Now let's focus in on the left ventricle. The left ventricle contains a very thick layer of muscle and that is shown in black. So we have the thickest layer of muscle within the left ventricle as shown. Now that's because it's the ventricle that creates that hydrostatic pressure in the first place that forces all that blood to move into our blood vessel. And the blood vessels that connect directly to the left ventricle are these blood vessels. It's our order which is the largest artery in our body.