During inspiration (inhaling air) ___________

During exercise, there is an increased blood flow to which of the following tissues. Mark all the correct answers. 

The pacemaker of the heart _______

Blood at the venous end of a typical capillary in the tissues of the human body _________

Ulcers have been most directly linked to __________

The respiratory center is very sensitive to changes in ________________ levels, but not very sensitive to changes in __________________ levels.

Select the vessel carrying blood with a comparatively high concentration of oxygen.

Neurons signal to each other. If a stimulus in increasing (e.g. the temperature is increasing) a neuron would convey this information to the brain (or ganglia) by __________

The esophagus contains muscles that allow you to move food towards the stomach. The movement is referred to as _____

In humans the circulatory system serves all of the body systems by [choose all that apply]