Arteries possess the ability to grow and remodel in response to sustained alterations in biomechanical loading, likely via mechanisms that are similarly involved in diverse arterial pathologies and responses to treatment. In particular, myriad experminental observations suggest that cell and matrix turnover within vasoaltered states enable arteries to adapt to sustained changes in mechanical stimuli. The goal herein is to show explicitly how altered smooth muscle contractility and matrix growth and remodeling work together to adapt the geometry, structure, stiffness, and function of a representative basilar artery. This work seeks to illustrate the importance of complementary vasoactivity and matrix remodeling for basilar arteries in response to sustained alterations in mechanical stimuli. Toward this end, an extended constrained mixture model of the arterial wall is employed whereby the mass fractions, material properties, and natural configurations of individual constituents can evolve separately and thereby dictate overall growth and remodeling. This approach accounts for fundamentally important behaviors. Simulations provide important intuition and insight regarding constitutive functional forms and model parameters.