Peripheral chemoreceptors, lung receptors

3 Pages
Unlock Document

Colorado State University
Biomedical Science
BMS 420
Charles Miller

5 December Inputs come to medulla (pH, blood gas amounts, temperature, stretch receptors in lungs, &c.) → affect muscles of respiration Pons helps transition between inspiration and expiration Peripheral Chemoreceptors The peripheral chemoreceptors (carotid bodies in carotid arteries or aortic bodies in the aortic arch) are more often studied than the central chemoreceptors because of their accessibility for study. The carotid and aortic bodies respond to decreases in PaO , but 2 not oxygen content, and to increases in PaCO and de2reases in pH. The peripheral chemoreceptors are far less of the ventilatory response than the central chemoreceptors as a result of an increase in carbon dioxide. The type I cells (glomus) contain a rich supply of the neurotransmitter dopamine and are the cells which sense changes in partial pressure of oxygen and carbon dioxide as well as in the pH. Action potentials from these cells are transmitted to the medullary respiratory centers to affect a change in ventilation. Slight increases in alveolar (arterial) PCO ca2se large increases in ventilation AND when hypoxia is present the “ventilatory response to CO ” is e2hanced Trained athletes and divers have a lower ventilatory response to CO 2 The sensitivity to CO i2 reduced with chronic obstructive pulmonary disease (COPD). Action potential in chemoreceptors Inhibition of K channels depolarizes cell, opens Ca channels, triggers dopamine release Response to Oxygen Lack The peripheral chemoreceptors are the only receptors which respond to hypoxia and only when the PaO rea2hes around 60 mm Hg is there much of an increase in ventilation. Again, increased carbon dioxide will augment this reponse. Remember, it is the PaO whi2h drives the chemoreceptors so anemia and carbon monoxide poisoning which decrease the arterial oxygen content do not affect the ventilation response. H changes are sensed by the central chemoreceptors even though H does not cross the blood-brain barrier. The reason that the PCO in th2 CSF is often higher than in the blo
More Less

Related notes for BMS 420

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.