DEEP TENDON REFLEX Meaning and
Definition
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Deep tendon reflex, also known as the stretch reflex or myotatic reflex, is a physiological response of the body to a sudden stretch or stimulus applied to a muscle. It is an automatic, involuntary reaction that occurs due to the activation of sensory receptors in the muscle called muscle spindles.
When a muscle is rapidly stretched, such as through tapping or striking it with a reflex hammer, the muscle spindles within that muscle detect the change in muscle length and send signals to the spinal cord. These signals are then transmitted via sensory nerve fibers to the spinal motor neurons, which in turn send signals back to the muscle, causing it to contract. This reflex action helps to regulate muscle tone and maintain balance and coordination.
Deep tendon reflexes are commonly tested by healthcare professionals during physical examinations to assess the integrity and normal functioning of the nervous system. The most well-known example of a deep tendon reflex is the knee jerk reflex, where the patellar tendon is tapped just below the kneecap, resulting in a sudden and brief contraction of the quadriceps muscle. The response is graded for its intensity and speed, as alterations in these reflexes can provide valuable information about the presence of neurological disorders or abnormalities.
