Central chemoreceptors - wikipedia Central chemoreceptors Central chemoreceptors of the central nervous system, located on the ventrolateral medullary surface in the vicinity of the exit of the 9th and 10th cranial nerves, are sensitive to the pH of their environment. These act to detect the changes in pH of nearby cerebrospinal fluid ( CSF ) that are indicative of altered oxygen or carbon dioxide concentrations available to brain tissues. An increase in carbon dioxide causes tension of the arteries, often resulting from decreased CO output ( hypercapnia ), indirectly causes the blood to become more acidic ; the cerebrospinal fluid pH is closely comparable to plasma, as carbon dioxide easily diffuses across the blood -- brain barrier. However, a change in plasma pH alone will not stimulate central chemoreceptors as H+ are not able to diffuse across the blood -- brain barrier into the CSF. Only CO levels affect this as it can diffuse across, reacting with H O to form carbonic acid and thus decrease pH. Central chemoreception remains, in this way, distinct from peripheral chemoreceptors. The central chemoreception system has also been shown experimentally to respond to hypercapnic hypoxia ( elevated CO, decreased O ) and aqueous sodium cyanide injection into the whole animal and in vitro slice preparation. These methods can be used to mimic some forms of hypoxic hypoxia and they are currently being studied including the detection of variation in arterial CO tension acting as a quick - response - system for short term ( or emergency ) regulation. This system utilizes a negative feedback system, therefore if the pH of the cerebral spinal fluid does not compare to an ideal `` set '' level, then the receptor will send an error signal to the effectors and appropriate action may be executed. Peripheral chemoreceptors ( carotid and aortic bodies ) and central chemoreceptors ( medullary neurons ) primarily function to regulate respiratory activity. This is an important mechanism for maintaining arterial blood pO2, pCO2, and pH within appropriate physiological ranges. For example, a fall in arterial pO2 ( hypoxemia ) or an increase in arterial pCO2 ( hypercapnia ) leads to an increase in the rate and depth of respiration through activation of the chemoreceptor reflex. Chemoreceptor activity, however, also affects cardiovascular function either directly ( by interacting with medullary vasomotor centers ) or indirectly ( via altered pulmonary stretch receptor activity ). Respiratory arrest and circulatory shock ( these conditions decrease arterial pO2 and pH, and increase arterial pCO2 ) dramatically increase chemoreceptor activity leading to enhanced sympathetic outflow to the heart and vasculature via activation of the vasomotor center in the medulla. See also Chemoreceptors Peripheral chemoreceptors Vasomotor center References Jump up ^ Solomon IC, Edelman NH, Neubauer, JA. Pre-Bötzinger complex functions as a central hypoxia chemosensor for respiration in vivo. J Neurophysiol. 83 ( 5 ) : 2854 - 68, 2000. External links Physiology : 4 / 4ch6 / s4ch6_21 - Essentials of Human Physiology Overview at cvphysiology.com Respiratory physiology Respiration breath inhalation exhalation respiratory rate respirometer pulmonary surfactant compliance elastic recoil hysteresivity airway resistance bronchial hyperresponsiveness constriction dilatation mechanical ventilation Control pons pneumotaxic center apneustic center medulla dorsal respiratory group ventral respiratory group chemoreceptors central peripheral pulmonary stretch receptors Hering -- Breuer reflex Lung volumes VC FRC Vt dead space CC PEF calculations respiratory minute volume FEV1 / FVC ratio Lung function tests spirometry body plethysmography peak flow meter nitrogen washout Circulation pulmonary circulation hypoxic pulmonary vasoconstriction pulmonary shunt Interactions ventilation ( V ) Perfusion ( Q ) Ventilation / perfusion ratio V / Q scan zones of the lung gas exchange pulmonary gas pressures alveolar gas equation alveolar -- arterial gradient hemoglobin oxygen -- haemoglobin dissociation curve ( Oxygen saturation 2, 3 - BPG Bohr effect Haldane effect ) carbonic anhydrase ( chloride shift ) oxyhemoglobin respiratory quotient arterial blood gas diffusion capacity ( DLCO ) Insufficiency high altitude oxygen toxicity hypoxia Retrieved from `` https://en.wikipedia.org/w/index.php?title=Central_chemoreceptors&oldid=833940592 '' Categories : Sensory receptors Respiratory physiology Talk About Wikipedia Add links This page was last edited on 3 April 2018, at 03 : 26 ( UTC ). Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: the ventilatory central chemoreceptors respond to changes in the
Answer: the pH of their environment