The pharyngeal reflex or gag reflex is elicited by stimulating the posterior pharyngeal wall and results in bilateral contraction of the pharyngeal muscles and brief elevation of the soft palate….

Muscle Stretch Reflex. Parts A and B show some of the connections made by groups Ia and II (not shown) afferent fibers from muscle spindle receptors. These afferent fibers are…

The fibers of the ventral cochlear nucleus then project to the superior olive located in the medulla. The fibers then project by way of the lateral lemniscus nuclei and other…

Centrifugal auditory pathways also include efferent projections to the sensory hair cells of the cochlea and to the muscles of the middle ear. The cochlear efferent fibers originate from a…

NEUROLOGIC DEFICITS Eye movement disorders from brainstem involvement of the pathways subserving horizontal and vertical gaze are usually exquisitely localizing. For example, a lesion in the right abducens nucleus will…

The deeper collicular layers are the source of several efferent projections. One group of fibers crosses the midline and runs caudally, sending terminals to the brainstem reticular formation and then…

DISORDERS OF THE HYPOGLOSSAL NUCLEUS AND NERVE Supranuclear lesions affecting the corticobulbar fibers above their decussation result in weakness of the contralateral half of the tongue. Bilateral upper motor neuron…