The part of the human brain where the main respiratory center is located is:

The respiratory center in humans can be primarily stimulated by:
1. carbon dioxide and hydrogen ions
2. oxygen gas levels in the blood
3. oxygen gas levels in the hemoglobin
4. conscious feeling for the need for more oxygen

The peripheral chemoreceptors in carotid and aortic bodies respond to:
1. hydrogen ion concentration.
2. levels of carbon dioxide in the blood.
3. levels of oxygen in the blood.
4. all of the above

What will happern to the rate and depth of breathing when blood carbon dioxide rises?

Pneumotaxic center:

The peripheral chemoreceptors are:
1. more sensitive to a decrease in ${\mathrm{PCO}}_2$ than to a decrease in ${\mathrm{PO}}_2$
2. stimulated by hypocapnia
3. located in the medulla oblongata of the brain stem
4. more sensitive to a decrease in ${\mathrm{PO}}_2$ than to a decrease in ${\mathrm{PCO}}_2$