Lateral horns of the spinal cord

Lateral Horns of the Spinal Cord

The lateral horns of the spinal cord are specialized regions found within the gray matter of the spinal cord. They are located in the thoracic and upper lumbar regions of the spinal cord, specifically in the intermediolateral cell column. The lateral horns play a crucial role in the autonomic nervous system (ANS) by housing the cell bodies of preganglionic sympathetic neurons.

Anatomy

The spinal cord is divided into gray and white matter. The gray matter is centrally located and is shaped like a butterfly, while the white matter surrounds the gray matter. The gray matter is further divided into different regions, including the dorsal horns, ventral horns, and lateral horns.

The lateral horns are present only in the thoracic and upper lumbar regions of the spinal cord. They are located in the intermediolateral cell column, which is situated between the dorsal and ventral horns. The intermediolateral cell column extends from the first thoracic (T1) to the second lumbar (L2) spinal segments.

Function

The lateral horns of the spinal cord are primarily involved in the sympathetic division of the autonomic nervous system. The sympathetic division is responsible for the "fight or flight" response, which prepares the body for action in response to stress or danger.

Within the lateral horns, the cell bodies of preganglionic sympathetic neurons are found. These neurons receive input from higher centers in the brain and transmit signals to the sympathetic ganglia located outside the spinal cord. From the ganglia, postganglionic sympathetic neurons extend to various target organs, such as the heart, blood vessels, and sweat glands.

The lateral horns also receive input from sensory neurons that carry information related to visceral sensations. This input helps regulate the activity of the sympathetic division, allowing for appropriate responses to changes in the internal environment of the body.

Clinical Significance

Damage or dysfunction of the lateral horns can lead to various autonomic disorders. For example, damage to the lateral horns in the thoracic region of the spinal cord can result in Horner's syndrome. Horner's syndrome is characterized by a combination of symptoms, including drooping of the eyelid (ptosis), constriction of the pupil (miosis), and decreased sweating on one side of the face.

Additionally, certain diseases, such as spinal cord injuries or neurodegenerative disorders, can affect the function of the lateral horns and disrupt autonomic control. This can lead to problems with blood pressure regulation, body temperature control, and other autonomic functions.

Conclusion

The lateral horns of the spinal cord are essential components of the autonomic nervous system. They house the cell bodies of preganglionic sympathetic neurons and play a crucial role in regulating the "fight or flight" response. Understanding the anatomy and function of the lateral horns helps in comprehending the complex workings of the autonomic nervous system and its impact on overall bodily functions.