Respuesta :
The answer is Tunica media. This layer is found between Tunica externa and tunica intima and is the thickest layer. The layer is made up of smooth muscles and extracellular matrix of elastin and collagen. The nerves innervated in the layer are from the sympathetic system that control the vascular tone of the blood vessel.
Tunica media is the blood vessel tunic that is innervated by nerves from the sympathetic nervous system and arteries have thicker tunica media. The tunica media of arterioles contains huge muscle and thus they regulate the blood flow to the delicate capillaries. Tunica media lies between the inside of tunica intima and the outside of tunica externa.