Physio 4 Flashcards
what are the mechanisms for regulation of respiration
neural and chemical
what are the neural mechanisms of regulation and by what
voluntary by cerebral cortex
involuntary by brainstem ( pons and medulla)
what is the chemical regulation and by what
monitor o2 and co2 levels
by central and peripheral chemoreceptor
what is the neural automatic mechanism to establish a rhythmic breathing pattern
medullary respiratory center
what centers are present in medullary respiratory center
Dorsal respiratory group (DRG)
Ventral respiratory group (VRG)
Pneumotaxic center
what does the ventral respiratory group responsible for (charac)
inspiratory and expiratory neurons
inactive during quiet breathing
active during active / forced respiration
stimulate expiratory signals to abdominal muscles
what does the dorsal respiratory group responsible for (charac)
inspiratory neurons only
dormant during expiration
pacemaker
stimulate inspiratory muscles
what does the pneumotaxic centern responsible for (charac)
sends impulses to DRG to switch off inspiratory neurons
control switch off point of inspiratory ramp so control duration of filling phase of lung cycle
pneumotaxic signal strong
inspiration last for 0.5 sec so filling the lungs slightly
pneumotaxic signal is weak
inspiration lasts for 5 sec so filling the lungs with excess air
where is the chemosensitive area of respiratory center
beneath ventral surface of medulla
what is the chemosensitive area sensitive to
changes in co2 and H+ ( h+ indirect and less effect)
what is the respiratory reflex
rapid automatic adjustment in pulmonary ventilation
baroreceptor, stretch, chemoreceptor, irritating and others
what is the stretch receptor
located in muscular portion of bronchi and bronchiole and it responds to changes in lung volume and send signals through vagus nerve to DRG
What is the feedback response of stretch receptor
decrease inspiration when lung overinflated
where is the central and peripheral chemoreceptors
central in medulla oblongata
peripheral in carotid and aortic arteries