Another important measurement that we have to be familiar with, that describes the way that our blood flows inside blood vessels of our cardiovascular system is a measurement known as the resistance of our blood vessel. Now, in this lecture, we're not only going to focus on resistance, we're also going to discuss the relationship between resistance and something called the volume flow rate of of our blood. So let's begin by describing the factors that influence our resistance of the blood vessel. So we have three different factors that determine the resistance to blood flow in a given blood vessel. So factor number one is the viscosity of our blood, and the viscosity is the internal resistance inside the blood that exists because of the attraction between the molecules and particles themselves that are found within our blood. So the more attraction we have inside the blood between the individual particles, the higher our internal resistance is and the greater our viscosity is.