Many students ask where the neurogenic shaking comes from. It is linked to the autonomic nervous system, The autonomic nervous system is responsible for the involuntary control of internal organs. It forms a widespread network of nerves throughout the body that regulates unconscious physiological processes.

The autonomic nervous system controls:

• Smooth muscle (e.g., blood vessels, gut wall, urinary bladder)
• Cardiac muscle
• Glands (e.g., sweat glands, salivary glands)

The ANS has two major divisions:

• Sympathetic (supports activation and mobilization)
• Parasympathetic (supports recovery and restorations)
• Enteric nervous system (controls the gastrointestinal tract)

Fig1; Fig 2. : Sympathetic and Parasympathetic divisions.

Autonomic nerves release neurotransmitters such as acetylcholine and epinephrine. These signals generate action potentials that initiate muscle contraction.

In addition to neural input, smooth and cardiac muscle can contract in response to hormones, pacemaker cells, pharmacological agents, or mechanical stretch.