Neurology | Descending Tracts: Corticospinal Tract скачать в хорошем качестве

Neurology | Descending Tracts: Corticospinal Tract

Official Ninja Nerd Website: https://ninjanerd.org Ninja Nerds! In this lecture, Professor Zach Murphy delivers a comprehensive breakdown of the corticospinal tract, the primary descending motor pathway responsible for voluntary movement of the trunk and limbs. We begin with its origin in the primary motor cortex, premotor cortex, and supplementary motor areas, where upper motor neuron cell bodies initiate motor commands. These axons converge through the corona radiata into the posterior limb of the internal capsule, travel through the cerebral peduncles of the midbrain, descend through the ventral pons, and enter the medullary pyramids. The discussion then focuses on the anatomical distinction between the lateral and anterior corticospinal tracts. At the medullary pyramids, approximately 85–90% of fibers decussate in the pyramidal decussation to form the lateral corticospinal tract, which controls fine, skilled movements of the distal limbs. The remaining fibers continue ipsilaterally as the anterior corticospinal tract, primarily influencing axial and proximal muscles. Once in the spinal cord, upper motor neuron axons synapse on lower motor neurons or interneurons in the ventral horn, which then directly innervate skeletal muscles. We also explore the corticospinal tract's functional and clinical significance, including how lesions at different points along the pathway produce characteristic upper motor neuron signs such as spasticity, hyperreflexia, and the Babinski sign. The lecture emphasizes the importance of understanding decussation and tract location for accurate neurological localization. Enjoy the lecture and support us below! 🌐 Official Links Website: https://www.ninjanerd.org Podcast: https://podcast.ninjanerd.org Store: https://merch.ninjanerd.org 📱 Social Media   / ninjanerdlectures     / ninjanerdlectures     / ninjanerdlectures   https://x.com/ninjanerdsci/   / ninja-nerd   💬 Join Our Community Discord:   / discord   #ninjanerd #CorticospinalTract #DescendingTracts