| Question | Answer |
| 3 walls of blood vessles | tunica intima, tunica media, & tunica externa |
| tissue of tunica intima | endothelium-simple squamous epithelium |
| intima media made up of | smooth muscle and elastic fibers. the smooth muscle is controlled by vasomotor nerves-sympathetic nerve fiers |
| tunic eterna (adventitia) made of | connective tissue. it protects reinforce and anchors the vessel to surrounding structures |
| 2.5 to 1 cm in diam. thick walled arteries near the heart. large amts of elastin and less smooth muscle for stretching and continuous blood flow...the conducting vessels | elastic arteries |
| 1 cm to .3 mm in diam. deliver blood to specific body organs...the distribution vessels | muscular arteries |
| smallest arteries .3 mm to 10 micrometers in diam. responsible for the DISTRIBUTION of blood flow to different tissues...the resistance vessels | arterioles |
| hardening or stiffening of arterial walls | arteriosclerosis |
| fatty deposits w/in the arterial walls and causes arteriosclerosis | atherosclerosis |
| average capillary length; average lumen diam | 1 mm; 8-10 micrometers |
| capillary walls made of of | tunica intima only |
| have no capillaries | lens, cornea, cartilage, epithelial layers |
| allow passage of water and small solute particles | intercellular clefts |
| pores | fenestration esp where absorption and secretion occur |
| large lumens and allow passage of large solutes and some blood cells | sinusoids |
| networks of capillaries w/in an organ or tissue | capillary beds aka microciculation |
| rings on capillaries controlled by vasomotor nerves and local chemical factors and control the distribution flow | precapillary sphincters |
| have a very thin tunica media and have thinner walls and larger lumens | veins |
| the smallest veins are called | venules |
| venous system contains about what % of the total blood volume | 65% |
| venous valves provide one way flow of blood and found in the extremeities only T or F | TRUE |
| stretched dilated veins caused by incompetent valves which are damaged by high venous pressures | varicose veins |
| tunica intima only, supported by surrounding tissues | venous sinuses |
| 2 or more arteries supply the same area and are interconnected. provide collateral channels in case the primary artery is blocked; often occur around joints | arterial anastamoses |
| provide alternate routes for blood to return to the heart | venous anastamoses |
