When a cardiac muscle cell is depolarized, the voltage is:

These vessels have a thick tunica media and a small lumen:

These vessels are the site of gas exchange:

Which layer of the heart wall contains cardiac muscle tissue?

The endothelium is a component of which layer of the vessel walls?

Angiotensin 2 can ____________ blood pressure by increasing blood volume.

Which heart chamber has the thickest wall?

This type of pressure drives substances OUT of a vessel:

Generally, planets and moons in our solar system are named after

The 17th century astronomer who kept a roughly 20 year continuous record of the positions of the Sun, Moon, and planets was: