control of breathing Flashcards
(31 cards)
what makes breathing a unique behaviour?
it is continuous from birth to death & occurs spontaneously
what is eupnea?
normal rhythmic breathing
what is dyspnea?
being short of breath, aware of difficult breathing
what must neuronal control of breathing do?
establish automatic rhythm
respond to metabolic demands
respond to mechanical changes
range of episodic nonventilatory behaviours
what are respiratory related neurons?
array of interconnected neurons, fire more APs during resp cycle
what are central pattern generators?
in brainstem/medulla, independently generate respiratory rhythm
what are respiratory motor neurons?
innervate resp muscles, axons via phrenic nerve innervate diaphragm
how can frequency of resp CPG change?
strength from central and peripheral receptors, change both depth and frequency of ventilation
where does the brain receive neural signals from?
chemoreceptors- blood PO3,PCO2 and pH
mechanoreceptors-mechanical status
where are neural signals sent to?
resp muscles- produce rhythmic breathing movements, upper airway muscles, produce reflexes
what are chemoreceptors?
sensory receptors that detect chemical changes in the surrounding environment
what do chemoreceptors detect in the resp system?
changes in PO2, PCO2 and pH
what responds to decreases in PO2 - hypoxia?
peripheral chemoreceptors
how are normal PO2 levels restored?
peripheral chemoreceptors stimulated, neural signals sent from carotid and aortic bodies to NTS in brainstem, ventilation increases
what are central chemoreceptors?
clusters of neurones in the brainstem that are activated when PCO2 is increased-hypercapnia, or pH decreased
how are normal PCO2 levels restored?
central receptors stimulated, info passed on to neuronal clusters in brainstem involved in generating breathing, ventilation increase
what is the effect of very small changes in PCO2 on ventilation?
large effects
what are mechanoreceptors?
sensory receptors that detect changes in pressure, movement and touch
what do mechanoreceptors detect in the resp system?
movement of lung and chest wall
what are 3 functions of mechanoreceptors?
pulmonary stretch receptors detect lung vol/muscle length, can terminate inspiratory effort, can adjust ventilation for changes in posture
how do mechanoreceptors adjust ventilation?
inflation activates them, neural signals sent via vagus nerve to NTS in brainstem, ventilation adjusted
what is NTS?
nucleus tractus solitaries- receives info from mechanoreceptors and peripheral chemoreceptors, processed in brainstem by resp neurons
what neurones are active during inspiration?
inspiratory neurones
describe resp rhythm generating neurones in brainstem
bilateral cluster of neurons with rhythm generating properties
