CO2.
From Wikipedia, the free encyclopedia. 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. The central chemoreception system has also been shown experimentally to respond to hypercapnic hypoxia (elevated CO 2, decreased O 2) and aqueous sodium cyanide injection into the whole animal and in vitro slice preparation. The H+ in the blood, however, cannot cross the blood-brain barrier, and thus cannot influence the medullary chemoreceptors. Carbon dioxide in the arterial blood can cross the blood-brain barrier and, through the formation of carbonic acid, can lower the pH of cerebrospinal fluid (fig. 16.30). An increase in blood CO2 stimulates breathing indirectly by lowering the pH of blood and cerebrospinal fluid (CSF). This figure illustrates how a rise in blood CO2 increases the H+ concentration (lowers the pH) of CSF and thereby stimulates chemoreceptor neurons in the medulla oblongata. Direct chemoreceptors are also found in the carotid body, a structure located at the branch of the carotid artery. These nerves detect levels of oxygen and carbon dioxide in the blood to determine when someone needs to breathe. Chemoreceptors are specialized nerve cells which are designed to respond to chemical stimuli. The body contains both direct and distant chemoreceptors, all of which play important roles in bodily function and daily life. There are two main classes of the chemosensor: direct and distance. 1  Examples of distance chemoreceptors are: 2  olfactory receptor neurons in the olfactory system: Olfaction involves the ability to detect chemicals in the gaseous state. Chemoreceptors that regulate the depth and rhythm of breathing are broken down into two categories. 1  central chemoreceptors are located on the ventrolateral surface of medulla oblongata and detect changes in pH of cerebrospinal fluid. 2  peripheral chemoreceptors: consists of aortic and carotid bodies. There are chemoreceptors in the large arteries of the thorax and the neck; called carotid and aortic bodies. These receptors are responsive to changes in the oxygen, carbon dioxide and hydrogen ion concentration in the blood. When oxygen concentration falls below normal in the arterial blood, the chemoreceptors send impulses to stimulate the respiratory center so that there will be an increase in alveolar ventilation, and consequently, an increase in the intake of oxygen by the lungs. All of these nerve cells send impulses back to the brain. Chemoreceptors can also be found in the brain itself, monitoring pH level and alerting the brain to the presence of chemicals which could indicate a problem. Chemoreceptors are specialized nerve cells which are designed to respond to chemical stimuli. The body contains both direct and distant chemoreceptors, all of which play important roles in bodily function and daily life. The chemoreceptors most sensitive to changes in the arterial PCO2 are located in the ventral area of the medulla oblongata, near the exit of the ninth and tenth cranial nerves. An increase in blood CO2 stimulates breathing indirectly by lowering the pH of blood and cerebrospinal fluid (CSF). This figure illustrates how a rise in blood CO2 increases the H+ concentration (lowers the pH) of CSF and thereby stimulates chemoreceptor neurons in the medulla oblongata. 1 Examples of distance chemoreceptors are: 2  olfactory receptor neurons in the olfactory system: Olfaction involves the ability to detect chemicals in the gaseous state. 3  In vertebrates, the olfactory system detects odorants and pheromones in the nasal cavity. Chemoreceptors that regulate the depth and rhythm of breathing are broken down into two categories. 1  central chemoreceptors are located on the ventrolateral surface of medulla oblongata and detect changes in pH of cerebrospinal fluid. 2  peripheral chemoreceptors: consists of aortic and carotid bodies. 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. The central chemoreception system has also been shown experimentally to respond to hypercapnic hypoxia (elevated CO 2, decreased O 2) and aqueous sodium cyanide injection into the whole animal and in vitro slice preparation. A chemoreceptor, also known as chemosensor, is a sensory receptor that transduces a chemical signal into an action potential. In more general terms, a chemosensor detects certain chemical stimuli in the environment. Chemoreceptors that regulate the depth and rhythm of breathing are broken down into two categories. 1  central chemoreceptors are located on the ventrolateral surface of medulla oblongata and detect changes in pH of cerebrospinal fluid. 2  peripheral chemoreceptors: consists of aortic and carotid bodies.
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what stimulates chemoreceptors