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

Elastic (conducting) arteries: includes aorta and branching arteries thick-walled, large-diameter arteries near heart; highest proportion of elastin: smooth out pressure fluctuations; recoil helps maintain pressure & flow of blood, 2. Muscular (distributing) arteries: deliver blood to specific organs (0. 3mm-1 cm diameter, more smooth muscle vs elastin consequences, 3. Arterioles: 10 um to 0. 3 mm diameter; tunica media primarily smooth muscle; a single layer in smallest arterioles, arterioles determine which capillary beds flushed, minute-to-minute, 3 types of capillaries, walls only a thin tunica intima, 1. Continuous capillaries: skin & muscle; uninterrupted lining intercellular clefts allow limited length = ~1 mm; lumen diameter = 8-10 um function = exchange passage of fluids, small solutes. Fenestrated capillaries: similar but endothelial cells riddled with pores (fenestrations) increased permeability to fluids/small solutes, small intestine, endocrine organs, kidney, 3. Venules: 8-100 um diameter; post capillary venules = just endothelium + a few channel fibroblasts; larger venules have sparse tunica media & thin tunica adventitia, 2.