ANATOMY

Detailed explanation-1: -Greater activity of the sympathetic nerve fibres induces higher tension of smooth muscles and thus changes mechanical state of the tissues around the receptors. The latter condition, in its turn, affects the response of receptors to mechanical stimulation.

Detailed explanation-2: -Smooth muscle cells distributed in the visceral organs are under the control of the autonomic nervous system, and contraction or relaxation of the muscle cells plays an important physiological role in the control of blood pressure, motility of the digestive, respiratory and urinary tracts and secretion.

Detailed explanation-3: -Answer and Explanation: Smooth muscles in the digestive system are stimulated to contract by the parasympathetic division, except for arteriole muscles which are stimulated by the sympathetic division to contract.

Detailed explanation-4: -The peripheral nervous system consists of the somatic nervous system (SNS) and the autonomic nervous system (ANS). The SNS consists of motor neurons that stimulate skeletal muscles. In contrast, the ANS consists of motor neurons that control smooth muscles, cardiac muscles, and glands.