Smooth muscle
The Arteries
The smooth muscle type is associated with blood vessels. This muscle type is involuntary.
The coronary arteries are the blood vessels that bring oxygenated blood to the muscle of the heart.
Blood vessels are surrounded by smooth muscle. This is often known as visceral muscle. This type of muscle also lines the blood vessels and internal organs.
Vasospasm-- Narrowing of a blood vessel caused by a spasm of the smooth muscle of the vessel wall.
Tunica interna
Coronary arteries
vasoconstriction
an increase in vessel diamete
270 ml/min!
Veins
Smooth muscle is mostly in the afferent branch going from the arteries to the arterioles. The body controls where blood will flow by controlling the vessel diameter. An increase in sympathetic tone constricts smooth muscle, decreases blood vessel diameter, and limits blood flow.