The carotid chemoreceptors are a major determinant of ventilatory CO2 sensitivity and of PaCO2 during eupneic breathing.
Both carotid and intracranial chemoreceptors are critical to a normal ventilatory CO2-H+ chemosensitivity. At low levels of hypercapnia, the carotid contribution is probably greater than the central contribution but, at high levels, the intracranial chemoreceptors are dominant. The carotid chemoreceptors are also critical to maintaining a stable and normal eupneic PaCO2, but lesion-induced attenuation of intracranial CO2-H+ chemosensitivity does not consistently alter eupneic PaCO2. A major unanswered question is why do intracranial chemoreceptors in carotid body denervation (CBD) animals tolerate an acidosis during eupnea which prior to CBD elicits a marked increase in breathing.
Forster
Hubert V
HV
Medical College of Wisconsin, Physiology, USA. bforster@mcw.edu
Martino
Paul
P
Hodges
Matt
M
Krause
Katie
K
Bonis
Josh
J
Davis
Suzanne
S
Pan
L
L
D000818:Animals; D001921:Brain / Q000502:physiology; D002245:Carbon Dioxide / Q000502:physiology*; D002344:Carotid Body / Q000502:physiology* / Q000503:physiopathology; D002628:Chemoreceptor Cells / Q000502:physiology*; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology*; D023421:Models, Animal; D012143:Respiratory Physiological Phenomena
D002245:Carbon Dioxide