MCQ Detailed View

The autonomic nervous system (ANS) is a part of the peripheral nervous system that regulates involuntary body functions. It controls activities that occur without conscious effort, such as heartbeat, digestion, breathing rate, and glandular secretions. The ANS primarily innervates smooth muscles, cardiac muscles, and glands.

Skeletal muscles, on the other hand, are controlled by the somatic nervous system, not the autonomic system. The somatic nervous system allows voluntary control over skeletal muscles, enabling us to perform actions like walking, lifting objects, and speaking. These muscles respond to direct signals from the brain via motor neurons, not from the autonomic pathways.

The autonomic nervous system is divided into two main branches:

1. 
   

   Sympathetic nervous system: Prepares the body for "fight or flight" responses by increasing heart rate, dilating airways, and redirecting blood flow to essential organs.

   
   


2. 
   

   Parasympathetic nervous system: Maintains "rest and digest" activities, such as lowering heart rate and stimulating digestion.

   
   

The cardiac muscles (heart) and smooth muscles (found in the walls of organs like the stomach, intestines, and blood vessels) are involuntary muscles, meaning they work automatically under the control of the ANS.

Skeletal muscles, despite being muscles, do not fall under the control of the autonomic nervous system because they require voluntary input. The ANS does not innervate them; instead, they are managed by conscious nerve signals.

Therefore, the correct answer is Skeletal muscles, as they are not regulated by the autonomic nervous system but by the somatic nervous system instead.