BIOL 030 Lecture Notes - Lecture 16: Upper Motor Neuron, Ependyma, Spinal Nerve
17 Sep 2020
School
Department
Course
Professor
Document Summary
Gray matter the central core of the spinal column - looks butterfly or h-shaped in cross section. Anterior (ventral) root of spinal nerve carries only motor fibres. Gray commissure connects right and left sides. Central canal lined with ependymal cells and filled with csf. Bundles of axons up and down the cord providing communication btwn different levels of cns. 3 pairs of columns on each side: Each column consists of subdivisions tracts or fasciculi. Fibres in a given tract have similar origin, destination, and function. Ascending tracts carry sensory information up. Descending tracts carry motor info down. Decussation: crossing of the midline that occurs in many tracts so that brain senses and controls contralateral side of the body (i. e, tracts go left or right or vice) Sensory signals travel across three neurons form origin (receptors) to destinations in the. Detects stimulus and transmits signal to spinal cord or brainstem.
