The key difference between anterolateral system and dorsal column system is that anterolateral system carries the sensory modalities of crude touch, pain and temperature while dorsal column system carries the sensory modalities of fine touch, vibration and proprioception.
Somatic sensory pathways transmit body sensations of touch, pain, temperature, vibration and proprioception. There are two pathways as anterolateral system and dorsal column system. In anterolateral system, signals ascend the spinal cord via the anterior and lateral spinothalamic tract. Small unmyelinated axons in the anterolateral system carry information about the crude touch, pain and temperature. In dorsal column system, signals ascend the spinal cord via the dorsal columns. Large diamer myelinated axons in dorsal column system carry information about fine touch, vibration and proprioception. Three groups of neurons are involved in two pathways. Both systems transmit conscious sensations.
CONTENTS
1. Overview and Key Difference
2. What is Anterolateral System
3. What is Dorsal Column System
4. Similarities Between Anterolateral System and Dorsal Column System
5. Side by Side Comparison – Anterolateral System and Dorsal Column System in Tabular Form
6. Summary
What is Anterolateral System?
Anterolateral system is one of the somatic sensory pathways that transmit sensations of crude touch, pain and temperature. In this system, signals ascend the spinal cord via the anterior and lateral spinothalamic tracts. Therefore, the anterolateral system consists of two separate tracts as anterior spinothalamic tract and lateral spinothalamic tract. Anterolateral system has three groups of neurons: first, second and third-order neurons. In anterolateral system, smaller diameter and unmyelinated axons carry information about crude touch, pain and temperature.
Figure 01: Ascending Tracts
What is Dorsal Column System?
Dorsal column system is the second somatic sensory pathway. It transmits sensations of vibration, proprioception, and light touch. In this system, signals ascend the spinal cord via dorsal columns. Similar to the anterolateral system, the dorsal column system is composed of three groups of neurons. The larger diameter and myelinated axons transmit information in the dorsal column system. Therefore, signal transmission is rapid in the dorsal column system.
What are the Similarities Between Anterolateral System and Dorsal Column System?
- Both systems are somatic sensory pathways.
- They transmit conscious sensations.
- Both systems convey touch sensation.
- They have three groups of neurons: first, second and third order neurons.
What is the Difference Between Anterolateral System and Dorsal Column System?
Anterolateral system is the somatic sensory pathway that carries the sensations of crude touch, pain and temperature while dorsal column system is the somatic sensory pathway that carries the sensations of fine touch, vibration and proprioception. So, this is the key difference between anterolateral system and dorsal column system. In the anterolateral system, signals ascend the spinal cord via anterior and lateral spinothalamic tracts while in the dorsal column system, signals ascend the spinal cord via the dorsal columns.
The below infographic tables more differences between anterolateral system and dorsal column system.
Summary – Anterolateral System vs Dorsal Column System
Anterolateral system and dorsal column system are two somatic sensory pathways. The anterolateral system conveys the sensations of crude touch, pain and temperature. Meanwhile, the dorsal column system conveys the sensations of fine touch, vibration and proprioception. However, both systems transmit conscious sensations. Also, both are composed of three groups of neurons. But, in the anterolateral system, smaller diameter, unmyelinated axons carry information while in the dorsal column system, larger diameter myelinated axons carry information. So the signal transmission is slow in the anterolateral system while the signal transmission is rapid in the dorsal column system. Thus, this summarizes the difference between anterolateral system and dorsal column system.
Reference:
1. “Somatosensory Pathways.” AccessPhysiotherapy, Available here.
2. “The Ascending Tracts.” TeachMeAnatomy, Available here.
Image Courtesy:
1. “1417 Ascending Pathways of Spinal Cord” By OpenStax College – Anatomy & Physiology, Connexions Web site. Jun 19, 2013 (CC BY 3.0) via Commons Wikimedia