ANP 1105 Lecture Notes - Lecture 16: Tunica Externa, Tunica Intima, Tunica Media

• School: University of Ottawa
• Department: Anatomy and Physiology
• Course: ANP 1105
• Professor: Joanne Savory

Document Summary

Anp1105 a dr. joanne savory and dr. m zeroual. Blood vessels: delivery system of dynamic structures that begins and ends at heart. Veins carry blood away from heart; oxygenated. Three wall layers (tunics) in arteries and veins: tunica intima: simple squamous epithelium that lines lumen of all vessels. Subendothelial layer: connective tissue basement membrane: tunica media: mostly smooth muscle and sheets of. Sympathetic vasomotor nerve fibers innervate this layer (vaso constriction and vasodilation: tunica adventitia (externa): mostly of loose collagen fibers; protect and reinforce wall and anchor it to surrounding structures. Vaso vasorum: system of tiny blood vessels found in larger vessels; function to nourish. Infiltrated with nerve fibers, lymphatic vessels outermost external layer. More smooth muscle than elastin: arterioles (resistance vessels) tunica media primarily smooth muscle; a single layer in smallest arterioles. Arterioles determine which capillary beds flushed, minute-to-minute. Resistance arteries b/c changing diameters change resistance to blood flow (10 um to 0. 3mm diameter)