BIOL-242 Study Guide - Midterm Guide: Tunica Intima, Tunica Externa, Vasa Vasorum

49 views4 pages

Document Summary

Arteries: blood vessels carrying oxygen-rich blood away from the heart; oxygenated except for pulmonary circulation and umbilical vessels of fetus. Branch into smaller and smaller divisions as they leave. Capillaries: the only blood vessels with intimate contact with tissue cells and directly serve cellular needs. Gossamer-thin capillary walls allow for direct exchange between blood and tissue cells. Veins: blood vessels that carry oxygen-low blood back toward the heart. Converge into successively larger vessels approaching the heart. Tunica intima // innermost tunic, intimate contact with the blood in lumen. Endothelium // tunica intima contains the endothelium, simply squamous epithelium that lines the lumen of blood vessels. Tunica media // middle tunic, bulkiest layer, maintain blood pressure and circulation. Smooth muscle cells and sheets of elastin, regulated by sympathetic vasomotor nerve fibers of the autonomic nervous system. Regulation causes either vasoconstriction (lumen smaller, smooth muscle contracts) or vasodilation (lumen increases, smooth muscle relaxes) Tunica externa // outermost layer of vessel wall.

Get access

Grade+20% off
$8 USD/m$10 USD/m
Billed $96 USD annually
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
40 Verified Answers

Related Documents

Related Questions