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.
Low-set ears and pinna abnormalities. Low-set ears and pinna abnormalities refer to an abnormal shape or position of the outer ear (pinna or auricle). The outer ear or pinna forms when the baby is growing in the mother's womb. The growth of this ear part takes place at a time when many other organs are developing (such as the kidneys). Abnormal changes in the shape or position of the pinna may be a sign that the baby also has other related problems. Common abnormal findings include cysts in the pinna or skin tags.