CAS BI 106 Lecture Notes - Lecture 21: Tunica Intima, Tunica Externa, Simple Squamous Epithelium
Document Summary
Three main types: arteries, away from heart, cappilaries, very small vessels. Where exchange can happen from the interstitial fluid to the inside: diffusion can occur across them easily, veins, returning to heart. Vessel terminology: anastomosis: 2 or more arteries converge to feed the same body region, often an artery travels along side the vein that drains the same region. If no anastomoses the single artery is called an end artery called companion vessels: lumen: the hollow center of any structure in the body. Anatomy of vessels: both arteries and veins have 3 layers (tunics, outside to in: tunica externa, media, and intima. Tunica intima (endothelium: the innermost layer of a blood vessel, made up of an endothelium (simple squamous epithelium with a basement membrane) and connective tissue. Innermost lining of every single blood vessel everywhere: continuous with endocardium, continuous in all blood vessels. Inside of the heart: never changes size.
