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In a normal person, when a muscle tendon is tapped briskly, the muscle immediately contracts due to a two-neuron reflex arc involving the spinal or brainstem segment that innervates the muscle. The afferent neuron whose cell body lies in a dorsal root ganglion innervates the muscle or Golgi tendon organ associated with the muscles; the efferent neuron is an alpha motoneuron in the anterior horn of the cord. The cerebral cortex and a number of brainstem nuclei exert influence over the sensory input of the muscle spindles by means of the gamma motoneurons that are located in the anterior horn; these neurons supply a set of muscle fibers that control the length of the muscle spindle itself. Hyporeflexia is an absent or diminished response to tapping. It usually indicates a disease that involves one or more of the components of the two-neuron reflex arc itself. Hyperreflexia refers to hyperactive or repeating (clonic) reflexes. These usually indicate an interruption of corticospinal and other descending pathways that influence the reflex arc due to a suprasegmental lesion, that is, a lesion above the level of the spinal reflex pathways.
Patient Greg Grindley communicates with host Bryant Gumbel and his wife for the first time while undergoing deep brain stimulation surgery at University Hospital's Case Medical Center in Cleveland, Ohio.
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Greg's First In-Surgery Conversation | Brain Surgery Live
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Robotic-assisted endoscopic thyroid surgery using the daVinci® Surgical System can safely and effectively offer those needing thyroid surgery relief without neck incisions. Dr. Ron Kuppersmith and Dr. Andrew deJong are now performing this procedure at the College Station Medical Center in Texas.
This is part 2 Herbal Medicine. Lecture presented to the International Congress of Pediatric Hepatology Sharm 2009. It is one of a series of lectures discussing the Alternative medicine practices with critical appraisal and measure the evidence.