GNUR 293- Exam 4 Review.

GNUR 293- Exam 4 Review/GNUR 293- Exam 4 Review. Respiratory Function and Alterations in Gas Exchange How do central and peripheral chemoreceptors affect breathing? Central chemoreceptors are located in the medullary center and respond to changes in CO2 and pH. This is our NORMAL stimulus to breathe and is caused by a small increase in arterial carbon dioxide tension. This small increase in PaCO2 tells the body to BREATHE. Peripheral chemoreceptors are located in the aortic arch and carotid bodies. They respond to a decrease in PaO2 (arterial oxygen level). They also respond to increases in hydrogen ion concentration (decreased pH) and to increases in arterial carbon dioxide levels (PaCO2). Patients may lose the normal sense to breathe from central chemoreceptors when they have conditions like COPD and retain a LOT of CO2. They’re body has adapted to the chronic acidosis, so chemoreceptors no longer response. Without the stimulus to breathe from central chemoreceptors, the stimulus to breath will now be hypoxemia because the peripheral chemoreceptors in the aortic arch will respond to a decrease in arterial oxygen (hypoxemia) and THIS will stimulate the person to take a breath; this is called the HYPOXIC DRIVE.