Blood vessels are active dynamic organs that are capable of contracting and expanding as they: deliver oxygen and nutrients to cells, carry away waste products, and do their part of maintaining blood pressure (Green, 2015). The three major types of blood vessels are the arteries, the veins and the capillaries. The arteries carry oxygenated blood away from the heart, while the veins carry deoxygenated blood towards the heart and the capillaries act as a branch or pathway between arterioles and venules. Inside the capillaries are arterioles that are mini - arteries that branch out into the capillaries, and venules which are the smallest vein component that can expel blood from capillaries. There are three layers of tissues (tunics) that most blood vessels share that surround the lumen. They are the tunica externa, the tunica media, and the tunica intima. The tunica media plays a key part in blood flow and blood pressure because in the case of vasoconstriction this layers diameter is decreased and in the case of vasodilation the diameter of this layer is increased. The smaller the diameter of the blood vessel, the harder it is for blood to move through it (Green, 2015). Changes in vessel diameter can be temporary like in vasodilation and vasoconstriction, but can also be permanent. When an excess of fatty plaque for example the …show more content…
When the clear unobstructed was placed into the water (at the point where the tape was marked) which was a measured height of 6.3 cm it took little to no effort to create a steady stream of bubbles. However when the obstructed straw was submerged into the water it took more air in order to create a steady stream of bubbles. It was also noticed that the unobstructed straw produced larger bubbles that hit the surface in blobs, unlike the obstructed straw that produced small, tiny bubbles that disappeared whirling to the top of the open