Control Of Respiration Flashcards
What do control mechanisms participate in?
Establishing automatic rhythm for respiratory muscle contraction
Adjusting rhythm
How is rhythm adjusted?
Changes in metabolic needs (blood PO2, PCO2, pH)
Mechanical conditions (posture change)
Nonventilatory activities (speech, eating, thermoreg,etc. )
What are the different respiratory levels of control?
Respiratory center
Chemoreceptors (central and peripheral)
Proprioceptors
Respiratory center
Pattern generator in medulla influenced by higher centers and inputs from periphery
Vagus nerve
Fine tunes ventilation
Cutting vagus increases TV
Motor neurons
Originate in Brainstem
Innervate respiratory muscles (diaphragm, intercostals, accessory muscles)
Establish an rhythmicity
What are PRGs involved in?
Pneumotaxis and apneusis
Dorsal respiratory group (DRG) and VRGs
Neurons primarily inspiratory while the VRGs are primarily expiratory
Stretch receptors
Pulmonary and airway receptors
Muscle spindle stretch receptors
Pulmonary and airway receptors
Slowly adapting stretch receptors
C-fibers (Juxtacapillary receptors)
Muscle spindle stretch receptors
Monitor stretch of contraction of resp. muscles
More abundant I’m intercostals than in diaphragm
Chemoreceptors
Detects levels of O2 and CO2
2 types: peripheral (@ carotid and atomic bodies) and central (medullary)
Peripheral chemoreceptors
Monitor PaO2, PaCO2, and H+ levels
Their removal eliminates resp. response to hypoxia
Detects acute increases in CSF
Cells in peripheral chemoreceptors
Glomus: type 1, chemoreceptor
Sustentacular: type 2, supportive role
Carotid body neural output occurs within ___________ of onset of hypoxia
1 to 3 seconds
