions are faster, those of the central chemoreceptors or those of the peripheral chemoreceptors?
peripheral
What are the characteristics of the Slowly Adapting Pulmonary Stretch Receptors?
- located in the airways
- stimulated by stretch of the lung
- inhibits inspiration and promotes exhalation
- in infants, it plays a role in every breath
- -in adults, only during increased tidal volume
What are the characteristics of Rapidly Adapting Pulmonary Stretch Receptors?
- located in the airways
- stimulated by irritants, stretch, foreign bodies
- causes a cough to clear airways
- protective role: not active every breath
What are the characteristics of Juxtacapillary (J) receptors?
- located near capillaries in the alveoli
- stimulated by pulmonary edema
- causes a cough and tachypnea
- protects gas exchange surfaces
- -not active every breath
What are the characteristics of cortical influences on breathing?
- controls breathing while talking, holding breath, etc.
- cortex appears to bypass the medullary ctrs completely and sends input directly to phrenic N. and muscles of respiration
