Question

What are the roles of chemoreceptors and neural inputs during the control of respiration?

Answer 1

roleof chemoreceptors

chemoreceptors are the sensory cell or organ responsive to chemical stimuli to control respiration

chemoreceptors monitor changes in Pco2 , Po2 and pH

chemoreceptors are centrally-medulla

and peripherally carotid and aortic bodies are located

a)central chemoreceptors

central chemoreceptors of the central nervous system located in the medullary surface in near exit of the 9th and 10th cranial nerves are sensitive to pH

they act to detect the pH near CSF which indicates abnormal level of the carbon dioxide in the brain tissues

more sensitive to changes in arterial Pco2

H2O + CO2 = H+

H+ can't cross the blood brain barrier

CO2 can cross the blood brain barrier and will form H2CO3

H2CO3  will lowers pH of CSF

Directly will stimulates central chemoreceptors

b)Peripheral chemoreceptors

peripheral chemoreceptors response to change in the blood molecule concentration and help to maintain cardiorespiratory homeostasis

are not stimulated directly by changes in arterial Pco2

H2O + Co2 = H2CO3 = H+

Stimulated by the rise in H+ of the arterial blood and increased H+ Stimulates the peripheral chemoreceptors

-neural input during control of respiration

control of respiration is via motor cortex in the cerebrum, which recieves inputs from the limbic system and hypothalamus

generally believed that the breathing rhythm is generated by the neurons in the prebotzinger complex and they have the main neuronal control of the respiration

these neurons display pacemaker activity.

they are located in near upper end of the medullary respiratory centre

they regulate movements of the lungs, airways, and chest wall and abdomen in order to accomplish effective intake of the oxygen and carbon dioxide