Best Answer: 1. Dilator pupillae-dilator (radial) muscle-innervated by sympathetic nervous system (Alpha-1 receptors)- increases the size of pupil (mydriasis) 2. Constrictor (circular muscle) pupillae-constricts the pupil (miosis) ex during accommodation reflex. just now. Report Abuse. Radial muscles and circular muscles. When the radial muscles contract the size of the pupil is increased. When the circular muscles contract the size of the pupil is decreased. Changing the size of the pupil controls the amount of light entering the eye.
sustain & protect. Thinning for forest health. An acre of land can only grow so much wood. One acre of fertile forestland may be able to sustain 500 little trees, or 100 big trees. Thinning is an effective and powerful forest management tool that promotes timber growth and restores forest health. When thinning a forest, slower growing or defective trees are removed to provide more space for the remaining trees to grow. The result is that available water and soil nutrients benefit those that remain, resulting in bigger, healthier trees in a shorter period of time.
Thinning is generally the least invigorating type of pruning cut and provides a more natural growth form of plants. Important in maintenance pruning, thinning cuts are used to shorten limbs, to improve light penetration into plants and to direct the growth of shoots or limbs. The two basic types of pruning cuts are heading and thinning. 2  Thinning cuts are the least invigorating type of cut and are the most effective pruning cut for maintaining woody plants in their natural form.