resp 7 neural pathways Flashcards
where is breathing initiated
medulla
dorsal&ventral&pontine resp. group
where is breathing modified
higher structures in CNA, chemoreceptor and mechanoreceptor inputs
what kind of neurons are in the ventral respiratory group
PreBötC
pFRG
what do the PreBötC do
generate excitatory inspiratory rhythmic activiry
what do the pFRG do
generate excitatory ACTIVE expiratory rhythmic activity
what must neuronal networks adjust to accomodate (4 things)
metabolic demands (Pco2, H+…)
mechanical conditions (posture)
non-ventilatory behavious (cough)
diseases
what do the rostral VRG PreBötC inervate
phrenic & thoracic, diaphragm and ext. intercostal muscles
what do the rostral VRG & parahypoglossal PreBötC inervate
cranial motor neurons in medulla
tongue and upper airway muscle
what does pFRG caudal VRF innervate
thoracic and lumbar
int. intercostal and ab muscles
what can PreBötC depression cause
respiratory depression
which three conditions increase ventilation (chemical control)
Hypoxia (low PO2), hypercapnia (high PCO2), and acidosis (low pH in blood)
what are chemoreceptors
specialized structures that sense changes in PO2,PCO2 and pH
what do carotid and aortic bodies detect
hypoxia (low Po2) and pH changes
carotid bodies have similar Po2, Pco2 and pH as
the systemic arteries
what does the carotid body’s high profusion allow them to do
detect levels of po2 pco2
what are carotid bodies type 1/ glomus cells do
chemosensitive
what are carotid bodies type 2/ sustentacular cells
support the carotid body
when do carotid body chemoreceptors fire the most
when arterial Po2 is low
why are carotid bodies kinda like neurons
they have voltage gated ion channels that can depolarize, and they have neurotransmitters
when do stimulation of peripheral chemireceptors occur
low PO2 values, like under 60mmHg
where do peripheral chemireceptors activate with hypoxia
what does it cause
dorsal and ventral respiratory group neurons in medulla
increase tidal volume and respiratory rate
does arterial Pco2 or Po2 cause a larger response in regulation
pco2!!
very small changes in pco2 have much larger effects on ventilation change
where in the brainstem are the central chemoreceptors
ventral
close contact to blood vessels and cerebrospinal fluid
what do the central chemoreceptors detect
changes in pH
which leads them to infer Pco2
what is hypoxia
low Po2
what is hypercapnia
high CO2
what is acidosis
low pH in blood
which chemoreceptors are responsible for most of the response to hypercapnia
central chemoreceptors (response to increase H+ in brain extracellular fluid)
does H+ change in metabolic acidosis mostly stimulate peripheral or central and why
peripheral because H+ doesn’t pass the blood brain barrier
