Reflexes PowerPoint Presentation free download Biology Diagrams The pathway starts when the muscle spindle is stretched (caused by the tap stimulus in the knee jerk reflex). The muscle spindles are responsible for detecting the length of the muscles fibres. When a stretch is detected it causes action potentials to be fired by Ia afferent fibres. These then synapse within the spinal cord with ฮฑ-motoneurones
This monosynaptic reflex arc is variously referred to as the "stretch," "deep tendon," or "myotatic reflex," and it is the basis of the knee, ankle, jaw, biceps, or triceps responses tested in a routine neurological examination. The tap of the reflex hammer on the tendon stretches the muscle and therefore excites a volley of activity from the muscle spindles in the afferent axons.
Muscle Stretch Reflex Biology Diagrams
The stretch reflex is accomplished through several different structures. In the muscle, there are muscle spindles, whose intrafusal muscle fibers lie parallel to the muscle and sense changes in length and velocity. The afferent sensory neuron is the structure that carries the signal from the muscle to the spinal cord. The monosynaptic stretch reflex, sometimes called the muscle stretch reflex or deep tendon reflex, is a reflex arc that facilitates direct communication between sensory and motor neurons innervating the muscle. This reflex initiates inside the muscle spindle, which detects both the magnitude and rate of muscle stretch. When the muscle is subjected to a stretch stimulus, sensory impulses are
This process is called the stretch reflex. When a muscle spindle's associated muscle is rapidly stretched, the spindle can cause two things to happen: (1) it may signal its muscle to contract to prevent it from going too far, too quickly in the stretch; and (2) it can inhibit the opposing muscle (the antagonist to the muscle being stretched
Understanding the Stretch Reflex (or Myotatic Reflex) Biology Diagrams
Muscle spindles are stretch receptors within the body of a skeletal muscle that primarily detect changes in the length of the muscle. After stroke or spinal cord injury in humans, spastic hypertonia (spastic paralysis) often develops, whereby the stretch reflex in flexor muscles of the arms and extensor muscles of the legs is overly
