Central control of breathing Flashcards
What 3 vague afferent reflexes are present from mechanoreceptors?
Slowly adapting pulmonary stretch receptors
Rapidly adapting pulmonary irritant receptors
Pulmonary C fibres receptors (J receptors)
Where are slow adapting pulmonary stretch receptors located?
Large airways and visceral pleura
What is the function of slow adapting pulmonary strict receptors?
Terminate inspiration, limit tidal volume and extend expiration
Where are rapidly adapting pulmonary irritant receptors located?
Underneath airway epithelium at bifurcations
What is the stimulus of rapidly adapting pulmonary irritant receptors?
Rate of change
What is the function fo rapidly adapting pulmonary irritant receptors?
Protection from dust, smoke, noxious fumes
Where are J receptors located?
Within alveolar walls in juxtaposition to pulmonary capillaries
What do J receptors respond too?
Pulmonary oedema, pneumonia
What are the 2 types of neurogenic control and where are they initiated?
Voluntary - in the cerebral cortex
Involuntary - in the brainstem, limbic system and hypothalamus
What do voluntary neurones control?
Conscious breathing
What do involuntary neurones control and why do they involve limbic system and hypothalamus?
Breathing during sleep
Limbic system = emotional response
Hypothalamus = temperature regulation
What do both neural controls require?
intact innervation to respiratory muscles - descending pathways and LMN (alppha-motoneurone)
Where is the respiratory centre?
Medulla
What does respiratory centre generate?
Rhythmic breathing
What 2 groups of neurones make up the medullary breathing centre?
Dorsal respiratory group - inspiratory drive
Ventral respiratory group - expiratory drive
