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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.
Patent ductus arteriosus (PDA), in which there is a persistent communication between the descending thoracic aorta and the pulmonary artery that results from failure of normal physiologic closure of the fetal ductus (see image below), is one of the more common congenital heart defects.
Posterior dislocations with associated fractures, also known as complex posterior dislocations, often require open reduction and fixation (ORIF). These dislocations are often associated with significant ligamentous injury. In some cases, complex posterior elbow dislocations may be managed with closed reduction. Posterior elbow dislocations that are neglected, as is not uncommon in developing countries, can often be effectively treated with open reduction. [9] Delayed vascular compromise is an important complication after reduction. All patients should be observed for a period of approximately 2-3 hours after reduction. If no evidence of vascular compromise arises, patients can be sent home with appropriate follow-up and instructions to watch for further problems.
Supraventricular tachycardia (SVT) is an abnormal condition of heart which increases normal heartbeat rate rapidly. Normally, heartbeat rate should be between 80 to 100 beats per minute. For more info: https://goo.gl/14btbU
Pregnancy occurs when an egg is fertilized by a sperm, grows inside a woman's uterus (womb), and develops into a baby. In humans, this process takes about 264 days from the date of fertilization of the egg, but the obstetrician will date the pregnancy from the first day of the last menstrual period (280 days 40 weeks).
ACL tears are treatable using arthroscopy and minimally-invasive surgical techniques. The surgical success rates for ACL reconstruction exceed 95%. The anterior cruciate ligament is one of the major supportive ligaments in the knee