ANP 1105 Lecture Notes - Lecture 20: Tunica Intima, Blood Vessel, Tunica Media

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

Document Summary

Arteries >> arterioles >> capillaries >> venules >> veins: arteries carry blood away from heart, veins carry blood towards heart, only capillaries directly serve cells. Structure of blood vessel walls: tunica intima, tunica media, tunica externa (adventitia) Elastic (conducting) arteries: thick-walled, large diameter, near heart, highest proportion of elastin smooth out pressure uctuatuons, recoil helps maintain pressure and blood ow. Muscular (distributing) arteries: deliever blood to speci c organs, more smooth muscle than elastin. Arterioles: 10 m - 3 mm diameter, tunica media primarily smooth muscle, single layer in smallest arterioles, determine which capillary beds ushed, minute - to - minute. Overview: walls only a thin tunica intima, length 1mm ; lumen diameter = 8-10 m, function: exchange. Microcirculation: flow of blood from an arteriole to a venule through a capillary bed, vascular shunt - metarteriole + thoroughfare channel, true capillaries - actual exhange vessels (10-100/bed) Precapillary sphincter - surrounds root of each true capillary.