Biological Systems MCAT Practice Exam

Which part of the nervous system is characterized by involuntary control of smooth muscle and glands?

1. Somatic nervous system

2. Sympathetic nervous system

3. Autonomic nervous system

4. Centrally coordinated system

The correct answer is: Autonomic nervous system

The autonomic nervous system is responsible for involuntary control of smooth muscle and glands, making it essential for regulating bodily functions that occur without conscious effort. This system controls various involuntary physiological processes, such as heart rate, digestion, respiratory rate, and glandular secretions. It is divided into two main branches: the sympathetic nervous system, which prepares the body for "fight or flight" responses, and the parasympathetic nervous system, which promotes "rest and digest" activities. This dual control allows the body to maintain homeostasis by appropriately responding to changing internal and external environments. In contrast, the somatic nervous system primarily governs voluntary movements by controlling skeletal muscles. The centrally coordinated system is not a recognized component of the nervous system and does not pertain to the control of involuntary functions. Thus, the characterization of the autonomic nervous system accurately reflects its role in managing involuntary actions, distinguishing it from the other components of the nervous system.