What to propel blood through the vessel shown here? what to propel blood through the vessel shown here? the large size of the lumen contraction of the smooth muscle in the tunica media contraction of surrounding skeletal muscle stretching and recoil of elastic fibers in the vessel wall?

Answer;
Contraction of the smooth muscle in the Tunica media helps propel blood through the vessel shown.

Explanation; 
The Tunica media is the Middle layer of a blood vessel.
It has Smooth muscle that regulates the diameter of the lumen (innervated by the ANS) which regulates blood flow through different parts of the body and blood pressure
Its Elastic fibers allow vessel to stretch and recoil

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