Corticospinal Tract
Published: Jul 16, 2023
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Updated: Jul 23, 2023
Written by Oseh Mathias
Founder, SpeechFit
The corticospinal tract, a component of the central nervous system, plays a critical role in the transmission of motor signals [1]. It is one of the key motor pathways linking the brain to the spinal cord, instrumental in voluntary motor control [2].
In the cerebral cortex, the corticospinal tract's origins can be found. Here, it consists of approximately a third of all cortical neurons [3]. The main contributors to the corticospinal tract are neurons from the primary motor cortex (Brodmann's area 4), premotor areas, and the supplementary motor area [4].
The corticospinal tract can be divided into two primary sections: the lateral corticospinal tract and the anterior corticospinal tract [6].
Approximately 80-90% of the tract's fibers make up the lateral corticospinal tract [7]. At the medulla oblongata level in the brainstem, this tract crosses over (decussates). It then descends through the spinal cord's lateral columns and synapses with interneurons and motor neurons in the ventral horns of the spinal cord [8]. The lateral corticospinal tract primarily controls the limbs and digits [9].
On the other hand, the anterior corticospinal tract houses fibers that do not decussate at the medulla [10]. These fibers descend ipsilaterally through the anterior column of the spinal cord before crossing over at the level they innervate. Subsequently, these fibers synapse with motor neurons in the ventral horn [11]. Primarily, the anterior corticospinal tract governs the axial and proximal muscles, such as the trunk and shoulder muscles [12].
Oseh is a software engineer, entrepreneur and founder of SpeechFit. Oseh is passionate about improving health and wellbeing outcomes for neurodiverse people and healthcare providers alike.
References
Bear, M. F., Connors, B. W., & Paradiso, M. A. (2016). Neuroscience: exploring the brain. Wolters kluwer.
Purves, D., Augustine, G. J., Fitzpatrick, D., Katz, L. C., LaMantia, A. S., McNamara, J. O., & Williams, S. M. (2001). Neuroscience. Sinauer Associates.
Brodal, P. (2016). The central nervous system: structure and function. Oxford University Press, USA.
Kandel, E. R., Schwartz, J. H., Jessell, T. M., Siegelbaum, S. A., & Hudspeth, A. J. (2012). Principles of neural science (Vol. 5). New York: McGraw-hill.
OpenStax College. (2013). Illustration from Anatomy & Physiology, Connexions Web site. Retrieved July 23, 2023, from http://cnx.org/content/col11496/1.6/.
Lemon, R. N. (2008). Descending pathways in motor control. Annual review of neuroscience, 31, 195-218.
Patestas, M. A., & Gartner, L. P. (2009). A textbook of neuroanatomy. Blackwell Publishing.
Martin, J. H. (2005). The corticospinal system: from development to motor control. The Neuroscientist, 11(2), 161-173.
Rizzolatti, G., Luppino, G., & Matelli, M. (1998). The organization of the cortical motor system: new concepts. Electroencephalography and clinical neurophysiology, 106(4), 283-296.
Lawrence, D. G., & Kuypers, H. G. (1968). The functional organization of the motor system in the monkey: I. The effects of bilateral pyramidal lesions. Brain, 91(1), 15-36.
Lemon, R. (2008). Descending pathways in motor control. Annual Review of Neuroscience, 31, 195-218.
Schieber, M. H. (2007). Comparative anatomy and physiology of the corticospinal system. Handbook of clinical neurology, 82, 15-37.