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Mental activities
Published in Karl H.E. Kroemer, Fitting the Human, 2017
Between pairs of vertebrae, two nerve bundles emerge (looking like roots) from the spinal nerve, as Figure 9.3 shows. Displaced vertebrae and material from a ruptured disk can impinge on the spinal nerve extensions with dire consequences for efferent and afferent signals. Wounding a motor nerve may cause weakness, even paralysis of the muscle it serves. Damage to a sensory nerve can lead to feedback of pain and numbness that, in certain cases, may mislead the brain. For example, pain may seem to come from body sections such as the buttocks and the thighs, which are innervated by the sciatic nerve; but the problem might not be there but at the point of impingement of the sciatic nerve at the spinal column. Neurons
A computational model of upper airway respiratory function with muscular coupling
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Olusegun J. Ilegbusi, Don Nadun S. Kuruppumullage, Matthew Schiefer, Kingman P. Strohl
For the genioglossus (the major upper airway dilator muscle), we assumed that muscle contraction occurred for 3s along an anterior-posterior direction. The strength of the contraction was induced through a time-force function in the FE model. In reality, the contraction of muscle tissues is activated through impulses delivered through the motor nerve network, for instance, the hypoglossal nerve for genioglossus in the tongue (Eisele et al. 1997; Yoo and Durand 2005). Figure 3 shows the activation profile used in this study. The activation duration was chosen to mirror a typical neurostimulation procedure. The magnitude of the force at this stage was chosen through preliminary simulations with varying forces until a profile produced airway openings at the epiglottis level typically observed in trial applications of neurostimulation. The activation profile was used as a distributed load within the region of genioglossus muscle. We assumed the airway structure was initially at rest. Therefore, there was no activation for the first 3s of the simulation in order to allow the airway structure to reach stable condition under gravity in the lateral-posterior direction.