BIOL 252 Lecture Notes - Lecture 1: Simple Squamous Epithelium, Basal Lamina, Sympathetic Nervous System
Document Summary
Endothelium: simple squamous epithelium that is a continuation of the endocardium. Internal elastic lamina: provides disntesibility (ability to stretch) and elasticity (recoil) Smooth muscle cells: control diameter of vessel and a mount of blood the ows through. Dense irregular collagenous connective tissue that prevents overstretching. Vasa vasera: provides oxygen and nutrients to outer tunics of blood vessels. Arteries have circular shape, and veins are more elongated (like ovals) Blood ow: arteries --> capillaries--> capillary bed --> venules--> veins. Valves in veins: help the one way ow of blood. Capillary exchange of nutrients or waste products occurs in capillary beds. Fenestrations within capillaries allow di usion of molecules such as glucose into the tissue by concentration gradient. Capillaries have gap junctions, so that they are leaky. There are pre capillary sphincters that connect the arteries to the venues and will regulate whether blood is able to.
