ANP 1105 Lecture Notes - Lecture 8: Tunica Externa, Tunica Media, Blood Vessel

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

Document Summary

Delivery system of dynamic structures that begins and ends at heart: arteries->arterioles->capillaries->venules->veins. Close circuit, starts and ends at heart. Arteries carry blood away from the heart. Artery wall is much thicker than veins, and veins have a larger tube than arteries. Structure of vessels: lumen: central blood-containing space, three wall layers (tunics) in arteries and veins. Tunica intima, tunica media, and tunica externa: capillaries. Endothelium with sparse basal lamina: tunica intima: inner layer (endothelium, subendothelial layer, internal elastic membrane, tunica media: middle layer (smooth muscle and elastic fibers) and changes from vessel to vessel. Smooth muscles may be innovative by the autonomic nervous system: tunica adventitia (externa): outer layer (collagen fibers) and has its own blood supply, provides structure and protection. Elastic (conducting arteries: thick-walled, large-diameter arteries near heart; high proportion of elastin, aorta and its major branches, smooth out pressure fluctuation; recoil helps maintin pressure and flow of blood.