In order to answer why the cell would need aquaporins when the plasma membrane is permeable to water, we need to understand the make-up of water and the cell membrane. The water molecule is polar with its H+ and OH- ions. Cell membranes are selectively permeable.
Anatomy of the Auricle. The auricle or pinna is a relatively large appendage on the side of the head. It is prominent in most people and plays a very important role in hearing â it directs sound waves into the ear canal. The auricle is composed of cartilage which is covered by skin.
costal cartilage a bar of hyaline cartilage that attaches a rib to the sternum in the case of true ribs, or to the immediately above rib in the case of the upper false ribs. cricoid cartilage a ringlike cartilage forming the lower and back part of the larynx. diarthrodial cartilage articular cartilage.