HTHSCI 1H06 Chapter Notes - Chapter 14,11: Cuneate Fasciculus, Lateral Corticospinal Tract, Medulla Oblongata
14 Dec 2015
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Document Summary
The brain stem is the part of the brain between the spinal cord and the diencephalon. Three strutures: medulla oblongata, pons, midbrain. Extending through the brain stem is the reticular formation: a netlike region of interspersed gray and white matter. Why does one side of the brain control voluntary movements on the opposite side of the body : decussation: of pyramids decuss = crossing. 90% axons in left pyramid cross to right side. 90% in right pyramid cross to left side. Medullary respiratory center -> adjusts rhythm of breathing nuclei also control reflexes for vomiting, swallowing, sneezing, coughing an hiccupping vomiting center. Deglutition center = swallowing sneezing and hiccupping involve spasmodic contractions of breathing muscles and diaphragm respectively. Nuclei associated with sensations of touch, pressure, vibration, and conscious proprioception are located in the posterior part of the medulla: right and left gracile nucleus slender + cuneate nucleus wedge .
