Have the patient repeat this movement with the other foot. An inability to perform this motion in a relatively rapid cadence is abnormal. The heel to shin test is a measure of coordination and may be abnormal if there is loss of motor strength, proprioception or a cerebellar lesion. If motor and sensory systems are intact, an abnormal, asymmetric heel to shin test is highly suggestive of an ipsilateral cerebellar lesion.
Auxins promote stem elongation, inhibit growth of lateral buds (maintains apical dominance). They are produced in the stem, buds, and root tips. Example: Indole Acetic Acid (IA). Auxin is a plant hormone produced in the stem tip that promotes cell elongation.
Light is so important for plant growth that they actually bend over backwards to get their share! Think about it this way. The plant cells that are on the shady side of the plant actually grow longer than the cells on the sunny side. These longer cells grow this way because of a chemical in them called an auxin. An auxin, is a plant growth hormone that helps regulate shoot growth. Under normal light conditions auxins are spread out in the plant. But when sunlight varies, auxin is broken down on the sunnier side of the stem. The higher concentration of auxin on the shady side causes the plant cells on that side to grow more so it bends toward the light. Because light is the energy source for plant growth, plants have evolved highly sensitive mechanisms for perceiving light.