Respiratory Control Flashcards
what are the 5 major Medullary respiratory centers
DRG: Dorsal respiratory group
-part of nucleus solitaris tractus
VRG: Ventral respiratory group
-contains nucleus ambiguus and dorsal motor nucleus of Vagus
PRG: Pontine respiratory nucleus
-parabrachial nuclei, colorcofuse nuclei
Botzinger complex
-retrofacial nucleus
Pre-Botxinger Complex
Pre-Botzinger complex function
is believed to be the site which generates the timing (frequency) of the respiratory rhythm
more noticeable in babies and gets more complicated the more we get older
More for inspiration since expiration is passive
when does the phrenic nerve fire
Fires during inspiration (activating muscles)
quiet during expiration
Apneusis
failure to turn off inspiration
lesion in the PRG makes it so the Phrenic nerve is constantly firing leaving the body stuck in inspiration
hard to notice this
slight delay, but then increase in CO2, decrease in O2, death if not supported
what is the function of the Pontine respiratory group
important in turning respiration off, part of the network that controls the length of inspiration under normal circumstances
what is the function of the Dorsal respiratory group
DRG (found dorsal, and at the midline by the CN X, and XII
95 percent premotor to phrenic
-recieves lots of sensory info
-Allows it to generate a pattern appropriate to the circumstances in determining the depth (pattern) of the breath (Vt)
what is the function of the Ventral respiratory group
found more lateral and ventrally
Rostral part: premotor to phrenic and most to inspiratory muscles
Caudal part: premotor to upper airway and other muscles of expiration (most muscles of expiration are passive except in the upper airway)
important in the depth of the breath (Vt)
Apnea
apsence of respiratory effect (no inspiration)
damage to the medullary or spinal damage
instant increase in CO2 and decrease in O2, and death if not supported
function of a chemoreceptor and what they respond too
since normal neurons will turn off in an hypoxic event, need a neuron that will fire under certain bad circumstances to continue the respiratory cycle (kick in the but)
the chemoreceptors fire for an increase in CO2, decrease in O2 and a increase in H+
-hypercapnia, hypoxia
what are the two sets of chemoreceptors and where are they located
Central chemoreceptors: In brain
Peripheral chemoreceptors: in carotid and aorta
Central chemoreceptor function
located on ventral surface of medulla
sensitivity indirectly to CO2 in blood
- CO2 will cross BBB
- CO2 reacts with water (Carbonic anhydrase) (making H+ and HCO3-)
due to the decrease in pH (directly activates) this will activate the chemoreceptor
this will give the drive to breath sensation and make you breath regularly
function of the peripheral chemoreceptors
found in carotid body and aortic arch
sensitive to decrease in O2
increase in CO2
increase in H+
(seperate cells in the body controls this)
send signal to the Pre-BotC and stimulate increased Frequency of breathing and Tidal volume
Peripheral chemoreceptors are faster than the Central
what is the Neurotransmitter that the peripheral chemorecepter uses
Dopamine
Location, What are they sensitive to, influence, and effects: Central Chemoreceptor
Location: Ventral surface of brainstem
What are they sensitive to: Directly: pH of CSF
indirectly: CO2 in plasma
Influence: respiratory drive or drive to breathe
Effects: increase respiratory rate/depth in response to hypercapnia (slower than peripheral)
Location, What are they sensitive to, influence, and effects: Peripheral chemoreceptors
Location: aortic arch and carotid body
what are they sensitive to: Directly: O2, CO2, and H+ (pH)
Influence: acute gas changes in blood
effects: increase respiratory rate/depth in response to hypercapnia, hypoxia or acidosis
Location, and effect of the Slowly adapting Pulmonary Stretch receptors
located in airways
sensitive to: stretch of airways directly proportional to lung volume
Fibers travel to brain via Vagus nerve
Effect: inhibition of inspiration (inspiration termination) and prolongation of expiration
-very minimal effect on frequency
what are the circumstances that slowly adapting pulmonary stretch receptors important for controlling respiration in?
Infants: in utero dont want to use the lungs for very long or at all (occurs every breath)
Adults during exercise due to the increased tidal volume
Not too important for adults during rest
location, function of the Rapidly adapting pulmonary stretch receptors
located in airways
sensitive to: irritation, foreign bodies in airway, and stretch
fibers travel to brain in Vagus nerve
Effect: cough much deeper and is not elicted by the larynx, more for influuenza or bronchitis
helps protect the gas exchange surface
protective (not every breath)
what is the function and location of the J (juxtacapillary) receptors
Located near blood vessesl of alveoli
sensitive to Pulmonary edema (lung behaves very stiff and restrictive)
fibers travel to brain via vagus N
Effect: cough, tachypnea
-increased breathing that is fast and shallow
protective (not every breath)
Cortical Influences on breathing
Cortical influences do control breathing as well during talking, or holding breath
cortex will bypass the medullary centers and sending input directly to the muscles of inspiration
