Which of the following processes is controlled by the vagus nerve?

• A. Bone remodeling
• B. Gastrointestinal peristalsis
• C. Blood glucose regulation
• D. Muscle contraction

Answer: (B)

The vagus nerve plays a crucial role in the parasympathetic nervous system, which is largely responsible for regulating involuntary bodily functions. One of its primary functions is to control various aspects of the gastrointestinal system, including peristalsis—the wave-like muscle contractions that move food through the digestive tract. The vagus nerve innervates the muscles of the gastrointestinal tract, facilitating digestion by promoting peristalsis and contributing to the secretion of digestive enzymes.

In contrast, processes such as bone remodeling, blood glucose regulation, and muscle contraction involve different systems and mechanisms. Bone remodeling is primarily controlled by hormonal signals and local cellular activities rather than direct neural control. Blood glucose regulation is mainly managed by hormones like insulin and glucagon, which are secreted by the pancreas in response to blood sugar levels. Muscle contraction, while influenced by the nervous system (including peripheral nerves), is more directly activated by motor neurons and does not have direct control by the vagus nerve. Thus, gastrointestinal peristalsis is the process most directly associated with the vagus nerve's activity.