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.
Cartilage /ËkÉrtÉ¨lÉ¨dÊ/ is a flexible connective tissue in animals, including the joints between bones, the rib cage, the ear, the nose, the bronchial tubes and the intervertebral discs.It is not as hard and rigid as bone, but it is stiffer and less flexible than muscle.artilage is classified in three types, elastic cartilage, hyaline cartilage and fibrocartilage, which differ in relative amounts of cartilage. Chondroblasts that get caught in the matrix are called chondrocytes.