Autonomic Nervous System Divisions Quiz

Sympathetic Nervous System

• Named 'sympathetic' due to its role in preparing the body for stress-related activities, often associated with flight-or-fight responses.
• Sympathetic nerves primarily arise from the thoracic and lumbar sections of the spinal cord (T1-L2).

Autonomic Nervous System Divisions

• The enteric nervous system is a local system located within the wall of the alimentary tract, often referred to as the "second brain."

Components of the Enteric Nervous System

• Composed of two primary plexuses: the myenteric plexus, which regulates gastrointestinal motility, and the submucosal plexus, which controls secretions and blood flow.

Integration and Coordination of Autonomic Functions

• The autonomic nervous system integrates inputs from various sources, including the central nervous system, to ensure coordinated responses among its divisions: sympathetic, parasympathetic, and enteric.

Effects of Sympathetic Nervous System Activity on Eye

• Sympathetic activity leads to dilation of the pupils (mydriasis) to enhance vision in low light conditions.

Effects on Heart and Lungs

• Increases heart rate and force of contraction, enhancing cardiac output.
• Dilates bronchioles in the lungs, allowing increased airflow for better oxygenation.

Effects on Gastrointestinal Tract

• Lowers activity of the gastrointestinal tract, reducing digestive processes during stress responses.

Effects on the Liver

• Stimulates glycogenolysis and gluconeogenesis in the liver, increasing glucose availability for energy during stressful situations.

Effects on Urinary Bladder

• Causes relaxation of the bladder wall and contraction of the sphincters, inhibiting urination during times of stress.

Test your knowledge of the general divisions and functions of the autonomic nervous system, with a focus on the sympathetic nervous system. Explore the activation and components of the sympathetic and parasympathetic nervous systems.