ANP 1105 Chapter Notes - Chapter 17: Tunica Intima, Tunica Externa, Blood Vessel

• School: University of Ottawa
• Department: Anatomy and Physiology
• Course: ANP 1105
• Professor: Jackie Carnegie

Document Summary

Topic 4. 3: blood vessels & hemodynamics (chapter 19) Arteries: carry blood away from the heart (branch, diverge, fork: umbilical cords and pulmonary circulation only areas where de-oxygenated blood carried by artery. Veins: carry blood toward heart (join/merge/converge: only capillaries directly serve cells. 19. 1 most blood vessel walls have three layers. Structure of blood vessel: wall of blood vessels (except smallest)=three tunics (cid:894)(cid:862)(cid:272)o(cid:448)eri(cid:374)gs(cid:863)(cid:895)surrou(cid:374)di(cid:374)g the lu(cid:373)e(cid:374) (cid:894)(cid:271)lood-containing space) Tunica intima (innermost): simple squamous epithelium lining lumen (all vessels), nutrients directly from blood. Flat cells close together, forms slick surface minimizing friction. Larger than 1mm=has sub-endothelial vein: has basement membrane and loose connective tissue supporting endothelium. Tunica media: circularly arranged smooth muscles cells & sheets of elastin (blood pressure & circulation: activity of smooth muscle regulated by sympathetic vasomotor fibers & chemicals. Regulation causes vasoconstriction (lumen diameter , sm contracts), vasodilation (lumen diameter , sm relaxes) Tunica adventitia (externa): composed of loosely woven collagen fibers protecting and reinforcing vessel, anchors to surrounding structures.