Circulatory System Blood Flow
Blood Flow - Like water down a country stream it has it’s own ecosystem. Arteries carry blood away from the heart towards capillaries and have thicker muscular walls than veins do. It’s necessary for them so that the pressure of the blood moving out of the heart does not rupture from use. Veins on the other hand carry blood towards the heart and away from capillaries. The capillaries some only 1 cell thick carry blood from arterioles to venules. The aorta the largest of the arteries carries blood out of the left side of the heart or left ventricle of the heart.
Vena cavae returns blood to the right atrium after the blood has circulated throughout the body. There are three (3) coats of arteries and veins these are the walls of the lumen. Tunica intima, Tunica media, and tunica advenita. Tunica advenita is the outer layer of arteries and veins which is made up of connective fibers that reinforce the wall of the vessels. The middle layer of arteries and veins is made up of smooth muscle tissue. The Tunica media is a layer that also includes a thin layer of elastic fibrous tissue so it can bounce back after use. The tunica intima or inner layer of arteries and veins made up of a single layer of squamous epithelial cells. This single layer of squamous epithelial cells in the tunica intima is called the junica endothelium intima.
Veins are the vessels that have one-way valves in the lunmen as a pulse, or what you feel when placing fingertips over an artery that lies near the surface of the body and over a bone or other firm base, runs through these vessels. When an artery expands and then recoils you can feel this if touching one of the several possible areas of the body is called the radial pulse. Is often used by nurses to make a quick assessment of patients heart beat.
