A reflex action, differently known as a reflex, is an involuntary and nearly instantaneous movement in response to a stimulus.
When do reflex and muscle tests indicate nerve damage. Reflexes test neural function. Reflexes may be depressed or exaggerated. When nerve dysfunction exists, the size of the reflex response helps to indentify where the dysfunction originates. These tests help gauge the strength in your leg muscles. They can also help the physician tell if there is nerve damage as the result of a degenerative spinal abnormality. For the reflex test, the physician will gently strike the knee and the back of the heel with a small rubber hammer. All rights reserved. 1  nervous system: The Nervous System and Reflexes-The Nervous System and Reflexes In general, nerve function is dependent on both sensory and motor ... Commonly, the reflex arc includes one or more connector neurons that exert a modulating effect, allowing varying degrees of response, e.g., according to whether the stimulation is strong, weak, or prolonged. Reflex arcs are often linked with other arcs by nerve fibers in the spinal cord. The normal response is a ‘knee jerk’. This is an example of a reflex, which is an involuntary muscular response elicited by the rubber hammer tapping the associated tendon. When reflex responses are absent this could be a clue that the spinal cord, nerve root, peripheral nerve, or muscle has been damaged. When reflex response is abnormal, it may be due to the disruption of the sensory (feeling) or motor (movement) nerves or both. To determine where the neural problem may be, the physician tests reflexes in different parts of the body. See the following examples in the chart below. Check the deep tendon reflexes using impulses from a reflex hammer to stretch the muscle and tendon. The limbs should be in a relaxed and symmetric position, since these factors can influence reflex amplitude.  A reflex action, differently known as a reflex, is an involuntary and nearly instantaneous movement in response to a stimulus. Scientific use of the term reflex refers to a behavior that is mediated via the reflex arc; this does not apply to casual uses of the term reflex. Reflexes are little movements of the muscle when the tendon is tapped. A reflex can be decreased or absent if there is a problem with the nerve supply. To test your reflexes, your doctor will use a rubber hammer to tap firmly on the tendon. Just as your muscles receive signals through certain nerves, other nerves carry signals back to your spinal cord from specific sections of your skin and other tissues. Testing your sense of feeling helps your doctor find out what nerve root may be compressed. Your sense of feeling may be tested in several ways. More on nervous system The Nervous System and Reflexes from Infoplease: 1  nervous system: The Nervous System and Reflexes-The Nervous System and Reflexes In general, nerve function is dependent on both sensory and motor ... Commonly, the reflex arc includes one or more connector neurons that exert a modulating effect, allowing varying degrees of response, e.g., according to whether the stimulation is strong, weak, or prolonged. Reflex arcs are often linked with other arcs by nerve fibers in the spinal cord. The Nervous System and Reflexes. In general, nerve function is dependent on both sensory and motor fibers, sensory stimulation evoking motor response. Even the autonomic system is activated by sensory impulses from receptors in the organ or muscle. Commonly, the reflex arc includes one or more connector neurons that exert a modulating effect, allowing varying degrees of response, e.g., according to whether the stimulation is strong, weak, or prolonged. Reflex arcs are often linked with other arcs by nerve fibers in the spinal cord. Topic Overview. The nerves that carry messages to and from your legs come from your low back. By checking your muscle strength, your reflexes, and your sensation (feeling), your doctor can tell whether there is pressure on a nerve root coming from your spinal column. He or she can often also tell which nerve root is involved. A reflex can be decreased or absent if there is a problem with the nerve supply. To test your reflexes, your doctor will use a rubber hammer to tap firmly on the tendon. If certain reflexes are decreased or absent, it will show what nerve might be compressed.
https://www.laserspineinstitute.com/beendoctors/section/tests/27/reflex/194/ http://www.infoplease.com/encyclopedia/science/nervous-system-the-nervous-system-reflexes.html http://www.spineuniverse.com/exams-tests/neurological-exams-sensory-nerves-deep-tendon-reflexes http://www.neuroexam.com/neuroexam/content.php?p=31 https://en.wikipedia.org/wiki/Reflex http://www.webmd.com/a-to-z-guides/nerve-function-tests-for-evaluating-low-back-problems-topic-overview?page=2 http://www.infoplease.com/encyclopedia/science/nervous-system-the-nervous-system-reflexes.html http://www.infoplease.com/encyclopedia/science/nervous-system-the-nervous-system-reflexes.html http://www.emedicinehealth.com/nerve_function_tests_for_evaluating_low_back_problems-health/article_em.htm
what are nerve reflexes