KINE 3020 Lecture Notes - Lecture 4: Quadriceps Femoris Muscle, Dendrite, Golgi Tendon Organ
Document Summary
Many motor tasks are performed without thinking: spinal reflex (simplest, afferent neuron interneuron alpha motor neuron, afferent neuron motor neuron, considered the basic units of movement. Autonomic but adaptable response to a sensory stimulus. Purposes: balance, postural control, avoid injury. Muscle spindles afferents (ia & ii) are involved in many reflexive movements. Stretch reflex: simplest, type ia afferent innervates & excites the alpha motor neuron of the same. Muscle (increased length shortening: posture (the current position) is maintained by the stretch reflex, fast: 50 msec. Although info is sent to the brain at the same time. Reflex triggers the response without waiting for brain analysis: e. g. when the muscle starts to lengthen . Disease of the peripheral nerves & spinal cord can be found by checking the stretch. Exaggeration of reflex: deafferented the peripheral nerves, als. Stretch reflex: responds to a stretch of muscle fibers. Inverse myotactic reflex (golgi tendon reflex: responds to a contraction / tension on the tendon.